Pediatric Pharmacology. Zager. Katelyn Rogers. 03.24.10.
Disclaimer:
-Pediatric Pharmacology is a diverse and involved subspecialty
-This presenter is not a pharmacist
Pediatric Rx Principles
-Children are not merely “small” adults
-Weight-based dosage calculations are commonly used
-Developmental physiology may affect dosages for various drugs
-Breast fed infants indirectly receive their mother’s medications
-Most meds were tested in adult studies
-There’s a lot we don’t know!
The Neonate Example
Renal blood flow increases 10-fold in the first year of life (impt for
renal clearance)
GFR also changes:
Premie GFR= 0.8 ml/min
Term infant GFR= 6-20 ml/min
“Adult” GFR is achieved around 6 mos
(“Adult” GFR is > 100 ml/min)
Drug dosing variables
Other drug competing for enzymes? For ex. Prevaced & Coumadin
Other drug displacing from protein binding (i.e., albumin)bioavailability
Renal clearance varies by hydration and maturation For ex.
Acetominophen
And on… and on… and on….
Example, Part 2
Always looking this stuff up. Often get drug levels & pharm help
decide adjustments.
Summary:
Dosage by weight is commonly employed
Developmental physiology counts
Pregnancy, lactation meds affect infants
Databases should be consulted routinely
Questions:
1. T/F. Age-based dosage calculations are commonly used
for pediatric Rx.
2. RBF inceases ______ fold in ______ year(s).
3. What is a breast feeding “2” indicative of?
4. What is a pregnancy “B” indicative of?
Breast feeding Categories
Compatible
Use with caution
Unknown with concern
Contraindicated
Safety not established
Pregnancy Categories
A. Adequate studies have not shown risk
B. Animal studies have not shown risk
C. Animal studies have shown risk but human studies do not
D. Animal studies show risk- no human studies available
X. Human risk has been shown but potential benefits may warrant
use
Risk is shown and outweighs any benefit
Example dosage guide:
You can see how quickly GFR chaings. Look at icons: little kidney
 excreted by kidney, breast means mostly safe, and category B.
Category icons:
Kidney “yes”: need for caution in the face of renal failure
Breast feeding “2”: use with caution
Pregnancy “B”: some evidence for safety
Answers:
1. F. Rather weight-based.
2. 10, the first year.
3. Use with caution
4. Some evidence of safety.