1. Pharmacogenomics
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2. Factors that influence medication actions
3. Drug levels
Time course of drug response
Plasma drug levels
Half life
Plateau
Reducing fluctuations
4. Pharmacology
Drug tolerance
Unusually low physiologic activity in response to a drug
Person requires increased doses to get therapeutic effect
5. Pharmacology
Cumulative effect
Increasing response to repeated doses
Occurs when rate of administration exceeds rate of metabolism
Drug builds up; toxicity occurs
6. Pharmacology
Idiosyncratic effect
Under or over response
Unexpected, unpredictable, unexplainable
Drug interaction
Occurs before, during, after administration of another drug
Can be synergistic or potentiating or can be inhibiting
7. Side effect unintended effect
Adverse effect- unexpected and can be severe
Drug toxicity- buildup of drug in blood
Drug allergy- occurs after administration and can be anaphylactic
SOB, tachy, hypotension, stridor
Emergency
8. Neonatal and Pediatric Considerations: Pharmacokinetics
Absorption
Gastric pH less acidic
Gastric emptying is slowed
Intramuscular absorption faster and irregular
9. Neonatal and Pediatric Considerations: Pharmacokinetics (contd)
Distribution
The younger the person, the greater the % of total body water
Greater TBW means fat content is lower
Decreased level of protein binding
Immature blood-brain barriermore drugs enter the brain
10. Neonatal and Pediatric Considerations: Pharmacokinetics (contd)
Metabolism
Liver immature, does not produce enough microsomal enzymes
Older children may have increased metabolism, requiring higher doses than infants
Other factors
11. Neonatal and Pediatric Considerations: Pharmacokinetics (contd)
Excretion
Kidney immaturity affects glomerular filtration rate and tubular secretion
Decreased perfusion rate of the kidneys may reduce excretion of drugs
12. Factors Affecting Pediatric Drug Dosages
Skin is thin and permeable
Stomach lacks acid to kill bacteria
Lungs have weaker mucus barriers
Body temperatures less well regulated and dehydration occurs easily
Liver and kidneys are immature, impairing drug metabolism and excretion
13. Methods of Dosage Calculation for Pediatric Patients
Body surface area method
Using the West nomogram
Body weight dosage calculations
Using mg/kg
14. The Elderly
Elderly: older than age 65
Healthy People 2010: older than age 55
Use of OTC medications
Increased incidence of chronic illnesses
Polypharmacy
15. Physiologic Changes in the Elderly Patient
Cardiovascular
Gastrointestinal
Hepatic
Renal
16.The Elderly: Pharmacokinetics
Absorption
Gastric pH less acidic
Slowed gastric emptying
Movement through GI tract slower
Reduced blood flow to the GI tract
Reduced absorptive surface area due to flattened intestinal villi
17. The Elderly: Pharmacokinetics (contd)
Distribution
TBW percentages lower
Fat content increased
Decreased production of proteins by the liver, resulting in decreased protein binding of drugs (and increased circulation of free drugs)
18. The Elderly: Pharmacokinetics (contd)
Metabolism
Aging liver produces fewer microsomal enzymes, affecting drug metabolism
Reduced blood flow to the liver
19. The Elderly: Pharmacokinetics (contd)
Excretion
Decreased glomerular filtration rate
Decreased number of intact nephrons
20. The Elderly:Problematic Medications
Analgesics, including NSAIDs
Anticoagulants
Anticholinergics
Antidepressants
Antihypertensives
Cardiac glycosides (digoxin)
Sedatives and hypnotics
Thiazide diuretics
21. Factors effecting medication action
Developmental factors
Gender
Cultural, ethnic, genetic
Diet
Environment
22. Developmental considerations:
Children
Dont say candy
Use liquid
Dont lie about injections
Older adults
Altered memory
Renal function, liver function
Decreased absorption in GI tract
Altered quality of organ response to drug
23. The end