01 Concept of Medication Therapy
Transcript of 01 Concept of Medication Therapy
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Concept of Medication
Therapy
By
Arif Muttaqin, S. Kep, Ns, MMRS
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Drug Names
Chemical name Describes the drugs chemical composition and
molecular structure
Generic name(nonproprietary name) Name given by the United States AdoptedName Council
Trade name(proprietary name)
The drug has a registered trademark; use of the namerestricted by the drugs patent owner(usually the manufacturer)
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Drug Names (cont'd)
Chemical name (+/-)-2-(p-isobutylphenyl) propionic acid
Generic name ibuprofen
Trade name
Motrin, Advil
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Quality use of medicine
The quality use of medicines refers to the process of: selecting patient management options wisely
choosing suitable medicines if a medicine is considered necessary
using medicines safely and effectively.
This definition of quality use of medicine not only applies
to medicines in the general practice setting, but also toall medicines used by individual patients that can affecttheir health. This whole-health system view is necessaryas general practice patients obtain their medicationsfrom a range of sources such as those initiated by
themselves, other general practitioners, other medicalspecialists, pharmacists and complementary therapists.
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Pharmacokinetics
Pharmacokineticsis the way thebody acts on thedrug once it is
administered. It isthe measure ofthe rate (kinetics)of absorption,distribution,
metabolism andexcretion(ADME).
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Absorption
Absorption is the movement of a drug fromits site of administration into the blood.
Most drugs are absorbed by passive
absorption but some drugs need carriermediated transport.
Small molecules diffuse more rapidly than
large molecules. Lipid soluble nonionized drugs are absorbed faster.
Absorption is affected by blood flow, painstress etc.
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Absorption
Acidic drugs such as asprin will be better absorbed in the stomach whereas basic drug ikemorphine will be absorbed better in the intestine. Most of the absorption of the drug takes place inthe small intestine. Since the surface area of the stomach is much smaller than that of theintestine. Most of the drugs are absorbed in the small intestine since the amount of time that thedrugs spend in the stomach is less and also the surface area of the stomach is small. If a basicdrug is taken after a meal then the activity of the drug can be reduced whereas if an acidic drug istaken after a meal then the action of the can be noticed much more quickly, owing to the gastricabsorption.
For a drug even though lipophilic to be absorbed in the intestine some portion of it needs to bedissolved in the intestinal juices which are aqueous. There are some substances that are partlysoluble in water and it is these that will be absorbed and then an equivalent amount will beabsorbed from the undissolved portion. Thus complete absorption will take place. There are bilesalts present in the intestine which will aid in salvation of the drug and their resultant absorption.Drugs that are amphipathic have no problem in getting absorbed. There are some drugs that arecompletely insoluble in water such drugs float as globules in the intestine but the bile salts willemulsify these into small enough particles such that absorption can take place. E.g. vitamins.Some of the drugs are similar to compounds found in the body for e.g. thyroxine and such drugscan be absorbed into the system by active transport.
When drugs are injected into the muscle, subcutaneous layer absorption still has to take place butit is less dependent on the chemical nature of the drugs since the drugs are absorbed into thecirculatory system through the small pores in the capillary walls.
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Distribution
Distribution is the movement of drugs
throughout the body. Determined by the
blood flow to the tissues, it is ability of the
drug to enter the vasculature system andthe ability of the drug to enter the cell if
required.
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Plasma Protein Binding
The blood stream has the ability to transport relatively insoluble substances.
These substances are transferred by binding to the proteins which have avery amphipathic structure. The hydrophilic group renders the proteinsoluble in water and the lipophilic compounds are attracted to the lipophilicgroup and are loosely bound to the protein molecule hence protein bound.Most of the drugs travel in the plasma are partly in solution and partly boundto the plasma protein. The bound drug is inactive and the unbound drug is
active. The ratio of bound to the unbound drug varies. Binding is reversible.Generally acidic drugs bind to albumin and basic drugs to 1 acidglycoprotein. Diseased state can cause a problem on the effectiveness ofthe drug. As globin levels increase with age this factor should be taken intoaccount when treating an elderly person with a basic drug.
