Is Efavirenz safe while breastfeeding?
Here is what NIH LactMed, the U.S. National Library of Medicine's authority on medicines and breastfeeding, reports about Efavirenz. This is a summary of that source — not our own verdict.
Effects on the breastfed infant
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.[ 3 ] An unblinded study in Uganda compared the outcomes of breastfed infants and their HIV-positive mothers who were randomized to receive antiretroviral therapy that was based either on efavirenz 600 mg once daily or lopinavir 400 mg plus ritonavir 100 mg twice daily during breastfeeding. All mothers received lamivudine 150 mg, zidovudine 300 mg twice daily and trimethoprim-sulfamethoxazole once daily. All infants received prophylaxis with either zidovudine for 1 week or nevirapine for 6 weeks, plus trimethoprim-sulfamethoxazole from 6 weeks of age to 6 weeks after weaning. Almost all of the infants were exclusively breastfed until 6 months of age and about 73% were partially breastfed until 12 months of age. There was no statistical difference in hospitalizations or adverse events including anemia, neutropenia or deaths among infants in the two groups.[ 12 ] Among 32 breastfed (extent not stated) infants whose mothers were taking efavirenz 600 mg daily as part of a multi-drug treatment for HIV infection, no adverse effects were noted by investigators or reported by mothers at 1, 3 and 6 months of age.[ 9 ] A prospective cohort study in Malawi compared the infants of HIV+ mothers taking efavirenz and tenofovir disoproxil fumarate (n = 260) to infants of mothers who were HIV negative (n = 125). Infants were followed for growth and development for up to 18 months at which time there were 169 mother-infant pairs in the treatment group and 54 in the HIV-negative group. No difference was found in the growth and development of the breastfed infants of treated women compared to the infants of untreated mothers.[ 13 ] An open-label, controlled, multicent
Effects on milk supply
Gynecomastia has been reported among men and at least one woman receiving efavirenz therapy.[ 15 , 16 ] 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.
Levels in milk
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).[ 3 ] Five mothers who were taking oral efavirenz 600 mg daily as part of an antiretroviral regimen collected mid-feed milk samples at 0.5, 1, 2, 4, 8, 12 and 24 hours after an evening dose at an average of 146 days after delivery. The average peak level of 4.5 mg/L occurred at about 4 hours after the dose and the average trough milk value was 2.5 mg/L.[ 4 ] One hundred thirty-four mothers who were taking efavirenz 600 mg at bedtime as part of their antiretroviral regimen and their infants were studied. In the first part of the study, women were separated into noncarriers, homozygotes and homozygotes for the CYP2B6 516TT gene. Random breastmilk concentrations had median values of 1610, 2370 and 4070 mcg/L in the three groups, respectively. A pooled subset of 29 mothers underwent extensive sampling of plasma and breastmilk sampling, encompassing 203 paired maternal plasma and breastmilk levels. In these mothers the median peak breastmilk levels were 4020 4540 and 8920 mcg/L, respectively. Corresponding trough milk levels were 1120, 1500, and 2480 mcg/L. The authors estimated that the average dosages that infants would receive would be 344 mcg/kg, 379 mcg/kg and 1340 mcg/kg daily in the maternal noncarrier, heterozygous and homozygous groups, respectively.[ 5 ] A physiologically based pharmacokinetic model was created by the authors and compared to the 29 pooled patients data. Over 80% of observed data points were within the model s predictive interval.[ 6 ] Another model based on data from this study found that the simulated average milk concentrations were 2.31 mg/L, 2.89 mg/L and 4.63 mg/L from CYP2B6 516GG, GT, and TT mothers, respectively. These tran
Source: NIH LactMed (National Library of Medicine).
Educational summary of an authoritative source — not medical advice. Never start, stop, or change a medicine while breastfeeding without confirming with your doctor.