MODULE 10
Pharmacology II
2
Lifespan Considerations
Pregnant Women If possible, drug therapy should be
delayed until after the first trimester, especially when there is danger of drug-induced developmental defects.
Potential fetal risks must be compared to maternal benefits when drug therapy is required.
Minimum therapeutic dose should be used for as short a time period as possible.
3
Lifespan Considerations (cont’d)
Pregnant WomenFDA Pregnancy Categories:
Drugs in categories A and B most likely carry little or no risk to the fetus.
Drugs in categories C and D most likely carry some risk to the fetus.
Drugs in category X are contraindicated during pregnancy.
4
Lifespan Considerations (cont’d)
Pregnant Women There are certain situations that
require judicious use of drugs during pregnancy:HypertensionEpilepsyDiabetes Infections that could seriously
endanger the mother and fetus
5
Lifespan Considerations (cont’d)
Breast-feeding WomenMany drugs cross from the mother’s
circulation into breast milk and subsequently to the infant, although in small amounts because this is not the primary excretion route.
Again, the risk to benefit ratio must be evaluated.
6
Lifespan Considerations (cont’d)
ChildrenParent is important source of:
Information about the childSource of comfort for the childPartner with the health care team
during drug therapy.Should not be used to refer to a
patient under 1 year of age.
7
Lifespan Considerations (cont’d)
ChildrenDifferences in Physiology and
PharmacokineticsImmaturity of organs most
responsible Anatomic structures and
physiologic systems and functions are still in the process of developing
8
Lifespan Considerations (cont’d)
ChildrenPharmacodynamics (Drug Actions)
Some drugs may be more toxic in children and some less.
More toxic – Phenobarbital, morphine, ASA Same – Atropine, codeine, digoxin Contraindicated – tetracycline (discolor
teeth), corticosteroids (may suppress growth) Fluoroquinolone antibiotics (may damage cartilage leading to gait deformities)
Some tissues may be more sensitive – smaller doses
9
Lifespan Considerations (cont’d)
Children - Kid FactsSafe, appropriate drug therapy must
reflect the differences between adults and children.
The child’s stage of growth and development must be considered when assessing core patient variables and the interaction of core drug knowledge and core patient variables.
Pediatric drug dosages must be accurate to reduce risk of adverse effects and prevent over dosage.
10
Lifespan Considerations (cont’d)
Children - Drug Administration Choice of appropriate route and/or site
of drug administration will vary by the child’s age and size and the drug.
Special techniques may be needed to minimize traumatic effects to the child:
EMLA cream can be used to numb an area prior to an injection.
A popsicle or ice chips can be used to numb taste buds before unpleasant-tasting oral drugs.
Do not mix drug therapy into infant formula.
11
Lifespan Considerations (cont’d)
Children – Nursing ResponsiblitiesEducation about medications should be
provided for the patient, at an appropriate developmental level, and to the family.
Implement the “6 Rights.”It may often be necessary for 2 nurses
to check the medication(s). Check agency policy.
12
Lifespan Considerations (cont’d)
Older adults/Geriatric ConsiderationsShare common age-related changes
and risk factors that alter drug administration, dosage and expected response to drug therapy.
All pharmacokinetic processes are altered, placing older adults at higher risk for adverse drug effects.
13
Lifespan Considerations (cont’d)
Geriatric Considerations Pharmacokinetics:Alterations in absorption are more likely
caused by disease processes.Distribution is altered because of:
Decreased body mass Reduced levels of plasma albumin Less effective blood-brain barrier
Hepatic metabolism is slowed.Renal efficiency is decreased:
Serum creatinine levels will remain normal even though kidney function is impaired.
14
Lifespan Considerations (cont’d)
Geriatric Considerations-Pharmacodynamic Changes Receptor site changes.Blood-brain barrier allows more
drug to enter the brain.Normal aging-related decline in
organ or system function occurs.
15
Lifespan Considerations (cont’d)
Geriatric Considerations o Polypharmacy
May see multiple MDs for various illnesses and all may prescribe meds.
Consume approx 32% of all Rx drugs and 40% over the counter (OTC) drugs
Most common Prescriptions – antihypertensives, insulin, beta blockers, digitalis, diuretics, potassium (K) supplements
Most common OTC’s – analgesics, laxatives, nonsteroidal anti-inflammatory drugs (NSAIDS)
16
Lifespan Considerations (cont’d)
Geriatric Considerations Nonadherence – Lack of knowledge or
incomplete knowledge leads to misunderstanding about medication regime.
Lifestyle – Choices may have to be made between food, rent and purchase of medications.
17
Lifespan Considerations (cont’d)
Geriatric Considerations:Simplify the therapeutic regimen.Give memory aids (if necessary).Give written instructions.Determine financial access to drug
therapies.Assess cultural barriers.Titrate the dose upward slowly to
minimize adverse effects.
18
Cultural Considerations in Drug Therapy
The Law of Cultural DiversityEach patient needs to be considered an
individual, regardless of cultural, ethnic or religious beliefs.
Although members of a culture share certain beliefs and practices, individual variation will still occur. Many cultural groups in the U. S. have beliefs that reflect both their original ethnic culture and the dominant culture of the United States.
19
Ethnic Considerations in Drug Therapy
Drug polymorphism Critical in understanding a patient’s response
to drug therapy May explain many adverse and idiosyncratic
reactions Refers to how individuals metabolize differently Looks at genetics that often have a common
basis in ethnic background Opens up a new field of study in pharmacology
that has been lacking for years due to societal factors
Examples: Why does the African-American respond differently to antihypertensives, the Chinese patient require lower doses of benzodiazepines, the Caucasian respond differently to some pain medications?
20
Ethics and Drug Therapy
Nurse’s responsibility is to always be a patient advocate and remain
nonjudgmental. ANA Code of Ethics Canadian Nurses Association Code of Ethics Various Nurse Practice Acts
All share the framework for the professional practice of nursing.
All believe that, professionally, the nurse provides safe nursing care to patients regardless of the group, community, ethnicity or culture.
Nursing does not impose values or standards on the patient.
Nurses assist the patient and family in facing decisions regarding health care.
21
Botanical Dietary Supplements
For a complete list of botanical dietary supplements fact sheets, (National Institutes of Health), see : http://www.ods.od.nih.gov/Health_Information/Botanical_Supplements.aspx
Opioid & Non-Opioid Analgesics
Aspirin
NSAIDs
COX-2 inhibitor
Acetaminophen
Narcotics
The 5th Vital Sign
Pain
23
Analgesics
Definition of an analgesic:
“Medications that relieve pain without causing loss of
consciousness”
Pain is a subjective experience. The nurse must believe the patient. PET scans now can visualize brain’s responses to many kinds of pain.
24
Proposed Pain PathwayNociceptors (free nerve endings)
Afferent stimulation of sensory “A” or “C”fibers
Dorsal horn spinal cord – the location of the “gate”
3 major brain pathways:Spinothalamic, spinoreticular,
spinomesencephalic
Release of peptide substance P from unmylinated “C” fibers in dorsal horn
(Multiple neurotransmitters released)
25
Pathophysiological
Nociceptive pain Neuropathic pain Psychogenic pain
The type of pain determines the analgesic.
Neuropathic pain is often treated with anticonvulsants, tricyclic antidepressants
added onto narcotics
Many theories of pain transmission are not
completely understood.
26
Pain Transmission
These techniques also allow some non- pharmacological relief from pain:
Massage Deep pressure
Distraction Relaxation Vibration
Can be used as independent nursing intervention after assessment
The above activate the large “A” fibers.
27
Factors Influencing Pain Perception
Type of pain Acute vs. chronic Visceral vs. cutaneous Nociceptive, neuropathic,
psychogenic Intensity of pain & type of injury Inflammatory process Degree of Anxiety
28
Factors Influencing Pain Perception
Sensory input Social support Fatigue Age, sex & culture Memory & information processing Level of consciousness Type, amount, route of analgesic
29
Drugs Influencing Pain Perception
Narcotics (opioids) modify pain perception via Central Nervous System (CNS) & dorsal horn via binding to Mu, kappa & delta opioid receptors & inhibiting substance “P” and glutamate (an excitorary neurotransmitter).
Alter perception of pain via opiate receptors, and alter psychological responses via brain.
Other mechanisms to alter pain involve effects on the Autonomic Nervous System (ANS), skeletal muscle response & diagnosis.
30
Drugs Influencing Pain Perception
Nonopiate analgesics (salicylates, NSAIDS, etc.)
Control pain impulses in the periphery
Often involving the Arachidonic acid pathway responsible for inflammation and an immune response
31
Some Pain Mysteries
Phantom pain
Referred pain
Pain experienced after cordectomy
Placebo response
32
Prostaglandins
Associated with inflammation Involved in the temperature
set point of the hypothalamus Sensitize pain receptors to
mechanical and chemical stimulation
Found in many cells and body processes
33
Leukotrines
Arachidonic acid metabolites
Mediators in inflammation
Synthesized when tissue injury occurs
May be involved in rheumatoid arthritis, asthma and system wide anaphylaxis
Bronchoconstrictor and vasodilator
34
Synthesis of Prostaglandins
Arachidonic acid
Lipoxygenase
Cyclooxygenase
Leukotrines Prostaglandins
enzymes
35
TWO Enzyme FORMS
CYCLOOXYGENASE-1 & CYLOOXYGENASE- 2
COX-1 COX-2
Prostaglandins
Protects stomach lining
Inflammation Pain
36
Peripheral control of pain
Release of prostaglandin inflammation & pain
Prostaglandins mediate pain and swelling by triggering vasodilatation. Prostaglandins are synthesized by the enzyme cyclooxygenase which breaks down arachidonic acid to synthesize prostaglandin. This is the basic method of action of aspirin and NSAIDs.
