Imatinib Rifampicin

ST JOHN S WORT IMATINIB 1 imatinib levels Due to induction of CYP3A4-mediated metabolism of imatinib Monitor for clinical efficacy and adjust dose as required. Avoid co-administration of imatinib and rifampicin... 

Clinically important, potentially hazardous interactions with albendazole, aminoglutethimide, aspirin, bexarotene, carbamazepine, cyclophosphamide, dasatinib, diuretics, ephedrine, imatinib, itraconazole, lapatinib, live vaccines, lopinavir, methotrexate, phenobarbital, phenytoin, praziquantel, primidone, rifampicin, rifampin, temsirolimus, warfarin... 

Rifampicin (rifampin) and St John s wort Hypericum perforatum) lower serum imatinib levels other CYP3A4 inducers (such as carbamazepine, phenobarbital and phenytoin) are predicted to... 

A study reported that pretreatment with rifampicin 600 mg daily for 11 days decreased the maximum serum levels and AUC of a 400 mg dose of imatinib by 54% and 74%, respectively. ... 

Rifampicin is a known potent inducer of many cytochrome P450 isoenzymes, including CYP3A4, by which imatinib is metabolised. Therefore rifampicin increases imatinib metabolism and decreases its levels. St John s wort induces intestinal CYP3A4 and it therefore also reduces imatinib levels. 

Subtherapeutic levels of imatinib may occur if rifampicin is given. The manufacturers therefore reasonably reeommend caution, and suggest that concurrent use with potent enzyme-inducing drugs should be avoided. St John s wort has smaller effects, but they may be sufficient to impair the effects of imatinib, and it has therefore been suggested that concurrent use should also be avoided. ... 

Bolton AE, Peng B, Hubert M, Krebs-Brown A, Capdeville R, Keller U, Seiberling M. Effect of rifampicin on the pharmacokinetics of imatinib mesylate (Gleevec, STI571) in healthy subjects, Cancer ChemotherPharmacol 2004) 53,102-6. 

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