Pediatric and Geriatric Pharmacology

Pediatric and Geriatric Nursing Pharmacology lecture notes


Pediatric Pharmacology
Pharmacokinetics
Absorption
Gastric pH alkaline at birth and does not reach adult acidity until age 1-3y
Gastric emptying prolonged in neonates
Greater GI surface area can increase absorption in infants and young children
Topicals more readily absorbed due to thinner, more porous skin in infants and young children


Pediatric Pharmacology
Pharmacokinetics
Distribution
Children under 2y require higher doses of water soluble medications and lower doses of lipid soluble medications
Infants have less albumin and need less of highly protein bound drugs

Pediatric Pharmacology
Pharmacokinetics
Metabolism
Infants have slower metabolic rate but then this speeds up in children
First pass effect can be problematic – sometimes resulting in oral route being bypassed in favor of another route (ex. Rectal)
Excretion
Reduced function until about 9m of age
Can be reduced again in adolescence


Pediatric Pharmacology
Pediatric Medication Administration
Dosing based on:
Weight (kg)
Body surface area (BSA)
Consider developmental age when administering medications
Use topical analgesics prior to painful injections

Drug Therapy in Geriatric Patients
Elderly patients constitute 12% of the population but use 31% of the nation’s prescribed drugs


Drug Complications in the Elderly
Contributing factors to drug complications are
Altered pharmacokinetics
Multiple illnesses
Multiple drug therapy/polypharmacy
Poor compliance


Altered Pharmacokinetics

Distribution
Geriatric Pharmacology
Pharmacokinetics
Absorption is slowed
Distribution changes due to loss of water and increase in adipose tissue
Metabolism is slowed due to diminished liver function
Excretion is slowed due to diminished kidney function and decreased cardiac output
Metabolism
Decreased hepatic metabolism
Renal Excretion
In the elderly, the proper index of renal function is creatinine clearance, not serum creatinine
Excretion
Reduced renal excretion

Adverse Drug Reactions
Seven times more likely in elderly
16% of hospital admissions
50% of all medication-related deaths

Polypharmacy – the use of multiple drugs together
Contributes to:
Falls
Incontinence
Confusion
Malnutrition
Renal dysfunction
Liver dysfunction
Nonadherence

Monitoring for Adverse Drug Reactions
Take thorough drug history
Low dosing
Plasma level monitoring
Simplest regimen
Review drug treatment schedule


Promoting Compliance
Simple drug regimen
Verbal and written instructions
Appropriate dosage form
Clear labeling
Daily reminders
Support system
Frequent monitoring


Geriatric Pharmacology
Effects of Selected Drugs in Older Adults
Hypnotics / Sedatives
More sensitive to medication – need lower doses
Diuretics and Anti-hypertensives
More prone to electrolyte disturbances, orthostatic hypotension
Cardiac Glycosides
Lower dose needed due to reduced renal function
Anti-coagulants
Highly-protein bound – bleeding problems can occur as elderly often have less protein reserves


Geriatric Pharmacology
Effects of Selected Drugs in Older Adults
Anti-bacterials
Dose may need to be reduced due to decreased renal function
Gastrointestinal drugs
Laxative use can cause electrolyte disturbances
Cimetidine (Tagamet) – many drug interactions
Anti-depressants
TCAs less useful – strong anticholinergic properties


Patient Education
Medication generic and trade names
Dose
Use
Self-administration
Diet changes
Side Effects
Cultural / Home / Work Considerations