Varenicline

Nicotinic Partial Agonist·Addiction Medicine

Smoking cessation in adults

PBSPBS streamlinedSMOKINGChampix0.5 mg tablet+2

Max Dose

1 mg BD

Half-life

24 h

Nausea

COMMON

Neuropsych Risk

MONITOR

Rapid Summary

Overview

Selective alpha-4-beta-2 nicotinic receptor partial agonist used as an aid to smoking cessation in adults. It reduces withdrawal/craving and blunts nicotine reward if smoking occurs.

Maximum Dose

Max 2 mg/day (1 mg BD).

Clinical Focus

Use varenicline with a quit plan and behavioural support. Monitor for serious mood, behaviour, suicidal-ideation, seizure, and tolerability problems; do not present EAGLES or any single trial as proving universal psychiatric safety.

Bottom Line

Varenicline is a highly effective smoking-cessation medicine when paired with counselling/support, but renal dosing, neuropsychiatric monitoring, seizure history, nausea, sleep disturbance, and PBS course rules need active review.

Formulation & Access

Brand Names

Champix

Oral Routes

Tablets (0.5 mg, 1 mg). Take strictly after food with a full glass of water to prevent severe nausea.

Prescribing & PBS

S4. Authority Required (STREAMLINED PBS) varenicline tablet items are listed for smoking cessation; check current PBS restrictions, course limits, counselling/support requirements, and spacing from bupropion or repeat varenicline courses.

Indications & Use

Primary

PBSTGA

Smoking cessation in adults.

Clinical Place

First-line option for adults ready to stop smoking when renal function, neuropsychiatric history, seizure risk, pregnancy/lactation, and tolerability are acceptable. Pair with behavioural support; do not combine with NRT routinely without review.

Quick reference

Class & Role

Nicotinic Partial Agonist — Highly selective partial agonist at the alpha-4-beta-2 nicotinic receptor.

Route / Formulation

Tablets (0.5 mg, 1 mg). Take strictly after food with a full glass of water to prevent severe nausea. (Champix)

Usual Dose & Max

Days 1-3: PO 0.5 mg daily. Days 4-7: 0.5 mg twice daily. Day 8 onward: 1 mg twice daily for 12 weeks. Take after food with water. Max 2 mg/day; reduce dose in severe renal impairment.

Key Indication Doses

Set a target quit date and usually start varenicline 1-2 weeks before it. If abrupt quitting is not suitable, use a flexible quit date or gradual reduction plan supported by the PI rather than telling the patient they must continue smoking.

Best Uses

Varenicline is the most effective single-agent pharmacotherapy for smoking cessation, but causes vivid dreams and nausea and was previously (though no longer) flagged for neuropsychiatric risk.

Avoid / Cautions

Contraindicated in hypersensitivity. Use caution with severe renal impairment, end-stage renal disease, seizure history, significant neuropsychiatric symptoms, pregnancy, and lactation; monitor mood and behaviour during treatment.

Key Risks

Gastrointestinal: Nausea (up to 30% of patients. Often the main reason for quitting the drug). Neurological: Extremely vivid, bizarre, or terrifying dreams. Insomnia, headache. Psychiatric: Depression, agitation, suicidal ideation (Risk exists, but largely attributed to the psychological trauma of nicotine withdrawal rather than the drug itself).

Key Interactions

Minimal CYP450 interaction burden. Combining with transdermal nicotine replacement can increase adverse effects such as nausea, headache, vomiting, dizziness, dyspepsia, and fatigue; use combination only with clear review.

Monitoring

Check renal function before dose selection. Monitor mood, behaviour change, agitation, depressed mood, suicidal ideation, seizures, nausea, sleep disturbance, and smoking-cessation progress.

Clinical Pearl

Taking the tablet on an empty stomach guarantees severe nausea. Taking it immediately after a large meal with a full 250mL glass of water drastically reduces this.

Access

PBS streamlinedChampix0.5 mg tablet

Brand: Champix
PBS status: PBS streamlined
Formulation: Tablets (0