The protein bound drug is in equilibrium with the free drug. That means thatonce the free drug enters the target tissue then the protein bound drug willbe released to maintain equilibrium. If two drugs bind at the same site of theprotein and are administered together then there can be problems. e.g.Warfarin and asprin.. asprin displaces warfarin from its bound protein as aresult of which there are elevated levels of warfarin in the unbound stateand this can lead to warfarin toxicity.
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Tissue Distribution
After absorption most drugs are distributed
in the blood to the body tissue where they
have their effect. The degree to which the
drug is likely to accumulate in the tissue isdependent on the lipophilicity and local
blood flow to the tissue. Highly perfused
organs receive most of the drugs.
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The role of the liver in drug distribution
After the drug is absorbed by the GI tract, it is taken upby the part of the bloodstream called the hepatic portalsystem. Most of the drugs are absorbed into this systemexcept for the lipids which are absorbed into thelymphatic system and then delivered into the blood by
the thoracic duct into the superior vena cava. The hepatic portal system is designed to take digested
foodstuff into the liver where it can be processed, insome cases it is stored before being distributed and it ispossible that this may happen to the drug and the drug
would be metabolized before reaching the rest of thebody. Such drugs that metabolized by the liver are saidto have a high hepatic first pass. Hence drugs with avery high hepatic first pass cannot be given orally.
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The BloodBrain Barrier (BBB)
The capillaries in the CNS are different they have poreswhich are sealed by the connective tissue and henceonly small molecules can cross the blood brain barrierand the substances that can cross over have to be verylipophilic in nature. The blood-brain barrier (BBB) is the
protective mechanism of the CNS and is not presenteverywhere in the brain. This is sometimes useful as itavoids some drugs from crossing the CNS and causingdeleterious effects.
E.g. neuromuscular blocking agents. Sometimes the
blood brain barrier allows the transport of drugs resultingin unwanted effect for e.g. antihistamines cross the bbband result in drowsiness, now there are antihistaminesthat are made that are not so lipophilic in nature.
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Metabolism or Biotransformation
It is the process of transformation of a drug within the body to makeit more hydrophilic so that it can be excreted out from the body bythe kidneys. This needs to be done since drugs and chemicals areforeign substances in our body. If the drug continues to be in thelipohilic state and is going to be filtered by the glomerulus then it willbe reabsorbed and remain in the body for prolonged periods. Hence
metabolism deals with making the drug more hydrophilic such that itcan be excreted out from the body. In some cases the metabolitescan be more active than the drug itself e.g. anxiolyticbenzodiazepines.
Some enzymes are highly specific and will breakdown onlycompounds that they recognize for e.g. glucose dehydrogenase. But
there are some enzymes such as pepsin which are not specific andwill breakdown most soluble proteins into smaller polypeptides oramino acids. This enzyme and many other proteolytic enzymesattack the peptide bond that joins the amino acids to make proteins,and in this way break the protein down.
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Two types of enzymes are involved in metabolism:
Phase I Metabolism These enzymes modify the drug chemically by processes such as
oxidation, reduction and hydrolysis or by the removal and addition of anactive group.
Phase II Metabo lism These include the conjugation of a drug or a phase I metabolite with a
polar group to render it possible for excretion. e.g. sulphates andglucuronide
The deconjugation of the drug by bacterial enzymes is called theenterohepatic cycle. Sometimes this deconjugation can lead toincreased levels of drugs in the body. But some times due to
treatment with antibiotics there may be less or no deconjugation asa result of which there will be less drug in the body.
Principal sites of metabolism are Liver and Kidney and once thedrug is rendered hydrophilic they can be easily excreted out by thebile and urine without significant reabsorption.
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Enzyme
Enzyme Induction
There are some drugs that can lead to an increase in
the production of the enzyme and as a result speed
up the metabolism of the drug and hence a higherdose of the drug is required to achieve the therapeutic
effect.
