Varenicline

Chantix

Approved uses

• CHANTIX is a nicotinic receptor partial agonist indicated for use as an aid to smoking-cessation treatment.

Forms and strengths

• Capsular, biconvex tablets: 0.5 mg (white to off-white, debossed with " Pfizer " on one side and "CHX 0.5" on the other side) and 1 mg (light blue, debossed with " Pfizer " on one side and "CHX 1.0"...
• Tablets: 0.5 mg and 1 mg

How it is taken

• Begin CHANTIX dosing one week before the date set by the patient to stop smoking. Alternatively, the patient can begin CHANTIX dosing and then quit smoking between days 8 and 35 of treatment.
• Starting Week: 0.5 mg once daily on days 1-3 and 0.5 mg twice daily on days 4-7.
• Continuing Weeks: 1 mg twice daily for a total of 12 weeks.
• An additional 12 weeks of treatment is recommended for successful quitters to increase likelihood of long-term abstinence.
• Consider a gradual approach to quitting smoking with CHANTIX for patients who are sure that they are not able or willing to quit abruptly. Patients should begin CHANTIX dosing and reduce smoking by 50% from baseline within the first four weeks, by an additional 50% in the next four weeks, and continue reducing with the goal of reaching complete abstinence by 12 weeks.
• Severe Renal Impairment (estimated creatinine clearance less than 30 mL/min): Begin with 0.5 mg once daily and titrate to 0.5 mg twice daily. For patients with end-stage renal disease undergoing hemodialysis, a maximum of 0.5 mg daily may be given if tolerated.

Must not be used when

• CHANTIX is contraindicated in patients with a known history of serious hypersensitivity reactions or skin reactions to CHANTIX.
• History of serious hypersensitivity or skin reactions to CHANTIX.

Interactions

• Other Smoking-Cessation Therapies: Safety and efficacy in combination with other smoking-cessation therapies has not been established. Coadministration of varenicline and transdermal nicotine resulted in a high rate of discontinuation due to adverse events.
• Effect of Smoking Cessation on Other Drugs: Pharmacokinetics or pharmacodynamics of certain drugs (e.g., theophylline, warfarin, insulin) may be altered, necessitating dose adjustment. Use with Other Drugs for Smoking Cessation Safety and efficacy of CHANTIX in combination with other smoking cessation therapies have not been studied.

Warnings and precautions

• Neuropsychiatric Adverse Events: Postmarketing reports of serious or clinically significant neuropsychiatric adverse events have included changes in mood (including depression and mania), psychosis, hallucinations, paranoia, delusions, homicidal ideation, aggression, hostility, agitation, anxiety, and panic, as well as suicidal ideation, suicide attempt, and completed suicide.
• Seizures: New or worsening seizures have been observed in patients taking CHANTIX. CHANTIX should be used cautiously in patients with a history of seizures or other factors that can lower the seizure threshold.
• Interaction with Alcohol: Increased effects of alcohol have been reported. Instruct patients to reduce the amount of alcohol they consume until they know whether CHANTIX affects them.
• Accidental Injury: Accidental injuries (e.g., traffic accidents) have been reported. Instruct patients to use caution driving or operating machinery until they know how CHANTIX may affect them.
• Nausea: Nausea is the most common adverse reaction (up to 30% incidence rate). Dose reduction may be helpful. Neuropsychiatric Adverse Events including Suicidality Serious neuropsychiatric adverse events have been reported in patients being treated with CHANTIX.

Common side effects

• most common adverse events associated with CHANTIX (>5% and twice the rate seen in placebo-treated patients) were nausea, abnormal (vivid, unusual, or strange) dreams, constipation, flatulence, and vomiting.
• most common adverse events in CHANTIX-treated patients were as follows: nausea (3% vs.
• most common adverse event associated with CHANTIX treatment is nausea, occurring in 30% of patients treated at the recommended dose, compared with 10% in patients taking a comparable placebo regimen.

Pregnancy

Available data have not suggested an increased risk for major birth defects following exposure to varenicline in pregnancy, compared with women who smoke. Smoking during pregnancy is associated with maternal, fetal, and neonatal risks (see Clinical Considerations).

How it acts

Varenicline binds with high affinity and selectivity at α4β2 neuronal nicotinic acetylcholine receptors. The efficacy of CHANTIX in smoking cessation is believed to be the result of varenicline's activity at α4β2 sub-type of the nicotinic receptor where its binding produces agonist activity, while simultaneously preventing nicotine binding to these receptors. Electrophysiology studies in vitro and neurochemical studies in vivo have shown that varenicline binds to α4β2 neuronal nicotinic acetylcholine receptors and stimulates receptor-mediated activity, but at a significantly lower level than nicotine.

Label holder:

Pfizer Laboratories Div Pfizer Inc

Label version:

23 January 2026

This section reports the approved product information. The wording is condensed from the regulator's own summary, and the full document is linked under Sources.