Drug reference

Varenicline

Smoking Cessation Aid · Smoking cessation aid

Also known as Champix, CHANTIX

Smoking Cessation AidSmoking cessation aid

CDSCO approvedSchedule H

EXCRETION

—

not curated

INTERACTIONS

—

none in our sources

PREGNANCY

—

not curated

Mechanism

Varenicline is a selective nicotine-receptor partial agonist. It acts as a partial agonist at α4β2 receptors and a full agonist at the α7 subtype, with weak activity toward α3β2- and α6-containing receptors. This action reduces nicotine craving and inhibits the reinforcing effects of nicotine by stimulating α4β2-mediated dopamine release.

Indications

To aid smoking cessation (for smokers who have expressed a desire to quit smoking, normally as part of a programme of behavioural support)nicotine addictionSmoking cessationreduces craving and alcohol consumption (in some studies)Tobacco use disorder treatment

Dosing

Adult: Initially 500 micrograms once daily for 3 days, increased to 500 micrograms twice daily for 4 days, then 1 mg twice daily for 11 weeks; reduced if not tolerated to 500 micrograms twice daily. Usually to be started 1–2 weeks before target stop date but can be started up to a maximum of 5 weeks before target stop date.…
Max dose: 1 mg twice daily

Pharmacokinetics

Bioavailability

High oral bioavailability (~90%)

Protein binding

≤20%

Excretion

Excreted unchanged in the urine

Contraindications

Conditions that may lower seizure threshold
History of cardiovascular disease
History of psychiatric illness (may exacerbate underlying illness including depression)
Predisposition to seizures
Reduce dosage in patients with impaired renal function

Side effects

Common

Appetite abnormalAstheniaChest discomfortConstipationDiarrhoeaDizzinessDrowsinessDry mouthGastrointestinal discomfortGastrointestinal disordersHeadacheJoint disordersMuscle complaintsNauseaMood changesIrrational behaviourAppetite and taste disturbancesSleep disorderAgitation

Serious

Mood and behavioral changes
Exacerbation of underlying psychiatric illness (including depression)
Behavioral or psychiatric changes (e.g., suicide; patients should be monitored and effects typically resolve following discontinuation)
May cause seizures (with alcohol use)
May promote suicidal thoughts