Pediatric - Geriatric Pharmacology

Question 1

By __ year of age adult-child differences are ___ substantial

Answer 1

1 yr of age, differences are NOT substantial

Question 2

Do loading doses of drugs change for children?

Answer 2

No, change very little

Question 3

How is hepatic metabolism different in neonates?

Answer 3

Highly variable

Question 4

Significance of cytochrome 2E1

Answer 4

Enzyme that metabolizes ethanol; takes acetominophen and makes it toxic. Ethanol induces this.

Question 5

Differences in dev of Phase 1 pathways of drugs

Answer 5

CYP1A2 reach adult levels by 4-5 months
CYP2C9 > adult levels at teens
CYP2D6 adult levels by 10 yrs (no activity at birth)
CYP3A4 > adult levels by 1 yr

Question 6

Grey baby syndrome can be found with which drug?

Answer 6

Chloramphenicol

Question 7

When is renal clearance more predictable?

Answer 7

Outside of the neonatal period

Question 8

Which is more predictable in kids - renal or hepatic elimination?

Answer 8

Renal

Question 9

In general, drugs are cleared ___ in children and so maintenance doses are ___ than in adults

Answer 9

Cleared more rapidly so maintenance dose is higher than encountered in adults

Question 10

Do the therapeutic levels of drugs (Cp) change between children and adults?

Answer 10

No, they are the same. But do make sure to calculate with appropriate surface area

Question 11

Which drug classes do you worry about GH for kids?

Answer 11

CNS stimulants, Anti-inflammatory corticosteroids, psychoactive agents

Question 12

Which drugs do you worry about intellectual development in kids?

Answer 12

Barbiturates

Question 13

Which drugs do you worry about bone and teeth in kids?

Answer 13

Tetracyclines

Question 14

Which drugs do you worry about hepatic dysfunction in kids?

Answer 14

Aspirin (salicylates)

Increased risk of Reyes Syndrome

Question 15

Summary of geriatric absorption pharmacokinetics

Answer 15

Rate of absorption may change slightly

Extent of absorption will be unchanged for most medications with aging

Question 16

What do digoxin, aminoglycosides, and lithium have in common with geriatrics?

Answer 16

May require a lower loading dose because a decrease in Vd for water soluble drugs will result in higher plasma concentrations

Question 17

What do chlordiazepoxide and diazepam have in common?

Answer 17

Increase in Vd for relatively lipid soluble drugs = slower elimination which allows for drug accumulation

• May require higher loading dose but lower maintenance dose
• Changes in clearance are more likely to affect half life and MD.

Question 18

The Old Liver

Answer 18

Temazepam, Oxazepam, Lorazepam - Phase II reactions are minimally affected by aging (conjugation, glucuronidation)

Question 19

If you have a choice amongst agents in a therapeutic class, which ones should you pick?

Answer 19

Those undergoing phase II metabolism because they are more reliably eliminated