Enzyme Inhibition
Some drugs result in the inhibition of certain enzymesand as a result there is an accumulation of the drug in
the body and can lead to drug toxicity. This is also a
form of drugdrug interaction.
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Excretion
Excretion is the removal of the substance fromthe body.
Some drugs are either excreted out unchangedor some are excreted out as metabolites in urine
or bile. Drugs may also leave the body bynatural routes such as tears, sweat, breath andsaliva.
Patients with kidney or liver problem can have
elevated levels of drug in the system and it maybe necessary to monitor the dose of the drugappropriately since a high dose in the blood canlead to drug
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1. You are caring for a client who has diabetes complicated bykidney disease. You will need to make a detailed assessmentwhen administering medications because this client mayexperience problems with:
A. Absorption
B. Biotransformation
C. Distribution
D. Excretion
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Pharmacodynamics
Study of the mechanism of drug actions in
living tissue
Drug-induced alterations to normal
physiologic function
Positive change-Therapeutic effect-Goal of
therapy
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Mechanism of Action
Ways in which a drug can produce atherapeutic effect
The effects that a particular drug has
depends on the cells or organ targeted bythe drug
Once the drug hits its site of action it canmodify the rate at which a cell or tissue
functions
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Mechanism of Action
Receptor Interaction
Enzyme Interaction
Non-Specific Interaction
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Receptor Interaction
Drug structure is essential
Involves the selective joining of drugmolecule with a reactive site on the cell
surface that elicits a biological effect Receptor is the reactive site on a cell or
tissue
Once the substance binds to and interactswith the receptor, a pharmacologicresponse is produced
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Receptor Interaction
Affinity- degree to which a drug binds with areceptor
The drug with the best fit or affinity will elicit thebest response
Drug can mimic bodys endogenous substancesthat normally bind to receptor site
Drugs that bind to receptors interact withreceptors in different ways to either block or elicit
a response
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Enzyme Interaction
Enzymes are substances that catalyze nearlyevery biochemical reaction in a cell
Drugs can interact with enzyme systems to alter
a response Inhibits action of enzymes-enzyme is fooledinto binding to drug instead of target cell
Protects target cell from enzymes action (ACE
Inhibitors)
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Non-Specific Interaction
Not involving a receptor site or alteration inenzyme function
Main site of action is cell membrane or cellular
process Drugs will physically interfere or chemically altercell process
Final product is altered causing defect or cell
death Cancer drugs, Antibiotics
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The nurse is giving a medication that has a
high first-pass effect. The physician has
changed the route from IV to PO. The nurseexpects the oral dose to be:
