Nimodipine Cimetidine

Muck W, Wingender W, Seiberling M, Woelke E, Ramsch KD, Kuhlmann J. Influence of the H2-receptor antagonists cimetidine and ranitidine on the pharmacokinetics of nimodipine in healthy volunteers. Eur J Chn Pharmacol 1992 42(3) 325-8. 

Clinically important, potentially hazardous interactions with amlodipine, bepridil, cimetidine, diltiazem, felodipine, isradipine, nicardipine, nifedipine, nimodipine, nisoldipine, verapamil... 

The plasma levels of diltiazem, isradipine and nifedipine are increased by cimetidine and it may possibly be necessary to reduce the dosages of these calcium-channel blockers. High doses of cimetidine may increase the bioavailability of lercanidipine. Although studies surest no important interactions occur between nicardipine or nisoldipine and cimetidine, the manufacturers advise caution. Plasma felodipine, lacidipine, nimodipine, and... 

Cimetidine 1 g daily for 7 days ineieased the bioavailability of nimodipine 30 mg three times daily in 8 healthy subjects by 75%, but the haemodynamic effects were unchanged. Ranitidine did not interact. ... 

Ranitidine does not interact significantly with diltiazem, nimodipine, nisoldipine or nifedipine, and is possibly a non-interacting alternative for cimetidine with other calcium-channel blockers. Note that the nitrendipine AUC was increased by 50% and 89% by ranitidine, although this was not considered clinically relevant. 

Phenobarbital and phenytoin reduce the serum levels of tirilazad mesilate whereas ketoconazole increases them. Finasteride inhibits the metabolism of tirilazad to its active metabolite. No pharmacokinetic interaction appears to occur between cimetidine or nimodipine and tirilazad. 

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