Malaria therapy in HIV: drug interactions between nevirapine and quinine

We report the case of an HIV-positive Nigerian man on antiretroviral therapy (ART) with an undetectable viral load who presented with rigors, fever and back pain after returning to the UK from a three-week trip to Nigeria. Infection with Plasmodium falciparum malaria was confirmed and treatment with quinine commenced together with amoxicillin/clavulanic acid and clarithromycin for possible respiratory infection. At the time of admission the patient could not remember the names of his ART medications. After 24 hours his parasitaemia had increased from 1% to 2.5% and his clinical condition had deteriorated. At this point, his ART was identified as abacavir, lamivudine and nevirapine. The Liverpool HIV-drug interactions website was checked for drug interactions. It recommends caution in the co-administration of both clarithromycin and quinine with nevirapine. Quinine is metabolized by CYP34A and exposure is likely to be decreased by induction of these enzymes in patients taking nevirapine. Given the clinical deterioration the patient was switched to Malarone® (atovoquone/ proguanil) which has no clinically significant interactions with nevirapine. He responded to treatment and was discharged home after 48 hours. This case highlights the importance of knowing the potential drug interactions with ART and the importance of checking for such interactions when prescribing new medications.