Ritonavir Enables Combined Therapy with Rifampin and Saquinavir

Abstract

As recently discussed in this journal, the treatment of individuals coinfected with HIV-1 and Mycobacterium tuberculosis poses a difficult problem for physicians [1]. The current standard of care for the treatment of HIV-1 infection involves a backbone of 2 nucleoside reverse-transcriptase inhibitors in combination with a protease inhibitor or a nonnucleoside reverse transcriptase inhibitor [2]. A dramatic decrease in the systemic exposure of protease inhibitors and nonnucleoside reverse transcriptase inhibitors to subtherapeutic levels has been reported, which can be explained by the inducing effect of rifampin on metabolizing enzymes in the gut wall and liver [1, 3]. This was confirmed in 1 of our patients, who concomitantly used saquinavir and rifampin, as shown in figure 1 (patient 1).