Chantix (Varenicline) for Smoking Cessation
Chantix (varenicline) is the most effective single pharmacotherapy for smoking cessation and should be prescribed at a target dose of 1 mg twice daily for 12 weeks, combined with behavioral counseling, for all motivated smokers without contraindications. 1, 2
Treatment Regimen
Standard Dosing Protocol
- Begin varenicline 1-2 weeks before the quit date using the following titration schedule to minimize nausea 3, 2:
- Days 1-3: 0.5 mg once daily
- Days 4-7: 0.5 mg twice daily
- Week 2 through week 12: 1 mg twice daily (target dose)
- Take tablets after eating with a full glass of water 2
Treatment Duration
- Standard course: 12 weeks minimum 3, 1, 2
- For patients who successfully quit during the initial 12 weeks, prescribe an additional 12-week course (total 24 weeks) to significantly increase long-term abstinence rates 3, 1, 2
- Therapy may be extended to 6-12 months to promote continued cessation, though avoiding longer periods when possible 3
Behavioral Counseling Integration
Varenicline must always be combined with behavioral counseling for optimal outcomes 1. The combination of counseling with medication is superior to either approach alone 3.
Counseling Framework (5 A's Strategy)
- Ask about tobacco use at every visit 3
- Advise the smoker to quit in a clear, strong, personalized manner 3
- Assess willingness to make a quit attempt 3
- Assist with counseling and pharmacotherapy 3
- Arrange follow-up to support the patient 3
Counseling Intensity
- Minimum: Brief 3-minute counseling focusing on motivation and previous quit attempts 3
- Recommended: 4 or more sessions of 10-30+ minutes during the 12-week course, with longer and more frequent sessions linked to higher success rates 1
- Sessions should include practical problem-solving (removing tobacco products from home/work, planning for high-risk situations) and coping skills development 3
Follow-Up Schedule
- First follow-up: Within 2-3 weeks after starting pharmacotherapy to assess smoking status and medication side effects 3, 1
- Additional follow-up: At 12 weeks and at end of therapy if extended beyond 12 weeks 1
- Minimum follow-up intervals: Every 12 weeks during therapy 3
Efficacy
Varenicline increases quit odds almost 3-fold compared to placebo (RR 2.24,95% CI 2.06-2.43) 1. It demonstrates superior efficacy compared to:
- Bupropion (RR 1.39,95% CI 1.25-1.54) 1
- Single forms of nicotine replacement therapy (RR 1.25,95% CI 1.14-1.37) 1
In clinical trials, continuous abstinence rates during weeks 9-12 were 43.9% with varenicline versus 29.8% with bupropion and 17.6% with placebo 1. At 52 weeks, abstinence rates were 23% with varenicline versus 14.6% with bupropion and 10.3% with placebo 1.
Side Effects and Management
Common Side Effects
- Nausea: 28-40% of patients, typically mild to moderate, peaks in weeks 1-2, and diminishes over time 3, 1
- Insomnia: 14% of patients 1
- Abnormal dreams: 10-13% of patients 1
Dose Adjustment Strategies
- Consider flexible dosing (0.5 mg/day to 1 mg twice daily) allowing patients to self-regulate based on tolerability, which may reduce adverse effects while maintaining efficacy 1
- Temporary or permanent dose reduction is appropriate for patients who cannot tolerate adverse effects 2
Monitoring and Safety
Neuropsychiatric Monitoring
Monitor for neuropsychiatric symptoms including depression, agitation, behavioral changes, and suicidal ideation throughout treatment 3, 1. However, the large EAGLES trial found no significant increase in neuropsychiatric events with varenicline compared to nicotine patch or placebo 1. These symptoms may be associated with nicotine withdrawal rather than varenicline itself, though events have been observed in individuals who continued smoking while on varenicline 4.
Contraindications and Precautions
- Contraindicated in patients with history of serious hypersensitivity or skin reactions to varenicline 2
- Avoid in patients with brain metastases or history of seizures due to rare but significant seizure risk 1
- No dosage adjustment needed for mild to moderate renal impairment 2
- For severe renal impairment (CrCl <30 mL/min): Start at 0.5 mg once daily, titrate to maximum 0.5 mg twice daily 2
- For end-stage renal disease on hemodialysis: Maximum 0.5 mg once daily if tolerated 2
Management of Treatment Failure
If Patient Fails to Quit or Relapses
- Continue or resume initial pharmacotherapy, or switch to combination NRT before trying other options 3
- Identify and address factors contributing to the failed attempt 2
- Patients can be re-treated with varenicline once contributing factors are addressed; varenicline remains effective and well-tolerated for re-treatment 1
- Progressively intensify behavioral therapy with referral to specialty care (psychiatrist, psychologist) as indicated 3
Alternative Approach for Patients Unable to Quit Abruptly
For patients not able or willing to quit abruptly, consider a gradual approach 2:
- Begin varenicline and reduce smoking by 50% from baseline within first 4 weeks
- Reduce by additional 50% in next 4 weeks
- Continue reducing with goal of complete abstinence by 12 weeks
- Continue treatment for additional 12 weeks (total 24 weeks)
- Encourage patients to quit sooner if they feel ready 2
Key Clinical Pearls
- Nicotine withdrawal symptoms typically peak within 1-2 weeks of quitting and then subside; encourage continued therapy through brief slips 3
- Patients who don't quit immediately may quit later after withdrawal symptoms subside 3
- Track attempts at smoking reduction; if reduction stalls or total abstinence seems unlikely, switch to different pharmacotherapy 3
- Varenicline has a favorable risk/benefit ratio with no significant link to increased cardiovascular adverse events 1
- The substantial benefits of immediate smoking cessation should be weighed against the individual's risk of adverse events 3