37
Inhibition of Cox-1 & Cox-2
Inhibition of both Cox-1 & Cox-2 will be effective as an:
ANALGESIC ANTIPYRETIC ANTI-INFLAMMATORY AGENT AGENT TO DECREASE PLATLET
AGGREGATION
Also associated with stomach damage due to COX-1 inhibition
38
Aspirin
Inhibits both Cox-1 and Cox-2
Is used as a analgesic Is used as a anti-inflammatory agent Is used as a antipyretic But can cause stomach damage Is used to prevent coronary heart
disease (CHD) via platelet aggregation
In what other cases should aspirin NOT be used?
39
Aspirin adverse effects & interactions
Tinnitus – sign of toxicity Dyspepsia Highly protein bound so it displaces
other medications: oral anticoagulants, oral hypoglycemics, some anticonvulsives.
G.I. Bleeding increased with glucocorticoids, alcohol
High doses may cause excessive bruising Highly lethal if taken in overdose - No
known antidote Caution with asthmatic patients (may
have aspirin allergy also)
40
Hold giving Aspirin
41
Children under 15 withviral infection
Reye’s syndrome is associated with aspirin use.
42
NSAIDSNon-Steroidal Anti-Inflammatory Drug
First line treatment for inflammation Both COX-1 & COX-2 inhibitors Mild to moderate pain of various types Good for dysmenorrhea Antipyretic Reversibly inhibit platelet
aggregation (less than aspirin because aspirin has irreversible inhibition)
INHIBIT THE PRODUCTION OF PROSTAGLANDINS THAT MEDIATE PAIN AND INFLAMMATION
43
Side effects & Interactions of NSAIDs
G.I. Bleeding, dyspepsia Liver toxicity or renal damage with
large doses, prolonged use Highly bound to plasma protein so
displace other medications, leading to exacerbation of their side effects
These adverse effects can occur with oral or parenteral routes and even if
enteric coated.
44
Don’t give aspirin or NSAIDs
Patients with ulcers
Patients going to surgery
Patients with an allergy to aspirin
Alcoholic patients
When patient is nauseated or vomiting
Patients on glucocorticoids (without M.D. order)
Patients taking ACEIs (Angiotensin Converting Enzyme Inhibitors)
Caution with NSAIDs in patients with CHF
45
COX-2 INHIBITOR
Celecoxib (Celebrex) Approved for osteoarthritis and rheumatoid arthritis
Acute pain & dysmenorrhea Do not give if sulfa allergy
Has anti-inflammatory properties
Only COX-2 inhibitor currently available
46
Acetaminophen (Tylenol)
Is a very weak inhibitor of both Cox-1 and Cox-2
Is used as an antipyretic Is used as an analgesic Can not be used as an anti-
inflammatory agent Does not stop platelet aggregation May work by inhibiting
prostaglandin synthesis in the CNS
47
Acetaminophen
Is the drug of choice for mild to moderate pain
Is often combined with opioids to treat moderate to severe pain
Will cause liver failure in LARGE doses or prolonged use (2.4 to 4 grams/day)
Liver failure with alcohol due to metabolic pathways
Ceiling effect Overdose is difficult to treat - use
acetylcysteine
48
Acetaminophen
Young children, older adults, daily drinkers of 3 or more alcoholic beverages and those with kidney or liver disease are at risk for accidental acetaminophen poisoning
Acetaminophen found in many pharmaceuticals Vicodin ES (5 tabs Q. D. = 4 gm) Tylenol extra-strength (8 tabs = 4 gm) What other OTC medications might
contain acetaminophen?
49
Neuropathic Pain
Difficult to treat Use of opioids does not completely control
pain Usually add on another medication from a
different class (co-analgesic agents) immipramine (Tofranil) Tricyclic
antidepressant -TCA gabapentin (Neurontin) Anticonvulsant Duloxetine (Cymbalta) newest SNRI
(serotonin norephinephrine reuptake inhibitor) - also used for depression
Effexor is another medication in this class
New pregabalin (Lyrica) anticonvulsant - alpha2 - delta ligand
+ other medication classes
50
Natural, synthetic and semisynthetic
ALL COMPARED TO MORPHINE
51
Opiates
Narcotics: Very strong pain relievers
Opiates: Pain relievers that contain
opium, derived from opium, or are chemically related to opium
52
Pain Transmission
o Body has endogenous neurotransmitters
o Endogenous neurotransmitters are: enkephalins & endorphins (morphine-like peptides) produced by body to fight pain
o Opiates bind to these natural endogenous opioid receptors
o Inhibit substance P in dorsal horn of spinal cord
53
Chemical Classification of Opioids
CHEMICAL CATEGORY & examplesNatural: codeine, morphine
Semi-synthetic: hydrocodone (Vicodin) oxycodone + salicylate
Synthetic: meperdine (Demerol) can beneurotoxic and cause
confusion/seizure - NEVER give to patients with
Parkinson’s Diseasebutalbital (Fiorinal)
(Percodan)
54
Opiates
Three classifications based on their actions:
agonist agonist-antagonist partial agonist
55
CNS Opiate effects/uses
Analgesia Cough suppression Euphoria Reduces fear/anxiety Raises pain threshold (decreased
awareness) Sleep induction Respiratory depression Pupil constriction (miosis) Nausea and vomiting
56
Peripheral Nervous System OPIATE Effects
Constipation Urinary retention Diaphoresis & flushing Hypotension due to
vasodilatation
57
Narcotic analgesic routes
PCA example Morphine (acute pain) Transdermal example Duragesic patch
(fentanyl) (chronic pain) Epidural example fentanyl or morphine Oral example MS Contin (morphine)(chronic
pain) I.M injections example meperidine (acute
pain) (Demerol). Do not give for more than a day – neurotoxic, lowers seizure threshold, not first line agent. Metabolite normeperidine neurotoxic and may cause psychosis in the elderly patient.
58
Gold Standard is Morphine No ceiling effect
ADVANTAGES Decreased
awareness Decreased anxiety Increased sleep Decreased pain
perception
DISADVANTAGES Hypotension Constipation Nausea Respiratory
depression Itching
Secondary effects of cough suppression and constipation are used therapeutically
59
Oral Morphine examples
Oxycontin (oxycodone) MS Contin (morphine) Kadian (morphine) Oramorph SR (morphine) Avinza (morphine)
New Q day dosing (Do not crush, chew or dissolve the caps or could deliver fatal dose)
If can not swallow, O.K. to open & sprinkle the beads on applesauce
60
Mixed agonist-antagonists
Pentazocine (Talwin)Buprenorphine (Bupreneax)Butorphanol (Stadol)Ultram (Tramadol) - mechanism of action
not clearly understood, weak bond to opioid receptors & inhibits reuptake of norepinephrine (NE) & serotonin (5-HT) may cause chemical dependency
These medications are rarely used
DO NOT GIVE THESE MEDICATIONS TO PATIENTS WHO ARE DEPENDENT ON
NARCOTICS.
61
Opiate Antagonists/blockers
Naloxone (narcan) opiate antagonist [competitive]
Naltrexone (ReVia) now used to help alcoholics stay abstinent
62
Opiates
Opioid Tolerance:
a common physiologic result of chronic opioid treatment
means larger doses of opioids are required to maintain the same
level of analgesia
63
Opiates
Physical Dependence The physiologic adaptation of the
body to the presence of an opioid
Opioid tolerance and physical dependence are expected with long-term opioid treatment and should not be confused with psychological dependence [addiction].
64
Opiates
Psychological Dependence[addiction]
A pattern of compulsive drug use characterized by a continued craving for an opioid and the need to use the opioid for effects other than pain relief
65
Opiates
Misunderstanding these terms leads to ineffective pain management and contributes to the problem of under treatment.
66
Opiates
Physical dependence on opioids is known when the opioid is abruptly discontinued or when a opioid antagonist is administered. narcotic withdrawal opioid abstinence syndrome
67
Opiates
Narcotic withdrawal Opioid abstinence syndrome
Manifested as: (flu-like symptoms)Anxiety, irritability, chills and hot flashes, joint pain, lacrimation, rhinorrhea, diaphoresis, nausea, vomiting, abdominal cramps and diarrhea
68
Drugs Affecting the Autonomic Nervous System
69
Photo Source: National Institutes of Health, Public Domain, http://catalog.niddk.nih.gov/ImageLibrary/searchresults.cfm
70
Sympathetic NS
FIGHT FLIGHT&
71
Parasympathetic N.S.
BREED & FEED
72
Adrenergic Drugs
Mechanism of action Mimic Sympathetic Nervous System (N.S.) Have sympathomimetic properties Have sympatholytic action also since they
oppose the parasympathic N.S. Catecholimines are neurotransmitters
involved in adrenergic system DA (dopamine) NE (norepinephrine) E
(epinephrine) Energizing neurotransmitters
Direct-acting, indirect acting and mixed adrenergics
73
Adrenergic Drugs (cont’d)
Indications Bronchodilation (albuterol) Cardiac stimulation, alpha1, beta 1,
beta 2, increase blood pressure (dopamine, isoproterenol)
Mental alertness & wakefulness (monafnil)
Appetite suppression (adipex) Decongestion (pseudoephedrine) Open angle glaucoma (dipivefrin)
produces mydriasis = pupil dilation ADHD (methylphenidate)
Adverse effects Tachycardia, hypertension, anxiety,
insomnia, psychological dependency
74
Alpha -Adrenergic Blocking Drugs
Drug examples: ergotamine tartrate (Egostat), Phenoxybenzamine, phentolamine (Regitine)
Indications: Raynaud’s disase, hypertension secondary to pheochromocytoma, extravasation of vasopressors, vascular headaches
Adverse effects: nasal congestion, orthostatic hypotension, tachycardia, dizziness, (Gastrointestinal) GI irritation, and miosis. Ergotamine may cause chronic poisoning.
