α4β2 nicotinic partial agonist
Varenicline
Brand names: Champix
Adult dose
Dose: Day 1-3: 500 micrograms OD. Day 4-7: 500 micrograms BD. Day 8+: 1mg BD x12 weeks
Route: PO
Frequency: BD
Dose adjustments
Renal
Reduce if eGFR <30
Clinical pearls
- Smoking cessation — most effective single agent
- Set quit date 1-2 weeks after start; UK supply restored 2024 after recall
Contraindications
- Pregnancy/breastfeeding
- Severe renal impairment (relative)
- Hypersensitivity
Side effects
- Nausea
- Insomnia
- Abnormal dreams
- Mood changes
- Suicidal ideation (signal)
- Cardiovascular events (rare)
- Seizures
Interactions
- Smoking cessation alters CYP1A2 substrates (theophylline, clozapine)
Monitoring
- Mood
- Smoking status
Reference: BNF; NICE NG209; MHRA; https://bnf.nice.org.uk/drugs/varenicline/. Verify against your local formulary and the latest BNF before prescribing.
Related
Curated clinical cross-links plus same-class fallbacks.
Calculators
Pathways
- Acute Behavioural Disturbance / Rapid Tranquillisation · RCEM 2022; RCPsych 2022; NICE NG10
- Self-Harm Presentation · NICE NG225 (2022)
- Capacity Assessment (Mental Capacity Act) · MCA 2005; Code of Practice
- Acute Psychosis Management · NICE CG178 2014
- Depression Management · NICE CG90 2022
- Lithium Therapy Monitoring · NICE CG185 / BNF