A representative set of clinical drug-drug interactions due to P450 induction


Inducer (Substrate)

Clinical Effect

CYP1A2 Omeprazole (caffeine) 39% Increase in exhalation of [14C]CO2 in CYP2C19 poor and intermediate metabolizers compared with 12% increase in extensive metabolizers Rost et al., 1992
CYP2B6 Rifampicin (bupropion) Apparent clearance increased from 2.6 l/h/kg to 7.9 l/h/kg Loboz et al., 2006
CYP2C9 Rifampicin (celecoxib) AUC decreased by 64% Jayasagar et al., 2003
CYP2E1 Alcohol (chlorzoxazone) Total plasma clearance 73% higher in alcoholics Girre et al., 1994
CYP3A4 Efavirenz (simvastatin) Simvastatin-acid AUC decreased 58%, and HMG-CoA activity decreased 60% Gerber et al., 2005
CYP3A4 and -2C8 Rifampicin (repaglinide) AUC decreased by 57%; blood glucose decremental AUC (0-3 h) reduced from 0.94 to -0.23 mmol/l Niemi et al., 2000
Multiple Lopinavir/ritonavir
    CYP1A2 (caffeine) Urinary metabolite ratios increased by 43% Yeh et al., 2006
    CYP2C9 (warfarin) AUC decreased by 1.4-fold
    CYP2C19 (omeprazole) Omeprazole/5-hydroxyomeprazole ratio decreased 2.7-fold
Apparent clearance decreased by 12-fold