PK Paed

Question 1

Gastric pH

Answer 1

Birth = 6-8 (neutral)

Adult values = 20-30 months of age

Relatively increased

Question 2

Gastric emptying

Answer 2

At 6-8 hr = irregular

After 6 months = adult values

Question 3

Total body water

Answer 3

Increases

Decrease concentration of hydrophilic drug

Question 4

A1 glycoprotein

Answer 4

Decreases

Increase free fraction of basic drug

Question 5

Hepatic mass

Answer 5

Full function at 6 months

Question 6

Enzyme activity!!

Answer 6

Cyp3A4 INCR. with age
Cyp3A7 INCR. then decline—
Cyp1A4 INCR. slowly, reach adult by 1 year

Question 7

Renal function

Answer 7

Diminished at birth,

Adult values by 1-3 years

Question 8

Percutaneous absorption

Answer 8

Increases

Increase absorption of topical agents
Increase toxicity

Question 9

What does an increased gut pH do to acidic drugs (phenytoinl

Answer 9

Reduced absorption of weak acids (phenytoin) therefore INCREASE the dose

Question 10

Bile secretion in the first 2-3 weeks is…

Answer 10

POOR

REDUCED ABSORPTION of poorly soluble drugs and fat soluble vitamins