Antiretroviral therapy and malaria

Most of the HIV protease inhibitors also have anti-malarial activity, possibly at similar concentrations to their anti-HIV activity.¹ While this may seem promising for the treatment of HIV and malaria concurrently, the protease inhibitors not yet been shown to have any clinical impact on malaria and are still not commonly used in malaria-endemic areas due to their cost. However, antiretroviral therapy can reduce rates of malaria infection, due to its positive effects on the immune system.²

There are a number of potential drug interactions between anti-malarial and anti-HIV drugs. For example, ritonavir (Norvir) and ritonavir-boosted lopinavir (Kaletra) may boost levels of quinine or lumefantrine, perhaps to dangerous levels. In contrast, non-nucleoside reverse transcriptase inhibitors (NNRTIs) such as nevirapine (Viramune) may lower the concentrations and effectiveness of these drugs. Protease inhibitors or NNRTIs may also affect the balance between artemether and its metabolites, but data are still limited and any clinical implications are unclear.³

Drug toxicity could also complicate the clinical management of HIV and malaria. For example, a common side effect of AZT (zidovudine, Retrovir) is anaemia, which is of concern in patients who are anaemic due to malaria. Another issue is the convergent toxicity of nevirapine (Viramune)-based antiretroviral therapy and pyrimethamine with sulfadoxine, particularly in pregnant women who are taking or have taken intermittent preventative therapy: hypersensitivity reactions to nevirapine, including potentially fatal liver and skin reactions, are indistinguishable from similar reactions to pyrimethamine with sulfadoxine.⁴