Pediatric, Geriatric, Pregnancy, Lactation

1. Drug use in special situations
• Geriatric drug therapy
• Pediatric drug therapy
• Drugs in Pregnancy &Lactation

2. GERIATRIC DRUG THERAPY
Geriatric (elderly) patients use more medications compared
to younger patients because they have more symptoms of
disease.
Clinical changes in elderly:
• Lean body mass diminishes by 20-30%.
• Fat free mass diminishes.
• Total albumin is reduced in elderly by 20%.
• There is 12% loss of tissue bone in male & 25% in female.
• The brain achieves its optimal potential at 16-20 years after
which there is slow decline in capabilities.
• Insulin clearance reduces.
• Blood concentrations, basal output & metabolic turnover of
major harmones like estrogen, testosterone, thyroxine,
androgen, angiotensin & aldosterone have reported to
decline with age.

3. Effect of aging on drugs
• Many of the Adverse Drug Reactions
encountered in elderly are the result of the
dose related pharmacokinetic changes.
• The aging process influences drug response by
interfering with fraction of drug absorbed (f),
plasma drug half life (t1/2), volume of
distribution (Vd) and drug clearance (CL) from
the body.

4. Factors governing drug use in special situations:
PHARMACOKINETICS
Age related changes influencing Absorption
• Reduced gastric acid secretion
• Impaired drug absorption
• GI motility & intestinal blood flow is reduced
• Collateral circulation bypassing liver
• Reduced active transport mechanism
Age related changes influencing Distribution
• Reduction in serum albumin concentration
• Reduction in erythrocyte binding
• Smaller volume of distribution due to reduced body water
• Increased volume of distribution for lipophilic drug due to
more fat

5. Age related changes influencing Metabolism
• Reduction in liver mass
• Reduced hepatic metabolizing enzymes
• Reduced liver blood flow
• Decrease in cytochrome P450
Age related changes influencing Elimination
• Reduction in total number of functioning nephrons
• Reduced renal plasma flow
• Reduced glomerular filtration rate
• Impaired renal tubular secretion

6. Age related PHARMACODYNAMIC changes in
elderly
• Depletion of neurotransmitters
• Decrease in baroreceptor activity
• Reduced responsiveness to beta adrenergic
receptors
• Increased pain tolerance
• Changes in laboratory values

7. PEDIATRIC DRUG THERAPY
• Drug treatment for infants & children requires
knowledge of drug response in early years of life.
Pharmacokinetic Factors:
• Pharmacokinetic changes occurs from few
months to 3 or 4 years of life.
Absorption
• Rate of absorption may be increased by the use
of liquid preparations.

8. Distribution
• Total volume of body water & extracellular fluid
related to body weight are greatest during
neonatal period & infancy.
• Blood brain barrier may be functionally
incomplete in neonates, which permits increased
penetration by some drugs
Metabolism
• Metabolism of most drugs proceeds comparatively
slowly in first few weeks of life & later increases up
to 2-3 years of life.
• After they reduce gradually until adolescence.

9. Elimination
• Drug metabolites are eliminated primarily through
bile or the kidneys. Renal elimination depends on:
A. Plasma protein binding
B. Renal blood flow
C. GFR
D. Tubular secretion
• All of these factors are altered in the first 2 yr of life.
Renal plasma flow is low at birth (12 mL/min) and
reaches adult levels of 140 mL/min by age 1 yr.
Similarly, GFR is 2 to 4 mL/min at birth, increases to
8 to 20 mL/min by 2 to 3 days, and reaches adult
levels of 120 mL/min.

10. Calculation of doses
• Individual dose = body weight(kg) × average adult dose
70
• Young’s Formula
• Child dose = age × adult dose
age + 12
• Diling’s Formula
• Child Dose = age × adult dose
20

11. DRUGS IN PREGNANCY & LACTATION
• The use of drugs during pregnancy must be
avoided unless absolutely necessary.
• The foetus or neonate must always be kept in
mind as a potential recipient of the drug.
• Placental barrier is selective membrane but
cannot block all the drugs from passing to
foetus.

12. FDA pregnancy category list

13. Teratogens
• A teratogen is an agent, which can cause a
birth defect.
• Teratogens are agents including viruses, drugs,
chemicals, stressors, and malnutrition, which
can impair prenatal development and lead to
birth defects or even death.
• Examples: Thalidomide, Phenytoin, Alchohol,
Viruses like Varicella, etc

15. THANK YOU FOR YOUR ATTENTION!