Is Vanzacaftor, Tezacaftor and Deutivacaftor safe while breastfeeding?
Here is what NIH LactMed, the U.S. National Library of Medicine's authority on medicines and breastfeeding, reports about Vanzacaftor, Tezacaftor and Deutivacaftor. This is a summary of that source — not our own verdict.
Effects on the breastfed infant
Relevant published information on the combination of vanzacaftor, tezacaftor and deutivacaftor was not found as of the revision date. Information on other partially overlapping combination products is listed below. An infant was born to a mother taking elexacaftor, ivacaftor and tezacaftor for cystic fibrosis. The infant was breastfed (extent not stated). Although the infant had cystic fibrosis-causing CFTR mutations, the infant was healthy and tested negative for cystic fibrosis on newborn screening. The authors expressed concern that the drugs received transplacentally and in breastmilk caused a false negative screening test.[ 8 ] A mother who was a heterozygous carrier of the F508del gene became pregnant with a homozygous infant. At 32 weeks of pregnancy, the mother began elexacaftor, ivacaftor and tezacaftor in the usual adult dosage to treat her fetus who had evidence of meconium ileus. The infant was born at 36 weeks and given pancreatic enzyme replacement therapy with breastfeeding while maternal treatment continued. The infant s fecal elastase, transaminases and bilirubin were normal at about 1 month of age. The infant s sweat chloride, although low, was nearer to normal than was expected. The authors hypothesized that the medications received in breastmilk moderated the disease process in the infant.[ 9 ] Three women with cystic fibrosis were taking elexacaftor, ivacaftor and tezacaftor in unspecified dosages during pregnancy and postpartum while breastfeeding. On routine visual examinations between 8 days and 6 months postpartum, their infants were found to have small ( 1.0 mm) bilateral cataracts, in the central area in one and outside the visual axis in the other two. Breastfeeding was discontinued after diagnosis at 16 days, 9 weeks and 6 months postpartum. The contribution of breastfeeding to the cataracts could not be determined.[ 5 ] A woman with cystic fibrosis began elexacaftor, ivacaftor and tezacaftor prior to conception and continued it througho
Effects on milk supply
Relevant published information was not found as of the revision date.
Levels in milk
Deutivacaftor is a deuterated form of ivacaftor that has slower clearance and a longer half-life.[ 3 ] At recommend adult dosages, exposure to deutivacaftor is about 67% greater than with usual dosages of ivacaftor in a similar 3-drug combination product. Milk levels of deutivacaftor are probably increased by about the same amount, but no studies on milk excretion of deutivacaftor or on vanzacaftor have been reported. Information on ivacaftor can be found in the ivacaftor record and tezacaftor information is reported below. Maternal Levels. Two nursing mothers with cystic fibrosis who were taking elexacaftor, ivacaftor and tezacaftor, had their milk samples analyzed 2 or 3 times between 15 and 60 days postpartum. The tezacaftor milk level was 1 micromolar in one woman at 15 and 60 days postpartum. The other woman had a tezacaftor milk level of 1 micromolar at 30 and 45 days postpartum. Milk levels tended to increase slightly over time.[ 4 ] Two nursing mothers with cystic fibrosis were taking elexacaftor, ivacaftor and tezacaftor in unspecified dosages. The tezacaftor concentration in milk at unreported times after a dose was 0.12 micromolar (62.5 mcg/L) and 0.39 micromolar (203 mcg/L).[ 5 ] A woman with cystic fibrosis received elexacaftor 100 mg, tezacaftor, 50 mg, ivacaftor 75 mg and additional ivacaftor 150 mg daily while exclusively breastfeeding her 3-month-old infant. Fasting breastmilk samples were collected just before the morning dose of elexacaftor, tezacaftor, and ivacaftor. The tezacaftor concentration in milk was 761 mcg/L.[ 6 ] Infant Levels. Two partially breastfed (extent not stated) infants whose mothers were taking elexacaftor, ivacaftor and tezacaftor had serum drug concentrations measured several times. Tezacaftor levels were highest of the 3 drugs, starting at about 1 micromolar at birth. Levels remained similar in one infant up to 100 days of age and dropped below 1 micromolar at 45 and 60 days postpartum in the other.[ 4 ] A woman with cystic
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.