1. Higher because of the first-pass effect.
2. Lower because of the first-pass effect.
3. The same as the IV dose.
4. Unchanged.
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Therapeutic Effect
The expected or predictable physiologicalresponse a medication causes
A single med can have several therapeutic
effects (Aspirin) It is important for the nurse to know why
med is being prescribed
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Side Effects
Unintended secondary effects a medication
predictably will cause
May be harmless or serious
If side effects are serious enough to negate thebeneficial effect of meds therapeutic action, it
may be D/Cd
People may stop taking medications because ofthe side effects
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Adverse Effects
Undesirable response of a medication
Unexpected effects of drug not related totherapeutic effect
Must be reported to FDA Can be a side effect or a harmful effect
Can be categorized as pharmacologic,idiosyncratic, hypersensitivity, or drug interaction
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Adverse Effects
Adverse Drug Events
Adverse Drug Reactions (ADR)
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Toxic Effect
May develop after prolonged intake or when a
med accumulates in the blood because of
impaired metabolism or excretion, or excessive
amount taken Toxic levels of opioids can cause
resp.depression
Antidotes available to reverse effects
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Idiosyncratic Reactions
Unpredictable effects-overreacts or under reacts
to a medication or has a reaction different from
normal
Genetically determined abnormal response Idiosyncratic drug reactions are usually caused
by abnormal levels of drug-metabolizing
enzymes (deficiency or overabundance)
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Allergic Reaction
Unpredictable response to a medication
Makes up greater than 10% of all medicationreactions
Client may become sensitized immunologicallyto the initial dose, repeated administrationcauses an allergic response to the med,chemical preservative or a metabolite
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Allergic Reaction
Medication acts as an antigen triggering therelease of the bodys antibodies
May be mild or severe
Among the different classes of meds, antibioticscause the highest incidence of allergic reaction
Severe reaction-Anaphylactic reaction
Mild reaction-hives, rash, pruritis
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Other Drug Reactions
Teratogenic-Structural effect in unborn
fetus (thalidomide)
Carcinogenic-Causes cancer
Mutagenic- Changes genetic composition
(radiation, chemicals)
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Drug Interactions
Occurs when one med modifies the actionof another
Common in people taking several
medications at once One med may potentiate or diminish theaction of another or alter the way it isabsorbed, metabolized or eliminated
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Iatrogenic Responses
Unintentional adverse effects that occur duringtherapy
Treatment-Induced Dermatologic-rash, hives,acne
Renal Damage-Aminoglycoside antibiotics,NSAIDS, contrast medium
Blood Dyscrasias- Destruction of blood cells(Chemotherapy)
Hepatic Toxicity-Elevated liver enzymes(hepatitis-like symptoms)
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Synergistic Effect
Effect of 2 meds combined is greater than themeds given separately
Alcohol & Antihistamines, antidepressants,barbiturates, narcotics
Not always undesirable, physician may combinemeds to create an interaction that will havebeneficial effects (Vasodilators & diuretics tocontrol high BP)
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Medication Dose Responses
Serum Half-Life:Time it takes for excretionprocesses to lower the serum medicationconcentration by
Regular fixed doses must be given to maintaintherapeutic concentration
Dosage schedules set by institutions (TID, q8h,HS, AC, STAT, PRN)
Peak & Trough levels Therapeutic drug monitoring
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Half-life
The time it takes for one half of the original
amount of a drug in the body to be removed
A measure of the rate at which drugs are
removed from the body
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Pharmacotherapeutics:
Types of Therapies Acute therapy
Maintenance therapy Supplemental therapy
Palliative therapy
Supportive therapy
Prophylactic therapy
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Monitoring
The effectiveness of the drug therapy must
be evaluated
One must be familiar with the drugs:
Intended therapeutic action (beneficial)
Unintended but potential side effects
(predictable, adverse reactions)
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Monitoring (cont'd)
Therapeutic indexThe ratio between a drugs therapeutic benefits and its toxiceffects
Interactions may occur with other drugs or food Drug interactions: the alteration of action of
a drug by:
Other prescribed drugs
Over-the-counter medications
Herbal therapies
Drug interactionsAdditive effect
Synergistic effectAntagonistic effect
Incompatibility
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Monitoring (cont'd)
Medication misadventures
Adverse drug events
Adverse drug reactions
Medication errors
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Monitoring (cont'd)
Some adverse drug reactions are
classified as side effects
Expected, well-known reactions that result in
little or no change in patient management
Predictable frequency
The effects intensity and occurrence are related
to the size of the dose
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Adverse Drug Reaction
An adverse outcome of drug therapy in
which a patient is harmed in some way
Pharmacologic reactions
Idiosyncratic reactions
Hypersensitivity reactions
Drug interactions
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Toxicology
The study of poisons and unwanted
responses to therapeutic agents
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Table 2-9 Common
Poisons and Antidotes
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2. A postoperative client is receiving morphine sulfate via aPCA. The nurse assesses that the clients respirations aredepressed. The effects of the morphine sulfate can be classifiedas:
A. Allergic
B. Idiosyncratic C. Therapeutic
D. Toxic
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Fi t P Eff t
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First-Pass Effect The metabolism of a
drug and its passagefrom the liver into thecirculation A drug given via the
oral route may be
extensivelymetabolized by theliver before reachingthe systemiccirculation (high first-pass effect)
The same druggivenIVbypasses the liver,preventing the first-pass effect from takingplace, and more drugreaches the circulation
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Routes of drug administration Enteral route
Parenteral route
Inhalation
Topical
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Enteral Route:
Enteral route is through the alimentary canal.
