Efavirenz use while Breastfeeding
Drugs containing Efavirenz: Atripla, Sustiva
Efavirenz Levels and Effects while Breastfeeding
Summary of Use during Lactation
In the United States and other developed countries, HIV-infected mothers should generally not breastfeed their infants. Published experience with efavirenz during breastfeeding is limited. In countries in which no acceptable, feasible, sustainable and safe replacement feeding is available, World Health Organization guidelines recommend that all women with an HIV infection who are pregnant or breastfeeding should be maintained on antiretroviral therapy for at least the duration of risk for mother-to-child transmission. Mothers should exclusively breastfeed their infants for the first 6 months of life; breastfeeding with complementary feeding should continue through 12 months of life. The first choice regimen for nursing mothers is tenofovir, efavirenz and either lamivudine or emtricitabine. If these drugs are unavailable, alternative regimens include: 1) zidovudine, lamivudine and efavirenz; 2) zidovudine, lamivudine and nevirapine; or 3) tenofovir, nevirapine and either lamivudine or emtricitabine. Exclusively breastfed infants should also receive 6 weeks of prophylaxis with nevirapine.
Maternal Levels. Thirteen mothers who averaged 15.8 weeks (range 6 to 25 weeks) postpartum were treated with efavirenz 600 mg daily plus zidovudine and lamivudine. Milk and plasma samples were taken 3 to 4 hours after the last dose. Skimmed breastmilk efavirenz concentrations averaged 3.5 mg/L (range 1.3 to 7.4 mg/L).
Infant Levels. Thirteen mothers who averaged 15.8 weeks (range 6 to 25 weeks) postpartum were treated with efavirenz 600 mg daily plus lamivudine and zidovudine (n = 12) or stavudine (n = 1). Plasma samples were taken from their breastfed infants 3 to 4 hours after the last dose. Infant plasma concentrations averaged 0.86 mg/L (range 0.4 to 1.5 mg/L). Infant plasma concentrations averaged 13% of maternal plasma concentrations, but there was no statistically significant correlation between them. Average plasma levels were slightly below the plasma level considered effective for suppression of HIV in adults.
Efavirenz was measured in 117 breastfed (90% exclusive) infants whose mothers were taking efavirenz for HIV infection during pregnancy and postpartum. All infants had detectable efavirenz in their plasma samples at 0 (mean 1.7 mg/L), 8 (mean 0.3 mg/L) and 12 (mean 0.3 mg/L) weeks postpartum. All infants had detectable efavirenz in their hair samples at 12 weeks postpartum at a mean concentration of 1.9 ng/mg of hair (range 0.34 to 11 ng/mg). The authors interpreted the results to mean that infants receive substantial exposure to efavirenz during breastfeeding.
Effects in Breastfed Infants
Thirteen mothers nursed their infants while they were taking efavirenz 600 mg daily, lamivudine 150 mg and zidovudine 300 mg daily (n = 12) or stavudine 60 mg daily (n = 1) . No adverse reactions were reported in the infants after 6 months of breastfeeding, none had developed HIV infection and all were developing normally.
Effects on Lactation and Breastmilk
Gynecomastia has been reported among men and at least one woman receiving efavirenz therapy. Efavirenz appears to be much more likely to cause gynecomastia than other antiretroviral agents. Gynecomastia is unilateral initially, but can progress to bilateral. Spontaneous resolution usually occurred within one year, even with continuation of the regimen. The relevance of these findings to nursing mothers is not known. The prolactin level in a mother with established lactation may not affect her ability to breastfeed.
1. World Health Organization. HIV and infant feeding: update. 2007. http://whqlibdoc.who.int/publications/2007/9789241595964_eng.pdf
2. World Health Organization. Consolidated guidelines on the use of antiretroviral drugs for treating and preventing HIV infection. Geneva: World Health Organization. 2013. http://www.who.int/hiv/pub/guidelines/arv2013/en
3. Schneider S, Peltier A, Gras A et al. Efavirenz in human breast milk, mothers', and newborns' plasma. J Acquir Immune Defic Syndr. 2008;48:450-4. PMID: 18614925
4. Gandhi M, Mwesigwa J, Aweeka F et al. Hair and plasma data show that lopinavir, ritonavir, and efavirenz all transfer from mother to infant in utero, but only efavirenz transfers via breastfeeding. J Acquir Immune Defic Syndr. 2013;63:578-84. PMID: 24135775
5. Jover F, Cuadrado JM, Roig P et al. Efavirenz-associated gynecomastia: report of five cases and review of the literature. Breast J. 2004;10:244-6. PMID: 15125753
6. Rahim S, Ortiz O, Maslow M, Holzman R. A case-control study of gynecomastia in HIV-1-infected patients receiving HAART. AIDS Read. 2004;14:23-4, 29-32, 35-40. PMID: 14959701
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