75
Beta-Adrenergic Blocking Drugs
Drug examples: selective for beta 1 receptors - atenolol, metoprolol Non-selective for beta 1 & 2 receptors - propranolol (contraindicated in pt. with COPD, asthma, depression)
Indications: treat hypertension, angina, tachyarrhythmias, CHF, Post MI because they are cardio-cardio-protective
Contraindications: bradyarrhythmias, bronchospasm, heart blocks
Adverse effects: arrhythmias, bradycardia, bronchospasm, nausea, vomiting, diarrhea, increased sensitivity to cold, rebound HTN if stopped abruptly
76
Cholinergic Drugs
cholinergics cholinergic agonists
parasympathomimetics Sympatholytics
All are terms that refer to drugs that stimulate the Parasympathic Nervous
System
MIMIC ACETYLCHOLINE Cholinergic drugs
77
Cholinergic Drugs
Cholinergic receptors [two types]
Based on location & their action
Nicotinic {N}&
Muscarinic {M}
78
Drug & Side Effects of Cholinergics
SalivationLacrimationUrinary incontinenceDiarrheaGastrointestinal crampsEmesis
(Also bronchospasm, decreased intra ocular pressure (IOP), decreased heart rate, increased bronchial secretions, miotic, sweating)
79
Cholinergic Drugs Indications Direct- acting
Cholinergic agonists – used to treat open angle glaucoma and dry eyes and to stimulate bladder
Indirect-acting Cholinesterase inhibitors (reversible) – for
Alzheimer’s & to treat myasthenia gravis (MG) and open angle glaucoma not responsive to other agents – prevents postoperative paralytic ileus
Drug examples – bethanechol, pilocarpine Bethanechol – treat nonobstructive urine retention,
neurogenic bladder, adynamic ileus Pilocarpine – treat glaucoma
Contraindications Possible urinary or GI obstruction and pregnancy
80
Cholinergic-blocking drugs
Class of drugs that block or inhibit the actions of Acetylcholine in the Parasympathetic Nervous System
anticholinergics parasympatholytics
antimuscarinic agents
81
Cholinergic-blocking drugs (also called anti-cholinergic drugs)
Inhibit nicotinic {N} or muscarinic {M} receptors
Anticholinergic effects are the result of muscarinic blockage, primarily on the post synaptic receptor of the Parasympathetic Nervous System.
There are medications that are designed for their anticholinergic effect.
Many medications have anticholinergic side effects that are NOT wanted.
82
Cholinergic-blocking drugs
Atropine Preop for secretion control, therapeutic
anticholinergic effect, Bradycardia, anticholinesterase effect for insecticide poisioning CNS excitation
Dicyclomine (Bentyl) Irritable bowel syndrome (IBS)
Propantheline bromide (Pro-Banthine) Adjunct in Treatment of peptic ulcer, IBS,
pancreatitis
83
Cholinergic-blocking drugs
Glycopyrrolate (Robinul) Control of secretions intraoperative,
preop control of secretions, preop for electro convulsive therapy (ECT)
Scopolamine (Transderm-Scop) Prevents motion sickness
Orphendrine (Norflex) A central acting anticholinergic muscle
relaxant
84
Therapeutic effects of Anticholinergics
Tolterodine (Detrol) & Trospium Chloride (Sanctura) newOveractive bladder
Benztropine (Cogentin)Parkinson’s DZ and EPS (neurological
side effects) from antipsychotics
Ipratropium Bromide (Atrovent)Inhaled drug used to treat COPD,
asthma, little systemic effect because inhaled
85
Drug Interactions
ADDITIVE EFFECTS WITH: antihistamines, anticholinergics, phenothiazines,tricyclic antidepressants, MAOI’s (monoamine oxidase inhibitor)
Antihistamines have anticholinergic effects
This could cause confusion & or psychosis in the ELDERLY PATIENT.
Contraindicated in: glaucoma, benign prostatic hypertrophy (BPH), Cardiac disease and obstructive bowl & asthma unless inhaled
86
Secondary effects/Side effects
(anticholinergic)
Xerotomia (dry mouth) Blurred vision Urinary retention Decreased perspiration Constipation Tachycardia
These are common in many of the psychoactive drugs
87
Neuromuscular Blocking Agents
Prevent nerve transmission in certain muscles, leading to paralysis of the muscle at neuromuscular junction by binding to Ach receptor
Indications – Maintains controlled ventilation during mechanical ventilation or during endotracheal intubation
Contraindications – Drug allergy, previous history of malignant hypertension, penetrating eye injuries and narrow-angle glaucoma
Side/Adverse Effects – Hypokalemia, dysrhythmias, fasciculations, muscle pain, increased intraocular and intracranial pressure and apnea
88
CNS Depressants Hypnotics and Sedatives
Classified into barbiturates, benzodiazepines and miscellaneous agents
Act primarily on the brainstem; sedative and hypnotic effects are dose related.
89
Barbiturates
Habit forming and have narrow therapeutic index
Contraindications –pregnancy, significant respiratory difficulties and severe liver disease
Side Effects – Drowsiness, lethargy, dizziness, hangover, and paradoxical restlessness or excitement
Adverse Effects – Vasodilatation, hypotension blood dyscrasias, hypersensitivity reactions
Interactions – synergistic with other Central Nervous System (CNS) depressants
Can be lethal in overdose Can have lethal consequences of
uncontrolled withdrawal
90
Short-term treatment of insomnia (rare) Sedation in lower doses Ultra-short acting for anesthesia
induction Pre-op medication Epilepsy, mainly status, but the long-
acting Phenobarbital can be used as anticonvulsant - at small doses does not produce sedation, but seizure activity
Not used as often today because of newer agents for sleep, seizure and anxiety
Barbiturates Uses
91
Action and General Characteristics of Benzodiazepines
Specific for cerebral cortex and limbic system
Also called anxiolytics Increase action of GABA + other
inhibitory neurotransmitters Highly lipid soluble to facilitate
crossing into CNS Highly bound to plasma protein Metabolized by the liver, some with
long duration of action due to active metabolites
92
Benzodiazepine Uses Anxiolytics – examples: alprazolam (Xanax) Anticonvulsants – examples: clonazepam
(Klonopin) and diazepam (Valium) Anesthesia induction – examples:
midazolam (Versed), diazepam (Valium) Muscle Relaxant – example: diazepam
(Valium) Withdrawal from alcohol – example:
chlordiazepoxide (Librium), diazepam (Valium)
Hypnotics – examples: flurazepam (Dalmane), and temazepam (Restoril) do not depress REM sleep; but prevent deep sleep (not natural)
93
Secondary/side effects of Benzodiazipines
Daytime sedation Ataxia Dizziness Anterograde amnesia Idiosyncratic paradoxical excitement SELDOM FATAL IF TAKEN ALONE Can be dangerous for the elderly
because of fall potential
94
Centrally Acting Muscle Relaxants
Primarily used for the relief of painful musculoskeletal conditions–muscle spasms and spasticity.
Side Effects – Euphoria, lightheadedness, dizziness, drowsiness, fatigue and muscle weakness - usually short-lived
Adverse Effects – GI upset, headache, slurred speech, constipation, sexual difficulties in men, hypotension, tachycardia and weight gain
95
Anticonvulsant Medication
Congenital abnormalities Metabolic disorders – hypocalcemia Trauma – accidents Tumors – brain plus status post
craniotomy Vascular diseases – stroke Degenerative disorders- Alzheimer’s Infectious diseases – meningitis, AIDS Fever & toxins Medications – example = antipsychotics Alcohol withdrawal + hypomagnesemia
Causes of SeizureCauses of Seizure
96
Types of Seizureaccording to International League Against Epilepsy
Partial Seizures: focal area of brain initiates seizure
Simple partial: focal symptoms, aura, conscious
Complex partial: simple then impairment in consciousness
Generalized partial: spread to both hemispheres
97
Types of Seizure
Generalized Seizures: both hemispheres usually effected, unconscious
Absence seizures: impairment of consciousness, autonomic components, usually in children/adolescence
Tonic-clonic: (grand mal) tonic is muscle stiffing, clonic is jerking
Monoclonic: single or multiple jerks
98
Status Epilepticus
Single seizure lasting for 20 minutes or longer
Or recurrent generalized seizures without regaining of consciousness in between each seizure episode
Considered a medical emergency
99
Possible Action of Anticonvulsants
Pharmacologically distinct action for each group of anticonvulsants is PROPOSED
Many mediate actions by limiting discharge from a focal point – surrounding it
Others elevate seizure threshold through neurotransmitters or ions
100
Possible General Mode of Action
Increase concentrationIncrease concentration
of GABA byof GABA by
Blocking reuptake into glia & nerve endings
Inhibiting enzymes that catabolize GABA
Facilitating GABA & other inhibitory receptors
101
Mode of Action other than potentiation of GABA
Suppression of calcium influxInhibition of voltage-sensitive sodium channelsBinding to the amino acid glycine (neurotransmitter & inhibitory A.A.) at receptor siteDecreasing metabolism of glutamate
EXACT MODE OF ACTION NOT KNOWN
Agent chosen depends on type of seizure, age, sex, pharmacologic properties, side effects and cost
102
Anticonvulsants
FIRST LINE AGENTS - USED AS MONOTHERAPY for Tonic Clonic Seizures
Phenytoin ( Dilantin) Carbamazepine (Tegretol) Valproic acid (Depakene or
Depakote) Primidone (Mysoline) Phenobarbital
103
Anticonvulsants
FIRST LINE AGENTS USED AS FIRST LINE AGENTS USED AS MONOTHERAPY forMONOTHERAPY for Partial Partial SeizureSeizure
Carbamazepine (Tegretol) Valproic Acid (Depakene or Depakote) Lamotrigine (Lamictal) Topiramate (Topamax)* Gabapentin (Neurontin)*
* Not FDA approved for monotherapy, but studies support
104
Anti-convulsant Drugs(Antiepilieptics)
Indications: Prevention and control of seizures Main adverse effects of most anticonvulsants
are mental confusion and drowsiness Interactions of many older meds:
Potentiate CNS depressants and alcohol Concurrent use with tricyclic antidepressants or
phenothaizines lowers the seizure threshold and decreases the effectiveness of anticonvulsants
Many drugs alter hepatic metabolism of anticonvulsants leading to decreased serum levels and loss of seizure control and toxicity
Phenytoin’s cytochrome P-450 enymatic reaction inhibits atazanavir’s action (depakote becomes the drug of choice in this example).
