Varenicline Tartrate

What it is and how it works

Mechanism of Action Varenicline binds with high affinity and selectivity at α4β2 neuronal nicotinic acetylcholine receptors. The efficacy of varenicline 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.

Indications

Varenicline tablets are indicated for use as an aid to smoking cessation treatment. Varenicline tablets are a nicotinic receptor partial agonist indicated for use as an aid to smoking cessation treatment. ( 1 and 2.1 )

Dosage and administration (summary)

Begin varenicline tablets dosing one week before the date set by the patient to stop smoking. Alternatively, the patient can begin varenicline tablets dosing and then quit smoking between days 8 and 35 of treatment. Starting Week: 0.5 mg once daily on days 1 to 3 and 0.5 mg twice daily on days 4 to 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 varenicline tablets for patients who are sure that they are not able or willing to quit abruptly.

Contraindications

Varenicline tablets are contraindicated in patients with a known history of serious hypersensitivity reactions or skin reactions to varenicline tablets. History of serious hypersensitivity or skin reactions to varenicline tablets.

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. Observe patients attempting to quit smoking with varenicline for the occurrence of such symptoms and instruct them to discontinue varenicline and contact a healthcare provider if they experience such adverse events.

Pregnancy

Pregnancy Risk Summary 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) .

Storage and supply

Varenicline tablets are supplied for oral administration in two strengths: 0.5 mg are capsular, biconvex, white, film-coated tablets debossed with ‘VA’ on one side and ‘0.5’ on the other side. 1 mg are capsular, biconvex, light blue, film-coated tablets debossed with ‘VA’ on one side and ‘1’ on the other side.

Source: Varenicline (Varenicline) — US FDA prescribing information, 2025-05-08, DailyMed. Summarised and shortened; the full label governs. Iranian registration, indications and labelling may differ.