varenicline CHANTIX

Class: Nicotinic Receptor Partial Agonist
FDA Indications: Smoking Cessation
Off-Label Use:
Forms: 0.5, 1mg tablet
Dose Range: 0.5-2 mg/day
Starting: 0.5 mg qd on days 1-3, then 0.5 mg bid on days 4-7, then 1 mg bid thereafter for a total of 12 weeks

NAMI drug fact sheet

Serious Side Effects: Rare activation of agitation, depressed mood, suicidal ideation, suicidal behavior; may ↓ seizure threshold
Side Effects: nausea (30%), vomiting, constipation, flatulence, insomnia, headache, abnormal dreams, somnambulism
1° MOA: Partial agonist at α4β2 nAChR
Target: α4β2 nAChR, α3β4 nAChR, α6β2 nAChR (partial agonism)
full agonist @ α7 nAChR
t½: 28 (24-33)° TMAX:
Substrate of: Primarily renal; UGT
Inhibits: ∅ ; Induces:
Active Metabolites:
  • - more effective than nicotine replacement or bupropion (varenicline's quit rates are rougly twice that of both)
  • - triples or quadruples the 1-month, 6-month, and 1-year quit rates compared to placebo, though only ~10% of smokers taking varenicline are still abstinent a year later
  • - unlike nicotine or bupropion, the patient cannot "smoke over" varenicline since varenicline, but not others, will block the effects of additional smoked nicotine if the patient decides to smoke during the treatment
Special Populations

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


Developed & Designed by Kevin M. Nasky, D.O. • Built with Bootstrap, PHP & MySQL • Hosted by SiteGround
Last updated February 29 2024 20:54:18. Disclaimer: This website does not provide medical advice, nor is it a substitute for clinical judgment.