Category Undefined.—Limited data in human pregnancy. There were some adverse outcomes but their relationship to the drug is unknown. Animal data suggests low risk, but the limited human pregnancy experience prevents a better assessment of the embryo-fetal risk. However, smoking is known to cause significant developmental toxicity. Thus, the benefit to the woman and her pregnancy appears to outweigh the unknown risk to the embryo and/or fetus. If nonpharmacologic methods to stop smoking have failed, and the use of varenicline is indicated, it should not be withheld because of pregnancy.
No reports describing the use of varenicline during human lactation have been located. The molecular weight, high oral bioavailability, low metabolism and plasma protein binding (≤ 20%), and the long t½ suggest that the drug will be excreted into breast milk. The effects of this exposure on a nursing infant are unknown.
No dosage adjustment is recommended for elderly patients.
Severe Renal Impairment (~CrCl < 30 mL/min): begin with 0.5 mg qd and titrate to 0.5 mg bid. For patients with ESRD undergoing hemodialysis, a maximum of 0.5 mg qd may be given if tolerated.
Dose adjustment not generally necessary