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Dear all,
Current pediatric FDA guidance (2014) states that for estimating GFR in children age <12 years
modified Schwartz equation is recommended. For children >= 12 years if age Cockcroft-Gault equation
is recommended.
But a paper published in clinical nephrology 2005 states that Cockcroft-Gault formula should not be
used in children (title of the article is same) and Schwartz formula or cystatin C–based approach
is preferred.
Please provide your inputs on this.
Thanks,
Soujanya
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Dear Soujanya,
This FDA guidance is indeed nonsense. In addition to you pointing out
C-G maybe inappropriate in adolescents, Schwartz and C-G have different
units (Schwartz scaled to BSA whereas C-G is in mL/min), and Schwartz
and C-G will have already used height, age, weight, sex to estimate
GFR. If modelling adults and children together one sensible approach is
put allometric weight scaling (and age effects if you have under 2 year
olds and/or or over ~50 year olds), and then add age-scaled serum
creatinine as a covariate. See for example:
Johansson et al Ther Drug Monit. 2011 Dec;33(6):711-8. doi:
10.1097/FTD.0b013e31823615e1.
Hennig et al Clin Pharmacokinet. 2013 Apr;52(4):289-301. doi:
10.1007/s40262-013-0036-y.
Another one I suppose would be to scale C-G by BSA and then you are
looking at deviation from an expected normal renal function, so could be
included on top of other otherwise correlated covariates.
BW,
Joe
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First some definitions:
Premature: ≤37 gestational weeks
* Premature neonate = premature
* Neonate: birth to 1 month
* Infant: 1 month to 1 year
* Children: 1 year to 12 years
* Adolescent: 12 years to 18 years
Age CrCl ml/min/1.73m2
Neonates <34 wk: 2-8 days 11-15
9-28 days 15-28
30-90 days 40-65
Neonates > 34 wk: 2-8 days 17-60
9-28 days 26-68
30-90 days 30-86
1-6 months 39-114
6-12 months 49-157
12-19 months 62-191
2 years-adult 89-165
Schwartz formula:
CrCl = K X L/Scr (ml/min/1.73m2)
Age K
< 1 year, LBW 0.33
<1 year, term 0.45
2-12 years 0.55
13-21 years, female 0.55
13-21 years, male 0.70
L= length in cm; Scr=serum creatinine in mg/dL
Traub and Johnson
n "Children" 1-18 years of age
n CrCl=(0.48 x height)/Scr (ml/min/1.73m2)
Nahata MC,etal.Pediatrics(Chapter10). In: DiPiro JT, et al, eds. Pharmacotherapy: A Pathophysiologic
Approach, 8th ed. New York, NY: McGraw-Hill, 2010.
William R. Wolowich, Pharm.D., R.Ph.
Assistant Professor
Department of Pharmacy Practice
College of Pharmacy
Nova Southeastern University
Ft. Lauderdale, Florida, USA
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