Epirubicin Cimetidine

CIMETIDINE EPIRUBICIN t epirubicin levels, with risk of toxicity Attributed to inhibition of hepatic metabolism of epirubicin by cimetidine Avoid concurrent treatment and consider using an alternative H2 receptor blocker, e.g. ranitidine, famotidine... 

In a study in 8 patients, cimetidine 400 mg twice daily increased the AUC of epirubicin by 50%. At the same time the AUCs of two metabolites of epirubicin, epirubicinol and 7-deoxydoxorubicinol aglycone, increased by 41% and 357%, respectively. Liver blood flow also increased by 17%. The mechanism is unknown. More study of this interaction is needed but be aware of the possibility of cimetidine inereasing the exposure to epirubicin monitor the patient closely and adjust epirubicin dosage if needed. Cimetidine is available without a preseription in some countries so that patients may unwittingly increase the toxicity of epirubicin. Cimetidine has also increased the levels or toxicity of some other antineoplastics, see Nitrosoureas + Cimetidine , p.655, Cyclophosphamide + H2-receptor antagonists , p.626 and Fluorouracil + H2-reeeptor antagonists , p.633. 

Murray LS, Jodrell DI, Morrison JG, Cook A, Kerr DJ, Whiting B, Kaye SB, Cassidy J. The effect of cimetidine on die pharmacokinetics of epirubicin in patients widi advanced breast cancer preliminary evidence of a potentially common drug interaction. Clin Oncol( 99Z) 10,... 

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