Can I take varenicline while pregnant or breastfeeding?

8.1 Pregnancy Pregnancy Category C. There are no adequate and well-controlled studies of CHANTIX use in pregnant women. In animal studies, CHANTIX caused decreased fetal weights, increased auditory startle response, and decreased fertility in offspring. CHANTIX should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. In reproductive and developmental toxicity studies, pregnant rats and rabbits received varenicline succinate during organogenesis at oral doses up to 15 and 30 mg/kg/day, respectively. These exposures were 36 (rats) and 50 (rabbits) times the human exposure (based on AUC) at the maximum recommended human dose (MRHD) of 1 mg twice daily. While no fetal structural abnormalities occurred in either species, reduced fetal weights occurred in rabbits at the highest dose (exposures 50 times the human exposure at the MRHD based on AUC). Fetal weight reduction did not occur at animal exposures 23 times the human exposure at the MRHD based on AUC. In a pre- and postnatal development study, pregnant rats received up to 15 mg/kg/day of oral varenicline succinate from organogenesis through lactation.

Prescribing label, section “8.1 Pregnancy” (opening excerpt): CHANTIX, Proficient Rx LP. Read the full section on DailyMed. Quoted verbatim; US labels are written for US prescribers and patients.

Varenicline is a partial nicotine agonist used orally to assist smoking cessation and by nasal spray for dry eyes. One researcher points out that based on animal data on nicotine, varenicline might interfere with normal infant lung development and recommends against its use in nursing mothers.[1] Because no information is available on the use of varenicline during breastfeeding, an alternate drug is preferred, especially while nursing a newborn or preterm infant.[2] However, maternal drug exposure after the nasal spray is only about 7.5% that of the oral drug, so the spray is much less likely to affect the infant. If a mother chooses to breastfeed while taking varenicline, she should monitor her infant for seizures and excessive vomiting.[3]

“Summary of Use during Lactation”, LactMed record “Varenicline” (LM784), quoted verbatim. Everything LactMed reports about Varenicline while breastfeeding.

Nursing Mothers It is not known whether CHANTIX is excreted in human milk. In animal studies varenicline was excreted in milk of lactating animals. Because many drugs are excreted in human milk and because of the potential for serious adverse reactions in nursing infants from CHANTIX, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.

Prescribing label, section “Nursing Mothers”: CHANTIX, Proficient Rx LP. Label on DailyMed. Quoted verbatim; US labels are written for US prescribers and patients.