Pediatrics 5

Question 1

what can chloramphenicol cause

Answer 1

gray baby syndrome

Question 2

what can cause kernicterus? why?

Answer 2

sulfisoxazole; unable to metabolize bilirubin

common in jaundice babies receiving sulfa drugs

Question 3

what drug causes “seal babies”

Answer 3

thalidomide

Question 4

what is a general rule in dose standardization?

Answer 4

standardize doses either as amount per kg or amound per BSA

Question 5

If dosing of acyclovir for HSV is 60 mg/kg/day; is a 4 kg 5 day old started on 80 mg q8h appropriate?

Answer 5

(step 1 calculate total dose per day = 80 x 3 240 mg/ day)

step 2 total mg/kg/day = 240 mg/day divided by 4 kg = 60 mg/kg/day

Question 6

id zidovudine is dosed at 180 mg/m2 every 12 hours; what dose would you recommend for a 3 month old who weighs 6 kg and is 55 cm long

Answer 6

1. BSA = sqrt (6 kg x 55 cm)/3600 = 0.3 m2
2. 0.3 m2 x180 mg/m2 = 54 mg
3. formulation of this is 50 mg/ 5ml so 50 mg (1 tsp) every 12 hours in an oral syringe

Question 7

what should be used for dosing references

Answer 7

pediatric dosage handbook or pediatric lexicomp (not just regular lexicomp)

Question 8

why are there age specific dosing regimens

Answer 8

“children are not miniature adults” and human growth is not a linear process

Question 9

how much weight do new borns typically gain per day in the first few months of life

Answer 9

30-40g per day

Question 10

when should a baby return to there orginal birthweight after they lose some weight initially

Answer 10

7-10 days (about a week)

Question 11

what are the 4 big pharmacokinetic variables

Answer 11

1. Ke
2. half life
3. volume of distribution
4. clearance

Question 12

what are the 2 independent pharmacokinetic variables

Answer 12

clearance and volume of distribution

Question 13

what pharmacokinetic variable has to do with dosing interval

Answer 13

clearance

Question 14

what pharmacokinetic variable has to do with amount per dose

Answer 14

volume of distribution

Question 15

how is a neonates GI tract different than a normal person

Answer 15

high pH (effecting drugs absorption)

Question 16

gastric emptying and intestinal motility matures by what age

Answer 16

4 months

Question 17

how does the ratio of total body weight: BSA compare from a baby to an adult

Answer 17

total body weight: BSA is greater in infants than adults

Question 18

What lab value is difficult to measure in patients without a large muscle mass (ie babies)

Answer 18

serum creatinine

Question 19

what pharmacokinetic distribution factors are directly related to gestational age

Answer 19

1. bilirubin
2. fetal albumin
3. acid/base
4. glycoproteins

Question 20

why are aminoglycoside doses so different in babies verse adults

Answer 20

aminoglycosides distribute to ECF and babies have a larger volume of distribution so need a larger dose

Question 21

why are phenytoin doses so different in babies verse adults

Answer 21

phenytoin is highly protein bound; free concentration is active, so smaller doses in babies do to lower levels of albumin

Question 22

metabolism can occur where is other than the liver

Answer 22

1. blood
2. lung
3. GI tract
4. kidney

Question 23

at what age is the highest dose of phenobarbital the needed

Answer 23

ages 1-5

Question 24

why does theophylline work so well in neonates

Answer 24

goes through N-methylation and is broke down into caffeine

instead of N-demethylation that occurs in adults

Question 25

what are the 3 different types of elimination in the kidneys.

Answer 25

1. filtration
2. reabsorption
3. secretion

Question 26

how much cardiac output do kidneys ceceive at birth

Answer 26

5-6% (compared to 15-25% in adults)

Question 27

what is the major way penicillin is eliminated in neonates? why?

Answer 27

eliminated in GFR; tubular secretion does not work well (how it is eliminated in adults)