Is Dapivirine safe while breastfeeding?

Summary of use during breastfeeding

Dapivirine is investigational in the United States, but available overseas as a vaginal ring for pre-exposure prophylaxis of HIV infections (PrEP). In this dosage form, it is acceptable to use during breastfeeding. No vaginal dysbiosis was found after use of the dapivirine ring during lactation.[1]

Effects on the breastfed infant

A study compared the dapivirine vaginal ring to emtricitabine plus tenofovir for prophylaxis of HIV infections. Of 148 mother-infant pairs who received the dapivirine vaginal ring, no infants had reports of adverse events attributable to maternal dapivirine therapy.[3]

Effects on milk supply

Relevant published information was not found as of the revision date.

Levels in milk

Maternal Levels. Sixteen lactating women who had weaned their infants used the dapivirine vaginal ring for 14 days and provided milk, blood and cervicovaginal fluid samples for analysis. Milk samples were obtained on days 0, 1, 7 and 14 during use of the insert and on day 16, two days after its removal. The mean breastmilk concentration was 676 ng/L (range 297 to 1,420 ng/L). This translated to an estimated average infant dosage of 74.3 ng/kg daily. The average half-life in milk was 45.8 hours.[2]

A clinical trial compared the dapivirine vaginal ring 25 mg monthly to PrEP consisting of emtricitabine and tenofovir disoproxil fumarate as prophylaxis against HIV infection. In women randomized to dapivirine (n = 148), dapivirine concentrations in breastmilk averaged 682.5 ng/L during the first week of use and trended downward to 664.5 ng/L in the third month of use. At 2 weeks after discontinuation, milk dapivirine averaged 16.7 ng/L.[3]

Infant Levels. A clinical trial compared the dapivirine vaginal ring 25 mg monthly to emtricitabine and tenofovir disoproxil fumarate as prophylaxis against HIV infection. In the infants of women randomized to dapivirine (n = 147), dapivirine was detected in 15% of infants’ serum after 2 weeks of use, but levels were below the level of quantification (<10 ng/L). In the third month of use, the drug was detectable in the serum of only 5%of infants, but below the level of quantification. At 2 weeks after drug discontinuation, no infants had detectable dapivirine in their serum.[3]