It might be:
Oral
Sublingual Per rectum
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Oral Route: Oral route is the most common route of drug administration. It is mostly
used for the neutral drugs. It may be in the form of tablets, capsules, syrup,emulsions or powders.
Advantages: It is convenient
It is the cheapest available route
It is easy to use
It is safe and acceptable.
Disadvantages: Less amount of drugreaches the target tissue. Some of the drugis destroyed by gastric juices e.g. adrenaline, insulin, oxytocin
Absorptionhas to take place which is slow, so is not preferred during emergency.
It might cause gastric irritation
It might be objectionable in taste.
It might cause discoloration of teeth e.g. iron causes staining, tetracyclines below 14cause brown discoloration so are not advisable during pregnancy.
First Pass Effect: First pass effect is the term used for hepatic metabolism
of drugwhen absorbedand delivered through portal blood. Greater the firstpass effect, less amounts of the drug reach the systemic circulation.
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Sublingual Route:
Sublingual route involves tablets placed under the tongue orbetween cheeks or Gingiva. The drugshould be lipid soluble andsmall.
Advantages: Rapid absorptiontakes place.
Drugis dissolved easily
Drugenters the blood directly Less first pass effect.
Spitting out of the drugremoves its effect
Disadvantages: This method is inconvenient.
Irritation of the mucous membrane might occur
Person may swallow the drug
Might be unpleasant in taste.
Examples of drugsgiven by this route include nitroglycerin,isoprenaline and oxytocin. Nifedipine used for the treatment ofhypertension in emergency is given by sublingual route.
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Rectal Route:
Drugsin solid forms such as suppositories or in liquidforms such as enema are given by this route. This routeis mostly used in old patients. Drugsmay have local orsystemic actions after absorption.
Advantages: This route is preferred in unconscious or uncooperative patients.
This route avoids nausea or vomiting Drug cannot be destroyed by enzymes.
This route is preferred if drugis irritant.
Disadvantages: This route is generally not acceptable by the patients.
Locally acting drugs include glycerin and Bisacodyl suppository Systemic acting drugs include Indomethacin (anti inflammatory) and
aminophyllin (bronchodilator)
Retention enema is diagnostic and is used for finding the pathologyof lower intestines.
Drugsgiven by rectal route have 50% first pass metabolism.
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Parenteral Route:
Parenteral route includes: Injections:
Intra muscular
Intra venous
Intra-arterial Intra-cardiac
Intra-thecal
Intraosseous- into bone marrow
Intrapleural
Intraperitoneal Intra-articular
Intradermal (Intracutaneous)
Subcutaneous route (Hypodermic)
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Classification: Site of Release:
Site of release may be intradermal, intraperitoneal, intrapleural, intracardiac, intra-arterial, intrathecal (into meninges of spinal cord), intra-articular (into joint cavity).
a. Subcutaneous: Subcutaneous route might be used for the arm, forearm, thigh and subscapular space.
The volume used is 2 ml. Insoluble suspensions like insulinand solids might be applied bythis route.
Advantages: Absorptionis slow and constant
It is hygienic Disadvantages:
It might lead to abscess formation
Absorptionis limited by blood flow
Examples of drugs given by subcutaneous route include insulin, adrenaline and norplant.
b. Intramuscular route: Intramuscular route might be applied to the buttock, thigh and deltoid. The volume used is 3
ml.
Advantages: Absorptionis rapid than subcutaneous route.
Oily preparations can be used.
Irritative substances might be given
Slow releasing drugscan be given by this route.
Disadvantages Using this route might cause nerve or vein damage.
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Classification:
c. Intravenous injections: Intravenous injections might be applied to the cubital, basilic and cephalic veins.