105
Anti-convulsant Drugs Hydantoins Drug examples: Mephenytoin, phenytoin
(Dilantin) Indications: treat tonic-clonic (grand
mal) seizures and complex partial seizures, arrhythmias, and painful condition such as trigeminal neuralgia
Adverse effects: (long term) gingival hyperplasia, liver function abnormalities, blood dyscrasias, (toxicity) as evidenced by diplopia, nystagmus, ataxia, and drowsiness
Caution driving or operating equipment because of mental confusion
106
Anti-convulsant Drugs
Tell patient to use alternate birth control if on the pill
Supplement with Vitamin D, Calcium and folic acid
Interactions with Calcium Channel Blockers, Antipsychotics and steroids
P-450 = many interactions
107
Anti-convulsant Drugs
Interactions…Oral tube feedings with osmolite or
isocal may interfere with absorption of oral dilantin diminishing drug’s effectiveness
IV dilantin precipitates with D5W. Characteristics of fosphenytoin
(Cerebyx) – preferred over IV Dilantin Prodrug of phenytoin Rapidly converted by blood and liver
enzymes to phenytoin (Dilantin) Given I.V. only
108
Anti-convulsant Drugs
Barbiturates and deoxybarbiturates Examples: Mephobarbital, phenobarbital,
primidone Indications:
Treat tonic-clonic seizures, partial seizures and insomnia
Used as adjuncts to anesthesia Adverse effects: Dizziness, drowsiness,
hypotension, respiratory depression with high doses
Interactions: Drugs decreases serum dilantin level when used concurrently
Primidone plus phenobarbital may cause phenobarbital toxicity
109
Anti-convulsant Drugs
Benzodiazepines Examples: clonazepam (Klonopin)
Diazepam (Valium)
Indications: treat absence seizures, status epilepticus, anxiety and skeletal muscle spasms.
Adverse effects: ataxia, drug dependence, respiratory and cardiovascular depression
110
Valproic acid (Depakene) Divalproex (Depakote)
Low side effect profile, well tolerated May cause liver failure (rare) in first
6 months of therapy Lethargy, muscle weakness, sedation Leukopenia Ataxia Depakene causes nausea/vomiting Interacts with many other
anticonvulsants
111
Nursing Considerations
Good for generalized and partial seizure
Monitor blood levels Monitor CBC and liver function tests Highly protein bound, do not take
with NSAIDs, aspirin & other drugs that alter coagulation
Potentiates CNS depressants Reassure patient of alopecia, hair
will re-grow Used as mood stabilizer for bipolar
disorder and has FDA approval for this
112
Carbamazepine (Tegretol)
Blood dyscrasias * Notify health care provider
Liver toxicity Rash Drowsiness Low side effect profile – well
tolerated
* Immediately discontinue & switch to another agent
113
Nursing Considerations
Low behavioral and toxicologic profile Good for both generalized and partial
seizures Autoinduction – dosage needs
monitoring via blood levels, decreases after initial doses
Advise alternate birth control if on pill Monitor CBC for bone marrow
depression Used “off label” as mood stabilizer for
bipolar disorder
114
Lamotrigine (Lamictal)
Monotherapy in partial seizures Well tolerated No weight gain, no sedation Rare, but can be associated with
life threatening rash (Stevens-Johnson syndrome)
Nausea, vomiting, weight loss (rare)
Dizziness, ataxia
115
Nursing Considerations
Discontinue at once if rash/inform health care provider
Nurse asks patient every visit Taper on very slowly to avoid rash – 25 mg
Q 2 weeks until 200 mg No blood levels required Note many anticonvulsants raise or lower
plasma levels Monitor for adverse reactions if not
monotherapy May reduce effectiveness of estrogen Used for mood disorder in bipolar, good for
depressive side, and has FDA approval for this
116
Topiramate (Topamax)
Adjunctive therapy in partial and generalized seizures (studies support monotherapy)
Well tolerated Fatigue Confusion Difficulty concentrating, speech
problems (unable to recall words) Nausea Weight loss No blood levels required
117
Gabapentin (Neurontin)
Adjunct therapy for partial seizures (studies demonstrate monotherapy)
Excellent side effect profile Main problem is initial sedation, ataxia Not metabolized by liver so no interactions
with other anticonvulsants Used extensively for neurogenic pain Excellent for elderly and those on poly
drugs No blood levels required Used “off label” as mood stabilizer for
bipolar disorder but no FDA approval for this
118
Other uses for Anticonvulsants
Mood stabilizers Migraine headache Neurological pain Chronic pain syndrome Anxiolytics
119
Anti-Parkinsonian Drugs Groups of Drugs Used
Antidyskinetic Drugs or anticholinergics Antihistamines (have anticholinergic
effects) Dopaminergics
Dopaminergic agonistsMAOI-B (monoamine oxidase inhibitor)COMT Inhibitors (catechol-0-methyl-transferase)
120
Anti-Parkinsonian Drugs
Dopaminergic agonists are mainstayContraindications and precautions:
Used with caution in patients with residual arrhythmias after MI, history of peptic ulcer, psychosis or seizure disorders
Contraindicated with narrow angle glaucoma Used with caution for patients with bronchial
asthma, emphysema, or severe cardiovascular, pulmonary, renal, hepatic or endocrine disease
Adverse Effects: Dizziness, confusion, mood changes,
orthostatic hypotension, nausea, vomiting, hallucinations
121
Anti-Parkinsonian Drugs
General Information Mechanism of of action: Restore the natural
balance of the neurotransmitters in CNS to decrease S/S of Parkinson’s Disease. Imbalance between Achetylcholine (ACH) and Dopamine. Too much ACH and too little dopamine. Meds correct this.
Dopaminergic agonists Mechanism of Action is to increase the amount of
DA available in the CNS or enhance the neurotransmission of Dopamine
Medication examples: Levodopa restores dopamine levels Amantadine increases the amount of dopamine in
the brain Pramipexole (Mirapex) – newer DA receptor agonist Ropinirole (Requip) – newer DA receptor agonist
122
Anti-Parkinsonian Drugsanticholinergics
Drug examples: Benztropine (Cogentin) Trihexyphenidyl (Artane) Procyclidine (Kemadrin)
Indications: Bradyarrhythmias, dyskinesia, parkinsonism, peptic ulcer
and bowel spasms Nausea, vomiting, induce mydriasis, decrease salivation
and bronchial secretions before surgery Contraindications:
Narrow-angle glaucoma, severe hemorrhage, uncontrolled tachycardia, urinary tract/GI obstruction, BPH
Adverse effects: Blurred vision, conjunctivitis, and photophobia,
tachycardia, constipation, dry mouth and urinary hesitancy
CAN CAUSE PSYCHOTIC CONFUSION IN THE ELDERLY when drugs with anticholinergic effects are combined.
123
Two Newer class to treat Parkinsons
Selegiline (Eldepryl)
MAOIB (monoamine oxidase inhibitor – B) May have neuroprotective effects slowing the
progression of the Disease Tolcapone (Tasmar) & entacapone (Comtan)
Catechol O-methyltransferase (COMT) inhibitors = newest class
Not used as monotherapy, but as add on to levadopa to increase its efficacy.
Tasmar has been associated with liver dysfunction.
124
Two classes that reduce dosage of Levadopa
MAOI-B DA in brain by inhibiting its metabolism by MAO. Form “B” metabolizes DA. At oral doses < 10mg Q.D. like MAOI- A so acts more on tyramine NE, E, DA & 5H-T. No food restrictions with low doses.
COMT inhibitors work by inhibiting the enzyme catechol-O-methyltransferase the 2nd enzyme involved in the metabolism of levodopa - so increased amount of levodopa available.
125
Wearing off syndrome
Doses need to be adjusted upward and downward as adverse mental changes occur or Parkinson’s symptoms worsen.
Changing doses is done slowly.
126
Advanced Parkinson’s
A new DA agonist Apomorphine (Apokyn) given S.Q. is available for advanced Parkinson’s as a rescue drug for acute rigidity.
This is temporary add on, not replacement. N/V. Rx for antiemetic.
Not 5-HT3 antagonists like ondansetron (Zofran) because of hypotension.
Use trimethobenzamide (Tigan). Why do you NOT want to use prochlorperazine (Compazine)??
