varenicline
Brands: Chantix
Last reviewed 2025-12-30
Reviewed by PsychMed Editorial Team.
Quick answers
What is varenicline?
Varenicline (brand Chantix; generics) is a smoking-cessation medication that acts as a partial agonist at nicotinic acetylcholine receptors (α4β2). It can reduce cravings and blunt the reinforcing effects of nicotine (label/guideline).
What is Chantix?
Chantix is a brand name for varenicline.
What is Chantix (varenicline) used for?
Label indications include: Smoking cessation (label).
What drug class is Chantix (varenicline)?
Nicotinic acetylcholine receptor partial agonist (α4β2) used to support smoking cessation by reducing cravings and blunting nicotine reinforcement; often paired with behavioral support (label/guideline).
What strengths does Chantix (varenicline) come in?
Oral tablets in multiple strengths (label).
Snapshot
- Class: Adjunctive therapy
- Common US brands: Chantix
- Therapeutic drug monitoring not routinely recommended.
- Last reviewed: 2025-12-30
Clinical Highlights
Varenicline (brand Chantix; generics) is a smoking-cessation medication that acts as a partial agonist at nicotinic acetylcholine receptors (α4β2). It can reduce cravings and blunt the reinforcing effects of nicotine (label/guideline). Systematic reviews consistently show varenicline increases quit rates compared with placebo and is among the most effective single-agent pharmacotherapies for smoking cessation (review).
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- A major practical point in psychiatric care is that smoking cessation itself can change medication levels. Tobacco smoke induces CYP1A2, so stopping smoking can increase exposure to CYP1A2 substrates such as clozapine and olanzapine; clinicians often plan follow-up when quit attempts start (clinical).
- Neuropsychiatric safety has been a historical concern. A large trial in smokers with and without psychiatric disorders found no significant increase in moderate-to-severe neuropsychiatric adverse events with varenicline compared with placebo, nicotine patch, or bupropion, while varenicline remained effective for cessation (trial).
- The most common adverse effect is nausea. Sleep-related effects (vivid dreams, insomnia) can occur and may overlap with nicotine withdrawal or baseline anxiety/insomnia symptoms (label/clinical).
- The compare view, varenicline evidence feed, and varenicline print page support counseling when smoking cessation intersects with depression, anxiety, and medication-level monitoring.
Dosing & Formulations
Oral tablets in multiple strengths (label). Label dosing is typically started before the target quit date with a short titration to reduce nausea, then continued for a defined course (often 12 weeks) with behavioral support (label/guideline).
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- Dose adjustment is recommended in severe renal impairment because varenicline is primarily renally eliminated (label).
Monitoring & Risks
Nausea is common and can improve with dose titration, taking doses with food, or dose adjustments (label/clinical). Sleep disturbance and abnormal dreams can occur; clinicians often differentiate medication effects from nicotine withdrawal and baseline insomnia/anxiety (label/clinical).
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- Mood and suicidality monitoring is common in patients with active depression or unstable psychiatric symptoms during quit attempts, because nicotine withdrawal can transiently worsen mood even when medication is safe (clinical).
- Renal function matters for dosing; baseline kidney assessment is common when comorbidity is present (label/clinical).
Drug Interactions
Varenicline has few CYP-mediated interactions because it has minimal metabolism; interaction review often focuses on renal dosing and on concurrent neuropsychiatric medications (label/clinical). Smoking cessation can increase levels of CYP1A2 substrates (for example, clozapine and olanzapine) due to reduced tobacco-smoke induction; this interaction effect is driven by quitting rather than by varenicline itself (clinical).
Practice Notes
Guidelines generally recommend combining pharmacotherapy with behavioral support (counseling, quit-line support, structured follow-up) to improve quit rates (guideline). If nicotine withdrawal worsens anxiety or insomnia, clinicians often manage symptoms in parallel rather than discontinuing cessation therapy prematurely (clinical).
References
- Varenicline tablets prescribing information — DailyMed (2025)
- Nicotine receptor partial agonists for smoking cessation — Cochrane Database of Systematic Reviews (2016)
- Neuropsychiatric Safety AND Efficacy OF Varenicline, Bupropion, AND Nicotine Patch IN Smokers With AND Without Psychiatric Disorders (eagles): A Double Blind, Randomised, Placebo Controlled Clinical Trial — The Lancet (2016)
- Treating Tobacco Use and Dependence: 2008 Update — U.S. Department of Health and Human Services (2008)