Interactions between diamode(loperamide) and Aptivus (tipranavir)
loperamide and tipranavir (Moderate Drug-Drug)
MONITOR: Coadministration with tipranavir in combination with low-dose ritonavir may decrease the plasma concentrations of loperamide. The mechanism probably involves reduced absorption and increased first-pass clearance of loperamide due to induction of the intestinal P-glycoprotein drug efflux pump by tipranavir. In 24 study subjects, tipranavir/ritonavir (750 mg/200 mg twice a day for 10 days) decreased the mean peak plasma concentration (Cmax) and area under the plasma concentration-time curve (AUC) of loperamide (16 mg single dose) by 61% and 51%, respectively, compared to administration of loperamide without tipranavir/ritonavir. Tipranavir/ritonavir also reduced the Cmax and AUC of the metabolite N-demethyl-loperamide by 79% and 77%, respectively. Tipranavir trough plasma concentration (Cmin) was reduced 26%.
MANAGEMENT: Clinicians and patients should be aware that pharmacologic effects of loperamide may be reduced during coadministration with tipranavir/ritonavir.
