Nifedipine Dalfopristin

CALCIUM CHANNEL BLOCKERS QUINUPRISTIN/ DALFOPRISTIN Plasma levels of nifedipine may be T by qu in upristi n—dalfopristi n Quinupristin inhibits CYP3A4-mediated metabolism of calcium channel blockers Monitor BP closely watch for 1 BP... 

Quinupristin/dalfopristin modestiy increased the AUC of nifedipine. Other calcium-channel blockers are predicted to be similarly affected. 

The manufacturers note that the AUC of repeated-dose nifedipine was increased 1.4-fold by quinupristin/dalfopristin, and the maximum level was increased by 1.18-fold. This is probably because quinupristin/dalfopristin inhibits the cytochrome P450 isoenzyme CYP3A4-mediated metabolism of nifedipine. Although the clinical relevance of these increases have not been assessed, the manufacturers advise blood pressure monitoring and, if necessary, a reduction of nifedipine dosage during concurrent use. It is predicted that other calcium-charmel blockers (e.g. verapamil, diltiazem) will also have their levels raised by quinupristin/dalfopristin. ... 

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