Advantages: Immediate action takes place
This route is preferred in emergency situations
This route is preferred for unconscious patients.
Titration of dose is possible.
Large volume of fluids might be injected by this route Diluted irritant might be injected
Absorptionis not required
No first pass effect takes place.
Blood plasma or fluids might be injected.
Disadvantages: There is no retreat
This method is more risky
Sepsis-Infection might occur
Phlebitis(Inflammation of the blood vessel) might occur
Infiltration of surrounding tissues might result.
This method is not suitable for oily preparations
This method is not suitable for insoluble preparations
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Inhalation
Inhalation may be the route of choice to avoid thesystemic effects. In this way drugscan pass directly tothe lungs.Drugsused involve volatile drugs and gases.Examples include aerosols like salbutamol; steaminhalations include tincture and Benzoin
Advantages: Rapid absorptiontakes place.
Rapid onset of action takes place.
This route has minimum side effects.
No first pass effect takes place.
This method is easy.
Fewer doses is required.
Disadvantages: Special apparatus is required.
Irritation of the respiratory tract may take place.
Cooperation of the patient is required.
Airway must be patent.
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Topical route Drugsmay be applied to the external surfaces, the skin and the mucous
membranes. Topical route includes: a. Enepidermic route When the drugis applied to the outer skin, it is called enepidermic route of drug
administration. Examples include poultices, plasters, creams and ointments.
b. Epidermic route (Innunition): When the drugis rubbed into the skin, it is known as epidermic route. Examples
include different oils.
c. Insufflations: When drugin finely powdered form is blown into the body cavities or spaces with
special nebulizer, the method is known as insufflations.
d. Instillation Liquids may be poured into the body by a dropper into the conjunctival sac, ear,
nose and wounds. Solids may also be administered.
e. Irrigation or Douching
This method is used for washing a cavity e.g. urinary bladder, uterus, vagina andurethra. It is also used for application of antiseptic drugs.
f. Painting/Swabbing Drugsare simply applied in the form of lotion on cutaneous or mucosal surfaces
of buccal, nasal cavity and other internal organs.
Time of Action using Different
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Time of Action using Different
Routes of Administration
Drugstake different time durations after injectionusing different routes to perform their actions.
This time delay is important, oral route has
controlled release time, thus depot or reservoirpreparation may be made e.g. penicillin for
rheumatic fever.
Usage of drugdepends on its physical
properties, chemical properties, speed of action,need and bypass effect.
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Some of the approximate time intervals are given below:
Route of Drug Administration Delay time for Action
Intravenous route 30-60 seconds
Intraosseous route 30-60 seconds
Endotracheal inhalation 2-3 minutes
Sublingual route 3-5 minutes
Intramuscular route 10-20 minutes
Rectal route 5-30 minutes
Ingestion 30-90 minutes
System of medication
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System of medication
measurements
Metric System
Apothecary System
Household System
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Metric System
Basic unit of solid measurement is the gram,basic unit of liquid measurement is the liter, and
basic unit of length measurement is the meter.
Variations of these measurements will includethe prefixes of kilo, centi, deci, milli, micro etc.
Unit of measure follows the number
Arabic numbers are used
Fractions are expressed as decimals
Example notations: 3 g; 0.25 mg; 500 mL
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The Apothecary System
Basic unit of solid measurement is the grain and basicunits of liquid measurement include minim, dram, andfluid ounce.
Unit of measure precedes the number
Roman numerals are used for smaller numbers. Arabicnumbers are more commonly used if larger numbers.
Fractions are expressed as numerical fractions. A small"ss" may be used to represent 1/2.
Example notations: gr iiss; drams 3 (NOTE: There aresymbols to represent dram and ounce which cannot bereproduced here. Refer to page 9 in the Drug DosageLab document to see these symbols.)
