Tipranavir: new drug. HIV protease inhibitor. A last resort

(1) Despite the availability of multidrug antiretroviral therapies, about 3% to 4% of HIV-infected patients exhaust nearly all available treatment options. (2) Tipranavir, an HIV protease inhibitor, is marketed in France for patients with multidrug resistance. (3) Two randomised unblinded trials are currently comparing the tipranavir + ritonavir combination with other protease inhibitors as adjuncts to optimised antiretroviral treatment in 1159 patients selected on the basis of laboratory criteria. Interim results at 48 weeks show that significantly more patients have an undetectable viral load with tipranavir + ritonavir than with other protease inhibitors (22.8% versus 10.2%). Enfuvirtide co-administration seems to reinforce the effect of tipranavir + ritonavir. In contrast, tipranavir does not seem to be more effective than other HIV protease inhibitors to which a given patient's viral population remains sensitive. (4) Tipranavir seems to be associated with higher risks of hepatic disorders, hypertriglyceridaemia, hypercholesterolaemia, and potentially severe bleeding than other protease inhibitors. (5) Tipranavir inhibits the activity of most cytochrome P450 isoenzymes. This creates a strong potential for drug interactions, but clinical experience is limited. (6) Patients on tipranavir must take 2 capsules twice a day. (7) In practice, tipranavir should be saved as a last-resort HIV protease inhibitor.