Sildenafil does not alter nelfinavir pharmacokinetics

The objective of this study was to investigate if sildenafil influences the pharmacokinetics of nelfinavir. Five HIV-infected patients on steady-state nelfinavir-containing therapy were subject to pharmacokinetic sampling for nelfinavir concentration twice: without sildenafil and with sildenafil 25 mg as a single dose. There were no differences in the AUC, T(max), or C(max) of nelfinavir. In a similar design, two patients on indinavir and two patients on ritonavir combined with saquinavir were studied. In accordance with the literature, neither of these two treatments was affected. It is concluded that nelfinavir pharmacokinetics were unaffected by concomitant intake of a single dose of sildenafil.