Efavirenz in pregnancy

Clinical guidelines from the National Department of Health (DoH), South Africa, for prevention of mother-tochild transmission (PMTCT), revised in 2010, recommend that HIV-positive pregnant women with a CD4 count of 350 cells/μl or less commence lifelong antiretroviral therapy (ART).¹ DoH guidance for women initiating ART in pregnancy in the public sector – on which the overwhelming majority of HIV-positive South Africans rely for their care – recommends they receive nevirapine with tenofovir and lamivudine or emtricitabine at any stage of gestation. In cases where a woman is already receiving ART with an efavirenz-based regimen, it is recommended that this should be substituted for nevirapine if she is still in the first trimester of pregnancy. Efavirenz is therefore contraindicated in pregnant women at any time during pregnancy; for those already receiving the drug, it is only switched in the first trimester. The concern about the use of efavirenz in pregnancy dates back to preclinical studies. It is the only antiretroviral with preclinical primate data and in turn has the strongest US Food and Drug Administration (FDA) category and the most scrutiny during pregnancy.² The drug also has the most conflicting recommendations, both from guidelines and product labelling. This article is a summary of what we know (and do not know) about using efavirenz in pregnancy. We argue that reconsideration of the risk and benefits of this evidence, which has informed South African guidance, is warranted