127
Drugs used to Treat Alzheimer’s
Cholinesterase inhibitors Increase Acetylcholine (Ach) in key
areas of brain (cerebral cortex) Reversible cholinesterase inhibitors Used to Treat mild to moderate disease Do not reverse symptoms; slow
progression Check P450 for drug interactionsExamples Donepezil (Aricept) Tacrine (Cognex) (1st, most adverse
effects, not used today) Rivastigmine (Exelon) – newer {may
have greater efficiacy}
128
New class to Treat Alzheimer’s
Memantine (Nameda) Released Jan. 2004 for
Treatment of moderate to severe Alzheimer’s Disease
May have more favorable side effect profile than Ach inhibitors
May be possible to combine with ACh inhibitors for better result
129
Drugs Affecting the Cardiovascular and Renal
Systems
Drugs to Treat:
Congestive heart failure
Hypertension
Angina
130
Inotropic (increase force of contraction)
Drugs and Cardiac Glycosides Indications
Used to treat CHF in combination with other medications.
Control ventricular rate in atrial fibrillation, atrial flutter, paroxysmal atrial tachycardia
Contraindications and precautions Uncontrolled ventricular arrhythmias, constrictive
pericarditis, complete heart block Increased risk of toxicity with hypercalcemia,
hypokalemia, hypomagnesemia, hypothyroidism, or renal failure
Very narrow therapeutic index Elderly patients more sensitive to toxic drug
effects Adverse effects – bradycardia, fatigue, weakness,
nausea, vomiting, diarrhea, visual disturbances Monitor pulse – hold if less than 60/min. apical Do not increase longevity in CHF
131
Inotropic Drugs and Cardiac Glycosides
Interactions K-wasting diuretics and other drugs causing K loss
increase risk of toxicity Amiodarone, diflunisal, diltiazem, nifedipine,
quinidine, verapamil increase the serum drug level and may cause toxicity
Concurrent use of beta adrenergic blocking drugs causes additive bradycardia
Antacids, cholestyramine, and colestipol decrease the absorption of cardiac glycosides
Digitalis preparations Examples: Digitoxin (long ½ life –not used often),
digoxin Nursing responsibilities
Digoxin excreted unchanged by the kidneys, dosage must be reduce with renal impairment
Monitor serum digoxin levels to prevent toxicity Digoxin Immune Fab IV to reverse toxicity
132
Antihypertensive Drugs
Antihypertensive drugs Indications
HTN not controlled by life style modifications Classes
Beta-adrenergic blocking drugs, angiotensin-converting enzymes (ACE) Inhibitors, angiotensin-receptor blockers,(ARB’s), calcium channel blockers, alpha 1 blockers, centrally acting alpha 2 agonists, diuretics, peripheral acting vasodilators
Contraindications and precautions Each class has own action, side effects,
specific recommendations and adverse reactions
133
Antihypertensive Drugs2nd line agent
Peripheral vasodilating drugs Drug examples: hydralazine Mechanism of action: exert direct
action on both arteries and veins to decrease peripheral vascular resistance (with beta blockers)
Indications: treatment for hypertension and hypertensive crisis
Adverse effects: fluid retention, tachycardia, orthostatic hypotension, severe hypotension and nausea
Nursing responsibilities Closely monitor for fluid volume excess Rarely used
134
Antihypertensive Drugs ACE Inhibitors (1st line agent)
Drug examples: benazepril, catopril, enalapril, fosinopril, lisinopril
Mechanism of action: block conversion of angiotensin I to angiotensin II
Mode of Action Vasodilation due to inhibition of Renin Angiotension
Aldosterone system, decreased blood volume due to decreased (Sodium) Na+
Adverse effects: dizziness, light-headedness, fainting, tachycardia, palpitations, rash, proteinuria
Nursing responsibilities Not effective with African Americans Do not give with Na+ sparing diuretics Monitor for dry cough Contraindicated in pregnancy and renal stenosis Not to be given with lithium and caution with NSAIDs
Indications: HTN, CHF, diabetes, Angina
135
Antihypertensive Drugs Calcium channel blockers (1st line
agent) Drug examples:
Amlodipine, diltiazem, felodipine, verapamil, nifedipine Mechanism of action:
Dilate vessels by blocking the slow channel, preventing calcium from entering the cell
Adverse effects: Grapefruit juice can cause toxic overdose Dizziness, AV blocks, headache, edema, flushing,
nausea, constipation, bradycardia P-450 interaction with other meds Do not give with grapefruit juice- can cause toxic
overdose Nursing responsibilities
Watch for weight gain if CHF Indications: Angina, arrhythmias, HTN
136
Antihypertensive Drugs
Diuretics – thiazide (1st line agent) Drug examples: chlorothiazide,
hydrochlorothiazide Mechanism of action: inhibit sodium and
chloride reabsorption, distal tubule, reduce blood volume
Adverse effects: Fatigue, dizziness, orthostatic hypotension, rash,
hypokalemia, hyperglycemia Indications: 1st line for HTN, take in the morning
Diuretics – loop Mechanism of action: Loop of Henley, reduce
blood volume example: furosemide (Lasix) Adverse effects: electrolytes Indications: CHF
137
Antihypertensive Drugs
Selective Beta Blockers – 1st line agent
Drug examples: Atenolol Mechanism of action: Selectively block beta 1
receptors in the heart so slows heart rate – chronotropic effect and – inotropic effect
Adverse effects: Bradycardia, rebound HTN if abruptly stopped, fatigue, dizziness, dyspnea
Indications: HTN, Prophylaxis for angina, CHF, post M.I. for cardioprotective effects
Nursing responsibilities: Monitor pulse, watch for drug interactions (CCBs), potentiated by alcohol and other CNS depressants, give cautiously with asthma patients
138
Antihypertensive Drugs
Angiotensin-receptor blockers Alpha 1 blockers Centrally acting alpha 2
agonists
All 2nd line agents
139
Antianginal Drugs Mechanism of action:
Reduce myocardial oxygen demand or increase coronary blood supply
Indication: Angina pectoris
Contraindications: Hypotension, uncorrected hypovolemia
Adverse effects: Flushing, headache, orthostatic hypotension
Interactions: Produce additive hypotension when used with
alcohol, antihypertensives, beta-adrenergic blocking drugs or calcium channel blocker drugs for erectile dysfunction.
140
Antianginal Drugs Nitrates
Drug examples: Erythrityl tetranitrate, isosorbide dinitrate
(Isordil) Nitroglycerin, Nitro-BIDMechanism of action:
Produce vasodilation. Decrease preload and afterload, and reduce myocardial oxygen consumption
Indications: Management of angina, and chronic
anginal attacks Beta Blockers and Calcium Channel
Blockers also for long term management
141
Diuretic Drugs Thiazide and thiazide like diuretics
Drug examples: Clorothiazide, hydrochlorothiazide
Mechanism of action: Increase sodium and water excretion by inhibiting sodium reabsorption in the distal tubule of the kidney
Contraindications: Sensitivity to sulfonamides Adverse effects: Hypokalemia, hyperglycemia,
arrhythmias, orthostatic hypotension, weakness, muscle cramps, photosensitivity reactions
Interactions: Decrease excretion of lithium causing toxicity Concurrent use with other K-depleting drugs and
cardiac glycosides may cause low K and risk of digitalis toxicity
NSAID may reduce response to thiazide diuretics Do not take if allergic to sulfa drugs
142
Diuretic Drugs
Loop diureticsDrug examples:
Bumetanide (bumex) ethacrynic acid, lasix, torsemide
Mechanism of action: Inhibit sodium and chloride reabsorption
from the loop of Henle and the distal tubuleAdverse effects:
Metabolic alkalosis, hypovolemia, dehydration. Hyponatremia, hypokalemia, hypochloremia, hypomagnesemia, photosensitivity, orthostatic hypotension
143
Diuretic Drugs K-sparing diuretics
Drug examples: Amiloride, spironolactone, triamterene
Mechanism of action: Act at the distal tubule to cause excretion of
sodium, bicarbonate, and calcium and conservation of K
Adverse effects: Hyperkalemia, nausea, vomiting, diarrhea
Interactions: Decrease excretion of lithium Concurrent use with ACE inhibitors or K
increases risk of hyperkalemia NSAIDs may reduce the effects of K sparing
diuretics. Give cautiously with renal insufficiency patients
144
Diuretic Drugs Osmotic diuretics
Drug examples: Mannitol, Urea
Mechanism of action: Increase osmotic pressure of the
glomerular filtrate inhibiting reabsorption of water and electrolytes
Osmotic diuretics create an osmotic gradient in the glomerular filtrate and the blood
Adverse Effects: Hyponatremia, dehydration, circulatory
overload, rebound IICP
Antilipemics
DRUGS TO LOWER CHOLESTEROL:VDRL, LDL and TGs
WE EAT TOO MUCH FAT
in the typical American diet.
