varenicline at a glance
Medicine class
Partial agonist at neuronal nicotinic acetylcholine receptors
Licensed use
Smoking cessation in adults
Administration
Swallow the tablet whole with water, with or without food
Driving
Do not drive or use machinery if sleepy, dizzy or visually affected
What is varenicline used for?
The selected UK product is licensed for:
Helping adults stop smoking, alongside motivation, advice and behavioural support.
How does varenicline work?
Varenicline partly stimulates α4β2 nicotinic acetylcholine receptors, less strongly than nicotine. This can ease craving and withdrawal while blocking some of nicotine’s rewarding effect if tobacco is smoked.
varenicline preparations and strengths
Tablet
Route: Oral
Strengths: 0.5 mg, 1 mg
How to take varenicline
Take varenicline exactly as prescribed and follow the supplied instructions. A smoking quit plan and behavioural support can improve the likelihood of success.
Swallow tablets whole with water.
Tablets may be taken with or without food.
Ask the prescriber or pharmacist if adverse effects are difficult to tolerate rather than changing treatment yourself.
varenicline side effects
Common or expected effects
- Feeling sick
- Headache
- Difficulty sleeping or unusual dreams
- Dizziness, sleepiness or altered taste
- Indigestion, heartburn, vomiting, constipation or diarrhoea
- Sore or inflamed nose and throat
Get urgent medical advice
- Suicidal thoughts, severe mood or behavioural changes, psychosis or worsening mental illness
- Seizure
- Signs of heart attack or stroke
- Angioedema or anaphylaxis, including facial or throat swelling and breathing difficulty
- Severe rash, blistering or peeling skin
varenicline in pregnancy
Varenicline is not generally recommended during pregnancy because experience remains limited and alternatives have more safety information. If you become pregnant while taking it, contact your GP, midwife or prescriber promptly. Exposure alone does not usually require additional monitoring for major birth defects beyond routine antenatal care.
varenicline while breastfeeding
Varenicline is not usually recommended while breastfeeding because it is unknown how much reaches human milk or whether it affects the infant. A prescriber should discuss better-established smoking-cessation options while supporting efforts to remain smoke-free.
varenicline interactions
Varenicline has few direct pharmacokinetic interactions, but stopping smoking can alter the handling or effects of other treatments.
Theophylline, aminophylline, clozapine, olanzapine, erlotinib or riociguat
Stopping smoking can increase exposure to some medicines affected by tobacco smoke, so clinical review and monitoring may be needed.
Warfarin
Varenicline does not directly alter warfarin, but smoking cessation may change anticoagulant requirements; monitoring may be needed.
Common questions about varenicline
Answers are fully visible for fast scanning and source review.
What is varenicline used for?
Varenicline is licensed to help adults stop smoking. It is intended to be used with motivation, advice and behavioural support.
How does varenicline reduce nicotine cravings?
It partly activates the same brain receptors as nicotine, easing withdrawal, while preventing nicotine from activating them as strongly.
Can varenicline be taken with food?
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.