Emtricitabine has been relatively well studied during breastfeeding and it is sometime used in treating HIV-positive mothers who are breastfeeding. 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]
For use in treating maternal hepatitis B, no difference exist in infection rates between breastfed and formula-fed infants born to hepatitis B-infected women, as long as the infant receives hepatitis B immune globulin and hepatitis B vaccine at birth. Mothers with hepatitis B are encouraged to breastfeed their infants after their infants receive these preventative measures.[3,4] With HIV pre-exposure prophylaxis with tenofovir 200 mg and emtricitabine 300 mg, infants receive only about 0.5% of a therapeutic dose of emtricitabine. During long-term maternal use of emtricitabine 200 mg daily, breastfed infants usually have undetectable blood concentrations.