146
Syndrome Xmetabolic syndrome
Glucose intolerance
Insulin resistance
Hypertension
Dyslipidemia
Hypertriglyceridemia
Male-shaped obesity
Female hip-to-waist ratio
Associated with
Cardiac Disease
147
Classes that lower lipids
HMG-CoA Reductase Inhibitors or Statins
Nicotinic Acid Fibric Acid Derivatives Cholesterol Absorption
Inhibitors
•Bile Acid Sequestrants
148
Anticoagulant, antiplatelet and thrombolytic drugs
Anticoagulant drugs prevent extension and formation of clots by inhibiting factors in the clotting cascade
Thrombolytic drugs activate plasminogen, leading to its conversion to plasmin
Antiplatelet drugs interfere with platelet aggregation, preventing thromboembolic events
149
Common Pathway
Prothrombin
(factor II)
Thrombin
Fibrinogen
Fibrin clot
Factor X
Heparin + antithrombin =
Activated Heparin
Low molecular weight heparin
Vit. K + warfarin
Clot dissolves
plasminogenplasmin
Thrombolytics
Photo Source: Used courtesy of E. McCabe, RN, Santa Barbara City College
150
Anticoagulants Examples: Dalteparin, enoxaparin, heparin,
warfarin Indications: prevent and treat thromboembolic
disorders such as DVT, PE, and atrial fibrillation with embolization
Adverse effects: thrombocytopenia (with heparin) Androgens, chloral hydrate, chloramphenical,
metronidazone, quinidine, sulfonamides, thrombolytic drugs, and valproic acid increase the risk of bleeding and enhance the effects of coumadin
Alcohol, barbiturates, estrogen-containing oral contraceptives and foods high in Vitamin K increase risk of clotting and may decrease effect of heparin
151
Heparin
Accidentally discovered by medical student in 1916, used medically first time in 1935 on humans
High molecular weight – called unfractionated
Does not cross the blood brain barrier – can be used during pregnancy
Half life IV = 45 to 90 minutes Half life SQ = 60 to 120 minutes Bioavailabity is about 20 to 30 %
152
Heparin
Destroyed by enzymes in the GI tract
Administered IV or SQ – IM = muscular hematomas
Varying bioavailability Monitor with - aPTT (activated
partial thromboplastin time) = Preferred because more
sensitive to intrinsic pathway
153
Heparin
Most serious side effect is hemorrhage Administer protamine sulfate by slow IV infusion
to neutralize heparin Drug-drug interactions: antiplatelet drugs,
NSAIDs oral anticoagulants, nitroglycerin, cephalosporins, penicillins, salicylates all may affect of heparin
Uses: Hemodialysis, open-heart surgery, prevention of thromboembolism, post MI, inhibits platelets from binding, DVT, PE, atrial fib, stroke prevention a.k.a. acute brain attack or CVA
Highly protein bound = variable anticoagulation b/c the ill have reactive proteins that also bind to heparin.
154
Anticoagulants
Nursing Responsibilities Heparin given initially because of its
rapid action, then switch to coumadin over several days until therapeutic level is reached
Heparin affects PTT and coumadin PT Inject SQ in abdomen and do not
aspirate or rub at injection site Protamine sulfate antidote for heparin Vitamin K antidote for coumadin Soft toothbrush and electric razor
155
Anticoagulants Monitoring heparin therapy
Obtain baseline PTT Administer a bolus dose of heparin IV,
as ordered Follow with continuous infusion as
ordered Obtain follow up PTT at specified
Values> 1 ½ time the controlContinue to monitorAssess for S/S of bleeding
Values < 1 ½ time the controlContact MDAnticipate dosage increase Increase dosage as ordered
156
Low molecular wt. Heparinexample enoxaparin (Lovenox)
Given by SQ injection Mainly Acts on factor X to begin
the coagulation cascade to inhibit the conversion of prothrombin to thrombin. Produces greater prothrombin effect than binding to factor II as Heparin does.
Also called fractionated heparin
157
Low Molecular wt. Heparin
T.I.A.s Ischemic symptoms Unstable angina Atherosclerosis Non ST elevation M.I. a.k.a, Q wave
M.I. (without elevated enzymes - homocystine)
ST elevations a.k.a. acute M.I. (with elevated enzymes- homocystine)
158
Low molecular wt. Heparin
High bioavailability and so more predictable than heparin because binds to factor X
No routine testing required Can be administered at home Bleeding is main adverse effect Usually weaned off and when
stable onto warfarin (Coumadin)
159
Oral anticoagulantWarfarin (Coumadin)
AKA “rat poison” May also be given IV, but rarely is Bound tightly to plasma protein –
other drugs can displace + other proteins may be present during tissue breakdown (example C- reactive protein)
Very difficult to monitor PT (prothrombin time) and dosed by INR (international normalized ratio)
Long half- life 1 to 3 days
160
Warfarin (Coumadin)
Variable dosing and unpredictable; MUST COME IN FOR FREQUENT MONITORING.
Used prophylaxis for deep vein thrombosis (DVT), Pulmonary Embolus (PE), atrial fibrillation, off label for recurrent Transient Ischemic Attack (TIA), recurrent Myocardial Infarction (MI)
Suppresses coagulation activity by interfering with the production of vitamin K-dependent clotting factors in the liver.
Reduced amount of available Vitamin K for clotting factors II, VII, IX and X
161
Warfarin (Coumadin)
Humans can not synthesize Vitamin K, but bacteria in GI tract can
Treat excessive bleeding with Vitamin K Watch for bruising Careful in older adult because MANY drug
interactions and fall can cause excessive bleeding
Used to prevent clot formation in conditions such as atrial fib, not acute situations
IV Heparin to PO warfarin administer the 2 drugs simultaneously for 2 to 3 days to ensure continuous therapeutic anticoagulation
162
Antiplatelets
Clopidogel (Plavix) & ticlopidine (Ticlid) bind to ADP (adenosine dephosphate) which inhibits its effect on platelets (60 – 70% )
Aspirin inhibits thromboxane (TX2) in Arachidonic Acid Pathway (30-40%)
Abciximab (ReoPro) binds to the GP IIb/IIIa receptor and inhibits platelet aggregation (90%)
Tirofiban (Aggrastat) {new}
163
Antiplatelet Drugs Drug examples:
Aspirin, dipyridamole (persantine), Ticlopidine (Ticlid)
Indications for use: Prophylaxis for thrombo-embolic events Ticlid – second line drug use to prevent stroke in
high risk individuals, decrease intermittent claudication, and decrease graft occlusion after coronary artery bypass
Contraindications: Active bleeding, thrombocytopenia, severe liver
impairment Adverse effects: Bleeding, tinnitus, dizziness,
neutropenia (Ticlid)
164
Thrombolytic Drugs Drug examples:
Alteplase (tissue plasminogen activator) (activase), streptokinase, urokinase
Indications for use: Drugs used to lysis coronary artery
thrombi Alteplase, streptokinase, and urokinase
used to treat PE Streptokinase and urokinase used to
treat DVT and to clear arterial catheters and arteriovenous shunt
MRI needed for CVA to determine cause
165
Thrombolytic Drugs
Contraindications: Recent streptococcal infection, active internal bleeding
Adverse effects: urticaria, fever Nursing responsibilities:
Monitor V/S for bleeding or hypotension, check peripheral pulses to ensure circulation
Keep typed and cross matched blood on hand to administer in case of hemorrhage
Thrombolytic drugs should be administered only when the patient’s hematologic function and clinical response can be monitored
Ensure that aminocaproic acid (Amicar), the antidote for thrombolytic overdose, is readily available
166
Antiplatelet Drugs
Drug examples: Aspirin, dipyridamole (persantine),
Ticlopidine (Ticlid) Indications for use:
Prophylaxis for thrombo-embolic events Ticlid – second line drug use to prevent
stroke in high risk individuals, decrease intermittent claudication, and decrease graft occlusion after coronary artery bypass
Contraindications: Active bleeding, thrombocytopenia, severe
liver impairment Adverse effects: Bleeding, tinnitus, dizzines,
neutropenia (ticlid)
167
Drugs Affecting the Endocrine System
168
Thyroid Hormones
Thyroid replacement increases metabolism, cardiac output, regulates cell growth and causes diuresis. Most commonly used: – thyroid and
levothyroxine (Synthroid) Contraindications: – Recent MI, adrenal
insufficiency, hyperthyroidism Side Effects: – Cardiac dysrhythmias Adverse Effects: – Tachycardia, angina,
hypertension, insomnia, headache, anxiety, increased or decreased appetite, menstrual irregularities, weight loss, heat intolerance (“hot flashes”) and thyroid storm
169
Antithyroid Drugs Used to treat hyperthyroidism
Most commonly used: – methimazole and propylthiouracil which inhibit formation of thyroid hormone
Contraindication: – Drug allergy, avoid in pregnancy if at all possible
Side Effects: – Drowsiness, smoky colored urine, aching
Adverse Effects: – Increased BUN and creatinine, enlarged thyroid, liver and bone marrow toxicity
Interactions:– Increase in activity of anticoagulants
Propranolol (Inderal) (non-selective beta blocker) given to control symptoms before antithyroid drugs work 2-3 weeks
170
Insulin
Replaces insulin not made or made defectively in the body. Indicated primarily for Type I diabetes but
may be used with Type II Requires careful dosing regimen Contraindications: – Drug allergy to
specific product. Adverse Effect: – Hypoglycemia from
overdose, weight gain Interactions: – corticosteroids,
epinephrine, furosemide, phenytoin, thiazides, thyroid hormones, alcohol, anabolic steroids, MAO inhibitors
171
Action of Insulins
Preparation Onset of Action
Peak Action Duration of Action
Humalog
10-15 minutes
30-60 minutes 5 hours or
less
Regular* 30-60 min 2-4 hrs 6-10 hrs
NPH/Lente
1-2 hrs 4-8 hrs 10-18 hrs
Ultralente
2-4 hrs 8-14 hrs 18-24 hrsInsulin glargine (Lantus) - a basal insulin for tighter glycemic control. Do not mix with insulin. May be
used also for type 2 glycemic control.
Regular insulin can be given IV in emergency situations
172
Sliding Scale (Rainbow Coverage)
Regular insulin is given according to blood glucose results. Used mostly with newly diagnosed diabetics
when stress occurs, such as illnesses requiring hospitalization and surgery
Used with blood glucose greater than 200 mg/dl
Example: 4 units = 200 – 250 6 units = 251 – 300 8 units = Greater than 300
May need to call MD – Carefully check order.
173
Classes of agents for Type 2
SULFONYLUREAS 1ST generation 2nd generation
ALPHA-GLUCOSIDASE INHIBITORS BIGUANIDES MEGLITINDES THIAZOLIDINEDIONES INCRETIN MIMETICS (injected, new for
type 2) SYNTHETIC ANALOGS OF AMYLIN
(injected, new (1 & 2) Insulin glargine for tighter control (1 & 2) Inhaled insulin (1 & 2) “EXTRA, EXTRA!
