The 25% reduction of median NVP concentrations observed among women receiving MQ compared with placebo is similar to other known interactions of MQ with other drugs, including reduction of the ARV ritonavir and rifampicin for tuberculosis treatment.9,10 The potential for MQ and NVP to alter concentrations of each other has been previously speculated, namely because both drugs are metabolized by cytochrome P450 3A4 (CYP3A4),11 yet concerns have primarily focused on NVP reducing MQ efficacy rather than the converse. This evidence concerns the gene CYP3A4 and tuberculosis.