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Household system
Basic units of solid measurement arepounds and ounces and units of liquidmeasurement include teaspoon,
tablespoon, cups, etc. Unit of measure follows the number
Arabic numbers are used
Fractions are expressed as numericalfractions
Example notations: 1/2 t; 125 lbs
The Nursing
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The NursingProcess
Assessment
Nursing diagnosis
Planning (with outcome criteria)
Implementation
Evaluation
The Nursing Process (cont'd)
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The Nursing Process (cont d)
Assessment
Data collection
Subjective, objective
Data collected on the patient, drug, environment
Medication history
Nursing assessment
Physical assessment Data analysis
Th S
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The Seven
Rights Right drug
Right dose Right time
Right route
Right patient Right to refuse
Right documentation
Another
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Another
Right
Constant
System
Analysis
A double-check
The entire system ofmedication administration
Ordering, dispensing,preparing, administering,documenting
Involves the physician,nurse, nursing unit,pharmacy department,and patient education
Other Rights
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Other Rights
Proper drug storage
Proper documentation
Accurate dosage calculation
Accurate dosage preparation
Careful checking of transcription of orders
Patient safety
Other Rights (cont'd)
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Other Rights (cont d)
Close consideration of special situations
Prevention and reporting of medication
errors
Patient teaching
Monitoring for therapeutic effects, side
effects, toxic effects
Refusal of medication
Evaluation
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Evaluation
Ongoing part of the nursing process
Determining the status of the goals and
outcomes of care
Monitoring the patients response to drug
therapy
Expected and unexpected responses
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The day shift charge nurse is making rounds. Apatient tells the nurse that the night shift nurse
never gave him his medication, which was due at
11 PM. What should the nurse do first to
determine whether the medication was given?
1. Call the night nurse at home.
2. Check the Medication Administration Record.
3. Call the pharmacy.
4. Review the nurses notes.
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The patients Medication Administration Recordlists two antiepileptic medications that are due at
0900, but the patient is NPO for a barium study.
The nurses coworker suggests giving the
medications via IV because the patient is NPO.What should the nurse do?
1. Give the medications PO with a small sip of water.
2. Give the medications via the IV route because the
patient is NPO.3. Hold the medications until after the test is
completed.
4. Call the physician to clarify the instructions.
Life Span Considerations
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Life Span Considerations
Pregnancy
Breast-feeding
Neonatal
Pediatric
Geriatric
Pregnancy
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Pregnancy
First trimester is the period of greatestdanger for drug-induced developmental
defects
Drugs diffuse across the placenta FDA pregnancy safety categories
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Table 3-1
Pre nanc
Breast-feeding
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Breast feeding
Breast-fed infants are at risk for exposureto drugs consumed by the mother
Consider risk-to-benefit ratio
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Pediatric Considerations:
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Pediatric Considerations:
Pharmacokinetics
Absorption
Gastric pH less acidic
Gastric emptying is slowed Topical absorption faster through the skin
Intramuscular absorption faster and irregular
Pediatric Considerations:
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Pediatric Considerations:
Pharmacokinetics (cont'd)
Distribution
TBW 70% to 80% in full-term infants, 85%in premature newborns, 64% in children
1 to 12 years of age
Greater TBW means fat content is lower Decreased level of protein binding
Immature blood-brain barrier
Pediatric Considerations:
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Pediatric Considerations:
Pharmacokinetics (cont'd)
Metabolism
Liver immature, does not produce enough
microsomal enzymes
Older children may have increased
metabolism, requiring higher doses
Other factors
Pediatric Considerations:
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Pediatric Considerations:
Pharmacokinetics (cont'd)
Excretion
Kidney immaturity affects glomerular filtrationrate and tubular secretion
Decreased perfusion rate of the kidneys
Summary of Pediatric
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y
Considerations
Skin is thin and permeable
Stomach lacks acid to kill bacteria
Lungs lack mucus barriers
Body temperatures poorlyregulated and dehydration occurseasily
Liver and kidneys are immature,impairing drug metabolism andexcretion
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Methods of Dosage Calculation for
Pediatric Patients
Body weight dosage calculations
Body surface area method
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Geriatric Considerations