Two new
classes!”
174
Complications of uncontrolled Type 2
Vascular disease especially hypertension
Urinary Tract Infections (UTIs) Vaginitis Prostatitis Retinopathy Nephropathy Nonketotic coma (uncontrolled)
175
Sulfonylureas (secretagogues)- means stimulates the secretion of insulin
First generation EXAMPLE=Diabinese
(chlorpropamide) Potentiated by NSAIDs Highly protein bound P450 system so drug
interactions Hypoglycemia Stimulates pancreas May increase incidence
of increased glucose intolerance
Rarely used today
Second generation EXAMPLE=
Diabeta (glyburide)
Much the same as 1st generation
May increase insulin sensitivity
Also potential hypoglycemia
176
Biguanides
EXAMPLES Metformin (Glucophage XR) & Metformin (Fortamet XR)
Action Decrease hepatic glucose production Increases insulin sensitivity Decreases intestinal absorption of glucose
Improves lipid profile, decreases Triglycerides
DOES NOT produce hypoglycemia Used as monotherapy or combination
therapy
177
Biguanides
New use as prevention of Type II with FBS < 110 mg/dL > 125 mg/dL & History in family
May lower vitamin B12 levels ? Best to supplement
Side effects: Usually good side effect profile, GI symptoms, WEIGHT REDUCTIONDo not give to patients who are being treated for CHF because of possibility of lactic-acidosis
178
Alpha-Glucosidase Inhibitors
EXAMPLES Acarbose (Pecose) Miglitol (Glyset)
Action: Blocks intestinal amylase so delays
breakdown of complex carbohydrates Decreases postprandial glucose
Monotherapy or combination therapy Side effects: are minimal - flatulence,
diarrhea, abdominal cramps
179
Thiazolidinediones
EXAMPLES Pioglitazone (Actos) Rosiglitazone (Avandia)
Action: Reduce insulin resistance Monotherapy or combination with
sulfonylureas, metformin Enhance insulin action in skeletal
muscle, liver and fat tissue Reduce hepatic glucose output Glucose uptake into peripheral
tissue
180
Thiazolidinediones Precautions:
Do not use in patients with hepatic dysfunction
Monitor liver function tests Caution with cardiac patients In combination with other antidiabetic
agents, can cause fluid retention, may exacerbate CHF; caution with insulin use
Side effects: May cause edema and weight gain,
headache, upper respiratory infection Does not cause hypoglycemia when
used as monotherapy
181
Meglitinides (partial secretagogues)
EXAMPLES Repaglidine (Prandin) Taken ½ hour before meals Rapidly absorbed Needs presence of glucose to exert it’s
action Stimulates release of insulin
Side effects: Potential for hypoglycemia, URI
Monotherapy or combination with metformin
182
Amino Acid Derivative a secretagogue
EXAMPLE Naeglinide (Starlix)
Give adjunct with diet & exercise Give to those who have not been treated
chronically with other antidiabetic agents
Take 1 hr. to 30 min. before meals Caution if patient is malnourished Skip dose if meal skipped Contraindicated in Type I and
ketoacidosis Not recommended in pregnancy Monitor when concurrent highly
protein-bound drug given
183
184
Parathyroid hormone (PTH)
Stimulated by low serum calcium Inhibited by normal or high levels of
calcium via negative feedback system Phosphate also regulated by PTH via
an inverse relationship with calcium PTH activates Vitamin D which
increases intestinal absorption Less urinary excretion of calcium Bone reabsorption of calcium from
bone
185
Calcitonin & decreased PTH
Hypercalcemia decreases secretion of PTH
Calcitonin is synthesized in the thyroid Calcium is lost in urine Decreased absorption of calcium from
the intestine Decreased reabsorption of calcium from
bone
186
Vitamin D
In activated form acts like hormone (intermediate metabolism in liver then to active form in kidney called calcitriol)
Obtained from foods and by sunlight on skin
Deficiency limits amount of calcium absorbed from diet
Causes release of calcium from the bone (reabsorption)
Causes G.I. absorption of calcium Decreased levels caused by medications
including tetracyclines and Dilantin
187
Osteoporosis
Risk factors Current low bone mass (DXA) [dual
energy x-ray absorptiometry] Thin, small frame female Advancing age Family history of osteoporosis Estrogen/testosterone deficiency Anorexia nervosa Low lifetime calcium intake History of fracture after age 50 Smoking, alcohol and sedentary life style Use of oral glucocorticoids for chronic
disease
188
Drugs used for Calcium/bone Disorders (osteoporosis & osteopenia)
Biphosphonates: alendronate (Fosamax), risedronate (Actonel) new once a month ibandronate (Boniva) used for osteopenia, osteoporosis, Paget’s disease
Action: undergo incorporation into bone. Osteoclasts begin to reabsorb biphosphonate-containing bone so they ingest some of the drug, which then acts to inhibit their activity
All poorly absorbed from GI tract. Take in a.m. with full glass of water, but
without food for 30 minutes and remain in upright position to minimize risk of esophagitis.
189
Drugs used for Calcium/bone Disorders (osteoporosis & osteopenia)
Thyroid hormone: Calcitonin (Miacalcin)
•Produced by body when low levels of calcium
•Used to treat osteopenia
•Nasal spray
•Suppresses bone reabsorption
•Main side effect is runny nose and sneezing
•Hormone Replacement Therapy
190
Mechanisms that raise serum calcium levels
If decreased Serum Calcium
Parathyroid hormone secretion
renal excretion of calcium
Intestinal absorption of calcium via activation of Vit D
Bone resorption so calcium
191
Mechanisms that lower serum calcium levels
If increased Serum calcium
Parathyroid hormone secretion
Calcitonin secretion
Renal excretion of calcium
Intestinal absorption of calcium
Bone resorption
Serum calcium
192
Arthritis
Osteoarthritis
Rheummatoid arthritis (RA)
Acute gouty arthritis
Excessive wear & tear of wt. bearing joints
Autoimmune disorder with autoantibodies (rheumatoid factors)
Uric acid crystals accumulate in joints
Often thought as normal part of aging process
Systemic manifestations
Sudden onset, triggered by diet, injury/stress; often big toe
193
Corticosteroids There are 2 types – Glucocorticoids
and Mineralcorticoids Cortisol is primary glucocorticoid Aldosterone is primary mineralcorticoid
Some Indications: Replacement therapy for Addison’s
Disease Inflammatory diseases
Arthritis Ulcerative Colitis Nephrotic syndrome Liver disorders Ocular inflammations
194
Corticosteroids (cont’d)
o Some indications: (cont’d)o Allergic conditions – status
asthmaticus, asthma, allergic reactions
o Neoplastic diseaseso Brain-injuries (cerebral edema)o Skin conditions (psoriasis/dermatitis)o Collagen disease (Lupus)o Ophthalmic – conjunctivitis, corneal
abrasionso Asthma
195
Corticosteroids (cont’d)
Precautions: Therapy is tapered and not discontinued
abruptly Vaccinations are contraindicated Use with caution during pregnancy, lactation,
clients high risk for infections, peptic ulcer disease (PUD), cardiac or renal failure, diabetes, myasthenia gravis
Do not use with fungal or viral eye infections Interactions – Increased risk of:
Hypokalemia with K-depleting diuretics Digitalis toxicity Gastric ulcers with NSAIDS Hyperglycemia
196
Estrogen Indications:
Hormone replacement therapy Normal sexual development with estrogen
deficiency Androgen suppression with prostate Ca Oral contraception by inhibiting ovulation
Side Effects: Headache Depression
Adverse Effects: Hypertension Thrombo-embolic disorders Abnormal uterine bleeding Unopposed may lead to endometrial cancer
197
Estrogen (cont’d)
Contraindications: Pregnancy and lactation Previous or active thrombo-phlebitis or
embolic disorders Estrogen-dependent Cancers History of CVA or Coronary Artery Disease
(CAD), Breast Cancer, liver disorders Precautions:
Oral contraceptives by diabetics or smokers Interactions: Some anti-convulsants
decrease the effectives of oral contraceptives due to P450 system
198
Progentins(not progesterone)
Indications - Oral contraception with estrogen, HRT, endometriosis, dysmenorrhea, uterine bleeding
Adverse Effects: Breakthrough bleeding Impaired glucose tolerance Depression Edema and weight gain
Contraindications: Pregnancy, undiagnosed vaginal
bleeding, Thrombo- phlebitic or embolic disorders, Ca of reproductive organs
199
Androgens
Most important is testosterone Uses:
Males – erectile dysfunction, delayed puberty, muscle wasting in AIDS
Females – Endometriosis, fibrocystic breast changes, some menopausal symptoms, advanced breast cancer
Females – increases libido
Adverse Effects: Virilization, hepatotoxicity, edema,
gynecomastia in males
200
Androgens (cont’d )
Precautions: Contraindicated in pregnancy and
prostate enlargement Children must have bone growth
evaluated q 6 months Anabolic Steroids – Schedule III
controlled substance (not same as testosterone)
Testosterone Interactions:
Enhance effects of oral anticoagulants, oral hypoglycemics and insulin
Barbiturates and calcitonin interfere with the effects of androgens
201
Drugs Affecting the Respiratory System
Photo Source: National Cancer Society, Public Domain, http://visualsonline.cancer.gov/details.cfm?imageid=1775
202
Antihistamines
Indications: Various allergic reactions Induce sleep Relieve nausea Prevent motion sickness
Side Effects: Drowsiness Dry mouth and blurred vision
Elderly are at high risk for dizziness, confusion, hypotension, unsteady gait & CNS stimulation - Lower doses due to anticholinergic effects
203
Antihistamines (cont’d)
Adverse Reactions: Headache, hypertension, GI distress Drug allergy – anaphylaxis Excessive sedation with other CNS depressants
Contraindications: Narrow angle glaucoma, prostatic hypertrophy,
pregnancy, bladder neck obstruction, PUD Not recommended in bronchitis or pneumonia
because they dry secretions making it difficult for removal.
