TY - JOUR
T1 - Theophylline‐rifampicin interaction
T2 - non‐selective induction of theophylline metabolic pathways.
AU - Robson, RA
AU - Miners, JO
AU - Wing, LMH
AU - Birkett, DJ
PY - 1984/9
Y1 - 1984/9
N2 - The effect of rifampicin pre‐treatment (600 mg daily for 6 days) on theophylline disposition at steady state was investigated in six healthy males. Following rifampicin treatment total plasma clearance of theophylline increased by 82%. Theophylline clearance through each metabolic pathway was increased, 1‐demethylation by (116 +/‐ 34%) (mean +/‐ s.e. mean), 3‐demethylation by (91 +/‐ 16%) and 8‐oxidation by (81 +/‐ 17%). Renal clearance of unchanged drug was not altered. Previous studies have suggested that two forms of cytochrome P‐450 are involved in theophylline metabolism, one mediating the N‐demethylations and the other 8‐oxidation. Thus, unlike the selective inductive effect of rifampicin on antipyrine metabolic pathways, rifampicin does not differentially affect those forms of cytochrome P‐450 involved in theophylline metabolism. The extent to which theophylline metabolism is induced by rifampicin is likely to have important clinical consequences. 1984 The British Pharmacological Society
AB - The effect of rifampicin pre‐treatment (600 mg daily for 6 days) on theophylline disposition at steady state was investigated in six healthy males. Following rifampicin treatment total plasma clearance of theophylline increased by 82%. Theophylline clearance through each metabolic pathway was increased, 1‐demethylation by (116 +/‐ 34%) (mean +/‐ s.e. mean), 3‐demethylation by (91 +/‐ 16%) and 8‐oxidation by (81 +/‐ 17%). Renal clearance of unchanged drug was not altered. Previous studies have suggested that two forms of cytochrome P‐450 are involved in theophylline metabolism, one mediating the N‐demethylations and the other 8‐oxidation. Thus, unlike the selective inductive effect of rifampicin on antipyrine metabolic pathways, rifampicin does not differentially affect those forms of cytochrome P‐450 involved in theophylline metabolism. The extent to which theophylline metabolism is induced by rifampicin is likely to have important clinical consequences. 1984 The British Pharmacological Society
UR - http://www.scopus.com/inward/record.url?scp=0021149092&partnerID=8YFLogxK
U2 - 10.1111/j.1365-2125.1984.tb02487.x
DO - 10.1111/j.1365-2125.1984.tb02487.x
M3 - Article
C2 - 6487483
AN - SCOPUS:0021149092
SN - 0306-5251
VL - 18
SP - 445
EP - 448
JO - British Journal of Clinical Pharmacology
JF - British Journal of Clinical Pharmacology
IS - 3
ER -