Enfuvirtide Rifampicin

The fusion inhibitor, enfuvirtide, is a peptide. It does not eause eyto-chrome P450-mediated drug interactions, and is not affected by potent enzyme inducers (rifampicin) or inhibitors (ritonavir). 

Subcutaneous enfuvirtide 90 mg twice daily for 3 days was given to 12 HIV-positive subjects before, and during, the last 3 days of a 10-day course of rifampicin 600 mg daily. The AUC of enfuvirtide and its metabolite were not significantly altered by rifampicin. ... 

Enfuvirtide is a peptide, and would not be expected to be affected by enzyme inducers such as rifampicin. The findings of this study support this. No special precautions are required during concurrent use. 

Boyd MA, Zhang X, Dorr A, Ruxrungtham K, Kolis S, Nieforth K, Kinchelow T, Buss N, Patel IH. Lack of enzyme-inducing effect of rifampicin on the pharmacokinetics of enfuvirtide. J... 

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