Is Lamivudine safe while breastfeeding?
Here is what NIH LactMed, the U.S. National Library of Medicine's authority on medicines and breastfeeding, reports about Lamivudine. This is a summary of that source — not our own verdict.
Effects on the breastfed infant
A study assigned pregnant women to zidovudine alone or highly active antiretroviral therapy (HAART: zidovudine, lamivudine and nevirapine) to prevent maternal-to-child transmission of HIV infection. After delivery, all infants received one month of zidovudine prophylaxis; some infants were breastfed and others were formula fed. A higher percentage of infants in the HAART-exposed group had neutropenia than those in the unexposed group at 1 month of age (15.9% and 3.7%, respectively). Hematologic toxicity was transient and asymptomatic. From 2 to 6 months postpartum, no differences in hematologic toxicity were seen between breastfed and formula-fed infants. No statistical difference in hepatic toxicity was seen between the breastfed and formula-fed infants.[ 26 ] Twenty-four infants who were breastfed by HIV-positive mothers developed HIV infection by 6 months of age. Six of these infants had a mutation that might have been selected for by subtherapeutic levels of lamivudine in breastmilk.[ 27 ] An HIV-positive mother took a combination tablet containing dolutegravir 50 mg, abacavir sulfate 600 mg and lamivudine 300 mg (Triumeq) once daily. Her infant was exclusively breastfed for about 30 weeks and partially breastfed for about 20 weeks more. No obvious side effects were noted.[ 28 ] One mother took lamivudine for 33 days, 25 before birth and eight days postpartum for chronic hepatitis B infection. Her infant was breastfed (extent not stated). At three months of age, the infant died with the death attributed to sudden infant death syndrome. The death was unlikely to be related to lamivudine.[ 29 ] A woman with newly diagnosed HIV infection began dolutegravir 50 mg and lamivudine 300 mg daily at week 23 of pregnancy. She breastfed (extent not stated) her infant who remained HIV-negative after 10 month of breastfeeding and had normal growth- and neurological development.[ 30 ]
Effects on milk supply
Gynecomastia has been reported among men receiving highly active antiretroviral therapy. Gynecomastia is unilateral initially, but progresses to bilateral in about half of cases. No alterations in serum prolactin were noted and spontaneous resolution usually occurred within one year, even with continuation of the regimen.[ 31 - 33 ] Some case reports and in vitro studies have suggested that protease inhibitors might cause hyperprolactinemia and galactorrhea in some male patients,[ 34 , 35 ] although this has been disputed.[ 36 ] 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. Milk samples were taken daily before breastfeeding from 2 groups of women receiving lamivudine, one on monotherapy and the other on combination therapy. In the group receiving lamivudine 300 mg twice daily (n = 10), the average milk concentration was 1.2 mg/L (range 0.5 to 6.1 mg/L). In the group receiving 150 mg twice daily plus zidovudine (n = 10), the average milk lamivudine concentration was 0.9 mg/L (range 0.5 to 8.2 mg/L).[ 10 ] Twenty women who were receiving oral lamivudine 150 mg twice daily as part of a combination antiretroviral regimen had their milk analyzed at either 2 or 5 months postpartum. Milk samples were provided at a median of 4 hours (range 1 to 8.5 hours) after the last dose. The median lamivudine concentration in breastmilk was 1.8 mg/L.[ 11 ] Forty women were given postpartum prophylaxis with unstated dosages of lamivudine, nevirapine, and zidovudine (or stavudine if the hemoglobin 8 g/dL). Blood and milk samples were collected once during the first 3 days postpartum and once at 7 days postpartum. The median times after a dose that samples were collected were 5.3 hours (range 0 to 99 hours) for the first sample and 6 hours (range 4.3 to 20 hours) for the 7-day sample. Average breastmilk lamivudine concentrations were calculated only for samples that had detectable ( 20 mcg/L) concentrations of lamivudine. The mean breastmilk concentrations were 0.4 (n = 9) and 0.4 mg/L (n = 30), respectively, at the two sampling times, which was 2.9 to 3.3 times the simultaneous maternal serum concentrations.[ 12 ] Forty-seven samples of breastmilk and maternal serum were obtained at 6, 12 and 24 weeks postpartum from mothers taking lamivudine as part of a combination of antiretrovirals. The lamivudine dosage the mothers were taking was not stated in the abstract. The median breastmilk concentrations of lamivudine at a median of 14 hours after the last maternal dose were 510 (17 samples), 387 (17 samples) and 310 mcg/L (13 samples). Median m
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.