Effect of efavirenz on day 7 plasma lumefantrine concentration during coinfection of plasmodium sp. and HIV-1 in Cameroonians adults

ETOUNDI A NWAGA VALERIE AGNES (lexievale@gmail.com)
toxicology and pharmacology, faculty of medecine and biomedical sciences
June, 2016


Background: The antiretroviral triple therapy containing efavirenz and antimalarial
artemisinin-based combination therapy artemether/lumefantrine are commonly coadministered
to treat HIV infection and malaria. Efavirenz is a known inducer of cytochrome
P450 3A4, and artemether/lumefantrine are metabolized by this enzyme. This predisposes
patients to poor treatment response and the risk of developing resistances. We evaluated
the effect of efavirenz on day 7 plasma lumefantrine concentration during co-infection of
plasmodium sp. and HIV-1 in Cameroonians adults.

Methods: it was an open-labeled, parallel, non-randomized clinical study with two groups.
Group 1: HIV positive adults on EFV. Group 2: HIV negative adults not on EFV. Both groups
received 80/480mg AL BID for three days and venous blood was sampled 7 days after the
start of treatment. We determined plasma lumefantrine concentration with and without the
presence of efavirenz.
Results: Sixty participants consisting of 30 HIV-1 positive and 30 HIV-1 negative participants
all with microscopically confirmed plasmodium species infections were enrolled in the study.
Lumefantrine concentration on day 7 was significantly lower in HIV positive participants than
in HIV negative participants (31.6% lower) with P= 0.0001.

Conclusion: Exposure of lumefantrine was significantly lower during efavirenzartemether/
lumefantrine co-administration compared to that during administration of
artemether/lumefantrine alone.

Keywords: efavirenz, artemether, lumefantrine, drug exposure.