Publication Date:
2014-12-31
Description:
Background Pregnancy and tuberculosis treatment or prophylaxis can affect efavirenz pharmacokinetics, maternal human immunodeficiency virus type 1 (HIV-1) treatment outcomes, and mother-to-child transmission (MTCT) risk. Methods We evaluated a prospective cohort of pregnant, HIV-infected women with and without tuberculosis in Soweto, South Africa. Pharmacokinetic sampling was performed at gestation week 37 and during the postpartum period . Efavirenz trough concentrations (C min ) were predicted using population pharmacokinetic models. HIV-viral load was measured at delivery for mothers and at 6 weeks of age for infants. Results Ninety-seven women participated; 44 had tuberculosis. Median efavirenz C min during pregnancy was 1.35 µg/mL (interquartile range [IQR], 0.90–2.07 µg/mL; 27% had an efavirenz C min of 〈 1 µg/mL), compared with a median postpartum value of 2.00 µg/mL (IQR, 1.40–3.59 µg/mL; 13% had an efavirenz C min of 〈 1 µg/mL). A total of 72% of pregnant women with extensive CYP2B6 genotypes had an efavirenz C min of 〈1 µg/mL. Rifampin did not reduce the efavirenz C min . Isoniazid (for prophylaxis or treatment), though, reduced the rate of efavirenz clearance. At delivery, median durations of ART were 13 weeks (IQR, 9–18 weeks) and 21 weeks (IQR, 13–64 weeks) for women with and those without tuberculosis, respectively; 55% and 83%, respectively, had a viral load of 〈20 copies/mL ( P = .021). There was 1 case of MTCT. Conclusions Pregnancy increased the risk of low efavirenz concentrations, but MTCT was rare. A detectable HIV-viral load at delivery was more common among pregnant women with tuberculosis, in whom ART was generally initiated later.
Print ISSN:
0022-1899
Electronic ISSN:
1537-6613
Topics:
Medicine
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