Varenicline

Other CNS Drugs · Selective nicotine receptor partial agonist

Indications

For smoking cessation.

Dosage

Adults: Start 1-2 wk before target stop date, initially 500 mcg once daily for 3 days, increased to 500 mcg twice daily for 4 days then 1 mg twice daily for 11 wk (reduce to 500 mcg twice daily if not tolerated); 12 wk course can be repeated in abstinent individuals to reduce risk of relapse. Children: Not recommended.

Adverse Effects

Abnormal dreams, insomnia, headache, nausea, increased appetite, somnolence, dizziness, dyspepsia, GI disturbances, fatigue, wt gain, dysgeusia, dry mouth, toothache, dyspnoea, cough, rash, pruritus, arthralgia, myalgia, back and chest pain, abnormal LFTs, RTI. Angioedema and serious skin reactions. Depression and suicidal ideation.

Risk Factor (Pregnancy/Lactation)

Pregnancy: Contraindicated in pregnancy. Lactation: Caution advised or effect undetermined. Contraindications: End-stage renal disease. Precautions: History of psychiatric illness. May impair ability to drive or operate machinery. Severe renal impairment. Re-evaluate treatment if serious neuropsychiatric symptoms occur. Cardiovascular symptoms, MI or stroke. Epilepsy. Risk of irritability, urge to smoke, depression and insomnia after stopping treatment.

Interactions

Theophylline, warfarin, insulin, other drug metabolized by CYP1A2. Cimetidine, clozapine, ropinirole.

Advice to Patient

Take after meals with a full glass of water. Set a date to stop smoking and then start taking medication 1 week before the stop date. Continue trying to stop smoking even if an early relapse occurs during therapy. Contact prescriber if there is change in behaviour, agitation, depression, abnormal thoughts, skin rash, difficulty in breathing, nausea, swelling on face/mouth/limbs/neck. On start of therapy or change of dosage, patient should be watched carefully for suicidal tendency by caregiver or family.

Pharmacokinetics

Absorption: Well absorbed; unaffected by food. Metabolism: Minimal. Bioavailability: Approx. 90%. Half-life elimination: Approx. 24 hours. Time to peak, plasma: Approx. 3 to 4 hours. Excretion: Urine (92% as unchanged drug).

Compiled by Healify Pharmacy from published drug references. How we compile it →

Always consult a pharmacist or doctor.