[Pharmacokinetics of prednisone after oral administration in children with renal grafts. Changes induced by phenobarbital and renal insufficiency].
A study of blood and urinary clearance of prednisone after ingestion of a 25 mg/m2 body surface test-dose, at 8 AM, was undertaken in 20 children treated for 18 months with prednisone after renal transplant. Results show important variability between patients: the elimination half life was 2.70 +/- 0.78 hr.; Tmax time to reach Cmax was 2.10 +/- 1.08 hr.; Maximal concentration (Cmax) was 474 +/- 153 ng/ml. With respect to the dose of steroid administered, the urinary excretion of corticosteroids: 17-hydroxycorticosteroids was 12.9 +/- 7.4% and that of unchanged prednisolone 2.8 +/- 3.1%. This level was essentially achieved in the 6 first hours: 55.4 +/- 16.2% for 17-OH steroids and 87.2 +/- 14.3% for prednisolone. Two points emerge from this study: (a) Renal failure slows urinary excretion of prednisone and its metabolites, making a reduction in the doses of corticosteroids necessary at certain doses. (b) The association prednisone-phenobarbital changes the blood kinetics (excretion is faster) without a clear change in 17-OH steroid and prednisolone urinary excretion. It is associated with a decrease in graft tolerance. The kinetic changes do not seem to be the only factors implicated in the decreased therapeutic response.
D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D002648:Child; D003404:Creatinine / Q000652:urine; D004347:Drug Interactions; D005260:Female; D006084:Graft Rejection / Q000187:drug effects; D006801:Humans; D007676:Kidney Failure, Chronic / Q000378:metabolism*; D016030:Kidney Transplantation; D007700:Kinetics; D008297:Male; D010634:Phenobarbital / Q000494:pharmacology*; D011184:Postoperative Period; D011241:Prednisone / Q000008:administration & dosage / Q000378:metabolism*
D003404:Creatinine; D011241:Prednisone; D010634:Phenobarbital
Pharmacocinétique de la prednisone après dose orale chez l'enfant greffé rénal. Modifications induites par le phénobarbital et l'insuffisance rénale.