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Geriatric Considerations
Geriatric: older than age 65 Healthy People 2010: older than age 55
Use of OTC medications
Polypharmacy
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Geriatric Considerations:
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Pharmacokinetics
Absorption
Gastric pH less acidic
Slowed gastric emptying
Movement through GI tractslower
Reduced blood flow to the
GI tract Reduced absorptive
surface area due to
flattened intestinal villi
Geriatric Considerations:
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Geriatric Considerations:
Pharmacokinetics (cont'd)
Distribution
TBW percentages lower
Fat content increased
Decreased production of proteins by the liver,
resulting in decreased protein binding ofdrugs
Geriatric Considerations:
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Pharmacokinetics (cont'd)
Metabolism
Aging liver produces less microsomal
enzymes, affecting drug metabolism
Reduced blood flow to the liver
Geriatric Considerations:
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Geriatric Considerations:
Pharmacokinetics (cont'd)
Excretion
Decreased glomerular filtration rate
Decreased number of intact nephrons
Geriatric Considerations: Problematic
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Medications
Analgesics
Anticoagulants
Anticholinergics
Antihypertensives
Digoxin
Sedatives and hypnotics
Thiazide diuretics
Ethical Nursing Practice
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g
American Nurses Association (ANA) Codeof Ethics for Nurses
Cultural Considerations
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Assess the influence of a
patients cultural beliefs,values, and customs
Drug polymorphism
Compliance level with
therapy Environmental
considerations
Genetic factors
Varying responses tospecific agents
Cultural Assessment
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Health beliefs and practices
Past uses of medicine
Folk remedies
Home remedies
Use of nonprescription drugs and herbal
remedies
OTC treatments
Cultural Assessment
( t'd)
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(cont'd)
Usual response to treatment
Responsiveness to medical treatment
Religious practices and beliefs
Dietary habits
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Preparing for Drug
Ad i i t ti
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Administration
Check the 7 rights
Standard Precautions: Wash your hands!
Double-check if unsure about anything
Check for drug allergies
Prepare drugs for one patient at a time
Check three times Check expiration dates
Check the patients identification (2 identifiers)
Give medications on time
Explain medications to the patient Open the medications at the bedside
Document the medications given before going to thenext patient
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Enteral Drugs
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Enteral Drugs
Giving oral medications
Giving sublingual or buccal medications
Liquid medications
Giving oral medications to infants
Administering drugs through a
nasogastric or gastrostomy tube
Rectal administration
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Parenteral Drugs
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g
Never recap a used needle! May recap an unused needle with the scoop
method
Prevention of needlesticks
Filter needles
Removing medications from ampules
Removing medications from vials
Disposal of used needles and syringes Needle Selection
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Injections
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Injections
Needle angles for various injections Intramuscular (IM)
Subcutaneous (SC or SQ)
Intradermal (ID)
Z-track method for IM injections
Air-lock technique
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Injection Techniques
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Injection Techniques
Intradermal injections
Subcutaneous injections Insulin administrationAnticoagulant administration (Heparin/Lovenox)
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Injection Techniques
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j q
(cont'd) Intramuscular injections Ventrogluteal site (preferred)
Vastus lateralis site
Dorsogluteal site Deltoid site
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Preparing
Intra eno s
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Intravenous
Medications Needleless systems
Compatibility issues
Expiration dates
Mixing intravenouspiggyback (IVPB)medications
Labeling intravenous(IV) infusion bags whenadding medications
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Intravenous
M di i
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Medications
(cont'd) Volume-controlled administration set
Using electronic infusion pumps
Patient-controlled analgesia (PCA) pumps
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Topical Drugs
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p g
Eye medications Drops
Ointments
Ear drops
Adults
Infant or child younger than3 years of age
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Topical Drugs (cont'd)
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p g ( )
Nasal drugs Drops
Spray
Inhaled drugs
Metered-dose inhalers
Small-volume nebulizers
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