Bictegravir and Breastfeeding

Summary of use during lactation

Limited information indicates that maternal bictegravir 50 mg once daily produce low levels in milk and infant serum. Until more data become available, an alternate drug may be preferred, especially while nursing a newborn or preterm infant. Achieving and maintaining viral suppression with antiretroviral therapy decreases breastfeeding transmission risk to less than 1%, but not zero. Individuals with HIV who are on antiretroviral therapy with a sustained undetectable viral load and who choose to breastfeed should be supported in this decision. If a viral load is not suppressed, banked pasteurized donor milk or formula is recommended.[1,2]

Drug levels in milk and infant serum

Maternal Levels. A mother taking bictegravir 50 mg once daily provided 3 milk samples at a median of 8.5 hours after a dose. The median drug concentration in milk was 57 mcg/L, which resulted in an estimated infant dosage of 10 mcg/kg daily.[3] Twelve healthy lactating volunteers took a single 50 mg dose of bictegravir in a combination product that also contained emtricitabine 200 mg and tenofovir alafenamide 25 mg (Biktarvy). Milk samples were taken before the dose and 2, 4, 6, 12 and 24 hours after the dose. The median daily infant dosage was 0.046 mg/kg and the RID was 0.90%.[4] Infant Levels. An infant was breastfed by a mother taking bictegravir 50 mg once daily, although the extent of breastfeeding was not sated. The infant’s serum concentrations taken 19 hours after maternal drug intake at 1 month of age was 103 mcg/L.[3]

Effects in breastfed infants

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

Effects on lactation and breastmilk

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.[5-7] Some case reports and in vitro studies have suggested that protease inhibitors might cause hyperprolactinemia and galactorrhea in some male patients,[8,9] although this has been disputed.[10] 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.

Alternative drugs to consider

Raltegravir

References

1. Department of Health and Human Services. Recommendations for the use of antiretroviral drugs during pregnancy and interventions to reduce perinatal HIV transmission in the United States. 2024 https://clinicalinfo.hiv.gov/sites/default/files/guidelines/documents/perinatal-hiv/guidelines-perinatal.pdf
2. World Health Organization. Consolidated guidelines on HIV prevention, testing, treatment, service delivery and monitoring: Recommendations for a public health approach. 2021 https://www.who.int/publications/i/item/9789240031593 PubMed
3. Aebi-Popp K, Kahlert CR, Crisinel PA, et al. Transfer of antiretroviral drugs into breastmilk: A prospective study from the Swiss Mother and Child HIV Cohort Study. J Antimicrob Chemother 2022;77:3436–42.36177836 PubMed
4. Van Der Wekken-Pas L, Burger D, Colbers A. Pharmacokinetic parameters of bictegravir in breastmilk of healthy, lactating volunteers without HIV after a single dose of 50 mg (co-formulated with emtricitabine 200 mg and tenofovir alafenamide 25 mg). Br J Clin Pharmacol 2025;91:7. doi:10.1002/bcp.70207
5. García-Benayas T, Blanco F, Martin-Carbonero L, et al. Gynecomastia in HIV-infected patients receiving antiretroviral therapy. AIDS Res Hum Retroviruses 2003;19:739–41.14585204 PubMed
6. Pantanowitz L, Evans D, Gross PD, et al. HIV-related gynecomastia. Breast J 2003;9:131–2.12603389 PubMed
7. Evans DL, Pantanowitz L, Dezube BJ, et al. Breast enlargement in 13 men who were seropositive for human immunodeficiency virus. Clin Infect Dis 2002;35:1113–9.12384846 PubMed
8. Hutchinson J, Murphy M, Harries R, et al. Galactorrhoea and hyperprolactinaemia associated with protease-inhibitors. Lancet 2000;356:1003–4.11041407 PubMed
9. Orlando G, Brunetti L, Vacca M. Ritonavir and saquinavir directly stimulate anterior pituitary prolactin secretion, in vitro. Int J Immunopathol Pharmacol 2002;15:65–8.12593790 PubMed
10. Montero A, Bottasso OA, Luraghi MR, et al. Galactorrhoea, hyperprolactinaemia, and protease inhibitors. Lancet 2001;357:473–5.11273087 PubMed