Table 2.

Drug interactions between CQ/HCQ and antituberculous or antiretroviral therapies

Medicine	Potential interaction with CQ/HCQ
Efavirenz	Limited clinical data. May increase (inhibition of CYP2C8) or decrease (induction of CYP3A4) exposure. Concurrent use may increase the risk of QT interval prolongation.
Lopinavir/ritonavir or atazanavir/ritonavir	Limited clinical data. May increase exposure by inhibition of CYPs 2C8, 3A4, and 2D6. Concurrent use may increase the risk of QTc interval prolongation.
Rifampicin	Limited clinical data. Induces phase-I and phase-II enzymes and transporters. Induction of CYP3A4 may decrease CQ/HCQ exposure.
Levofloxacin and moxifloxacin	Concurrent use may increase the risk of QTc interval prolongation.
Bedaquiline	Concurrent use may increase the risk of QTc interval prolongation.

CQ = chloroquine; HCQ = hydroxychloroquine. The metabolism of HCQ and CQ is predominantly mediated by the hepatic cytochrome P450 (CYP) enzymes 3A4 and 2D6, but 2C8 and 3A5 are also important. Any drug that induces or inhibits these CYP enzymes may potentially alter CQ/HCQ concentrations.^37–44