Interactions: Some antibiotics enhance effects MAOIs inhibit metabolism thus enhancing
effects
204
Mode of Action Antitussives
narcotic antitussives directly suppress cough reflex inmedulla of the brain (CNS)
dextromethorphan same mode of action as narcotic
benzonatate anesthetizes ornumbs the cough reflex
Photo Source: Wikimedia Commons, Creative Commons, http://commons.wikimedia.org/wiki/Image:Brain_bulbar_region.svg
205
Antitussives
Used to relieve coughs: suppresses cough center in medulla if centrally acting Antitussives containing codeine are
Schedule IV meds. Dextromethorphan, non-opioid
Side Effects for centrally acting: Drowsiness, sedation, dizziness,
restlessness, agitation, euphoria Adverse Effects:
Respiratory depression – antidote opioid toxicity (Narcan)
Hypotension, Tachy or bradycardia Drug allergy - Anaphylaxis
206
Drugs Affecting the Respiratory System
Beta-Agonists inhaled - short acting + long acting
Beta-agonists – oral agents Methylxanthines Anticholinergics Antiasthmatics
[cromolyn & nedocromil] Corticosteroids Leukotriene modifiers
207
Bronchodilators Used to relax smooth muscles in
bronchi and bronchioles for asthma, bronchitis, emphysema
3 Types of Drugs Adrenergics(beta -2) Xanthines Anticholinergics (given by inhalation)
208
Follow step approach guidelines when doing health teaching.
See health care provider at least every 6 months for evaluation.
Identify and list triggers. Keep asthma diary & record
“personal best” from peakflow meter. Record three times a day.
Contact provider if peak flow drops and go to
established plan.
209
Step Approach Terms
Step oneMild Intermittent
Step TwoMild Persistent
Step ThreeModerate Persistent
Step FourSevere Persistent
210
Beta-AgonistsRescue drugs (short acting)
Used most often During acute phase of asthmatic
attack For COPD acute attack of SOB Quickly reduce airway constriction Are Sympathomimetics Stimulate beta-2 receptors
211
Anticholinergics
Corticosteroids
Indirect-acting Agents
212
Anticholinergics Controller drugs
Ipratropium bromide = Atrovent
New powder inhaler (not metered dose inhaler) 24 hr. duration & may be superior to atrovent = tiotropium bromide (Spiriva)
NOT for acute attacks!
For maintenance tx of bronchospasms MAINSTAY FOR COPD (when combined
with atrovent is called Combvient – brand name)
213
Side Effects of Anticholinergics
Respiratory: Dry mouth or throat and coughing
Gastrointestinal: GI distress
CNS: Headache & anxiety
Mild anticholinergic effects if inhaled – do not use if patient has glaucoma or BPHAtrovent or Combivent inhalers produce serious allergic reactions to those with peanut allergy
214
Xanthine BronchodilatorsController agent
Aminophylline *usually I.V. when patient in distress
Theophylline *[examples]aerolate, bronkodyl, elixophyllin,
slo-bid, theobid, theo-dur, theolair, & uniphyl
215
Theophylline
Wide variability as to plasma half-life Narrow therapeutic index Unpleasant side effects of anxiety, agitation,
insomnia, tachycardia, palpitations Need to draw blood samples to stabilize
patient on correct dosage to minimize adverse effects
Older adults with liver disease and CHF with pulmonary edema have prolonged half-life
Smokers and children have shorter half-life
216
Antibiotic classes:Sulfonamides, Penicillins,
Cephalosporins, Macrolides,Quinolones, Aminoglycosides,
Tetracyclines, GlycycyclinesCarbapenems,
Monobactams, Oxazolidinones Streptogramins, Ketolides &
Glycylcyclines
217
Drugs Used to Treat Infections
Drugs for treating infections are referred to as antibiotics (most common term) or anti-infectives, antimicrobial
Antibiotics are not effective against viruses
Resistance is the BIG PROBLEM
218
Anti-infectives General Action
Types of antibiotic
action
Damages the cell
wall
Modifies
protein synthe
sis
Modifies
DNA synthe
sis
Modifies energy
metabolism via
folic acid
219
AntibioticsActions
Inhibit the growth of bacteria Inhibit cell wall synthesis Are bacteriostatitic and bacteriocidal
Adverse Reactions: Some are very nephrotoxic Hearing impairment- ototoxic Superinfections May potentiate decreased effectiveness of other medications (Be aware of specific interactions with specific drugs) “Sunburn” reaction – Avoid direct sunlight with tetracyclines
Contraindications: Known drug allergy Many should not be used during pregnancy
Many resistance patterns
220
Penicillin resistance
Penicillinases (enzymes) produced by bacteria that destroy penicillin by cleaving the beta-lactam ring of the drug
Clavulanic acid enhances the activity of penicillins. Binds to the active sites of penicillinases rendering the enzyme inactive
221
Some Commonly Used Antibiotics
Sulfonamides One of the first anti-infectives Often used today for Urinary Tract
Infections Drink fluids to prevent urinary crystals
Septra Bactrim
Assess allergy to other sulfa medications (Sulfonylureas,Thiazide diuretics)
Penicillins Penicillin G, Ampicillin, Amoxicillin Observe for clostridium difficule Fruit juices can inactivate the drug Assess electrolytes
222
Some Commonly Used Antibiotics (cont’d)
Tetracyclines (not with milk, CA products)
Take one hour before or two hours after meal Causes brown teeth in children! Photosensitivity
Macrolides – Erythromycin and Biaxin can have many drug interactions, problems with G.I. distress
Used to treat mycoplasma (penicillins & cephalosporins not effective!)
Used when patient is allergic to penicillin Use cautiously with heart, renal, liver disease Not given with fruit juice
223
Cephalosporins
•Similar to PCN but broader spectrum
•Differ as to generation for coverage. When anaphylaxic reaction to PCN, should not be given a cephalosporin
•A beta-Lactam antibiotic
•May be ineffective against bacteria that produce
enzyme beta-lactamase
•Called cephalosporinase
•Avoid alcohol. Also, now may not be effective against MRSA
224
Quinolones
Kill bacteria = bactericidal Active on a wide variety of bacteria
gm- & gm+ as well as a-typical infections Excellent oral absorption Antacids reduce their absorption * gm- coverage & excellent [drug] for
kidneys Great for treating UTI’s & prostatitis first
oral class of antibiotic to kill gram- bugs Good for Salmonella typhi and Shigella Not used in children. May damage
cartilage, leading to deformities in gait
225
Quinolones
Used to treat: lower respiratory tract infections bone & joint infections infectious diarrhea urinary tract infections skin infections
Overuse! They should be reserved for serious infections and resistant strains. MRSA can be susceptible. Do not want to create resistance
Should not be used in children - may damage cartilage leading to deformities in gait
226
Aminoglycosides
Used to Treat:Pneumonias, resistant UTIs, septicemia, CNS infections – serious & life threatening
Action:Bind to 30S & 50S ribosomal subunitsCause inhibition of protein synthesis
Precautions:Nephrotoxicity & ototoxicity (8th cranial nerve) Drug levels help prevent high peaks & troughs, many drug interactions; must monitor carefully.
227
Miscellaneous antibiotics
Vancomycin Rapidly bactericidal so low resistance Glycopeptide antibiotic not related to PCNs Given by intermittent IV infusion Used in life-threatening staph or strep
infections and MRSA Adverse reactions are nausea, flushing and
itching Red Man Syndrome
Toxic reactions: tinnitus, hearing loss, nephrotoxicity
Often given with piperacillin (Zosyn) IV a broad spectrum PCN + B-lactamace inhibitor for MRSA
228
Ethambutol (Myambutol) RARE retrobulbar neuritis & blindness GI upset
INH isoniazid (Nydrazid) Peripheral neuritis & rarely
hepatotoxicity Don’t give for prophylaxis after age 40 because of increase in side effects Peripheral neuropathy Selegiline (SEL)-like syndrome
Pyrazinamide Hepatotoxicity & hyperuricemia (reports of liver failure)
Rifampin Hepatitis, body fluids turn orange/red color
Streptomycin
Antituberculars
229
Latent TB
If skin test is positive Follow up with chest x-ray
Use INH for 9 months or rifampin for 4 months for latent TB
230
Antifungal Agents = drug interactions + liver toxicity
Itaconazole (Sporanox): inhibitor of cytochrome 3A4 = increased statins, Ca + channel blockers, some Benzodiazipines, etc.
Ketoconazole (Nizoral): inhibitor of cytochrome 2C19 = increased levels of phenytonin, some Tricyclic Antidepressants, some Benzodiazipines, etc.
Fluconazole (Diflucan): inhibitor ofcytochrome 2C9 = increased level of celebrex, NSAIDs, Warfarin, phenytoin, etc.
Examples of systemic antifungals
231
Antivirals
Drugs used to kill viruses Inhibit their ability to replicateDifficult to kill because they live inside our
cells Utilize our cells to replicate
Any drug that kills a virus may kill our cellsOnly work during viral replicationMutations & resistance commonAntimicrobials not effective unless
accompanying secondary bacterial infection
232
Photo Acknowledgement:Unless noted otherwise, all photos
and clip art contained in this module were obtained from the
2003 Microsoft Office Clip Art Gallery.
Top Related