varenicline: prescribing and clinical use
Focused clinical detail for use alongside current product information, local policy and patient-specific assessment.
varenicline: clinical details
Prescribing considerations
- Confirm motivation and arrange behavioural smoking-cessation support.
- Assess renal function, particularly in older adults or known renal disease; exposure rises as renal function declines.
- Review psychiatric history, seizure history, cardiovascular disease, pregnancy and breastfeeding status.
- Review medicines whose exposure or effect may change when smoking stops.
- Warn about possible dizziness, somnolence, visual effects, unusual dreams and altered alcohol response.
- Discuss possible irritability, depressed mood, insomnia or renewed craving after treatment ends.
Contraindications and cautions
- Hypersensitivity to varenicline or any product excipient.
Monitoring
- Smoking status, craving, withdrawal, adherence and tolerability.
- New or worsening depression, anxiety, aggression, suicidal thinking, psychosis or other behavioural change.
- Seizures and new or worsening cardiovascular symptoms.
- Renal function where impairment is present or suspected.
- Relevant clinical or laboratory measures for medicines affected by smoking cessation, such as INR or glucose.
Clinical pharmacology
Varenicline is a selective α4β2 neuronal nicotinic acetylcholine receptor partial agonist. It undergoes little metabolism, is predominantly excreted unchanged in urine and has an elimination half-life of approximately 24 hours. Clinically important CYP-mediated interactions are unlikely.
Formulation and product differences
- The selected product is an oral film-coated tablet containing varenicline as tartrate.
- Appearance, excipients and pack configuration can differ between authorised products; verify the product-specific SmPC when allergy or identification is relevant.
varenicline preparations and strengths
Tablet
Route: Oral
Strengths: 0.5 mg, 1 mg
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.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.