What is the recommended dosing regimen for Champix (varenicline) in an adult smoker aged 18 and over with no significant past medical history?

Champix (Varenicline) Dosing for Smoking Cessation

Standard Dosing Regimen

The recommended dosing regimen for Champix (varenicline) in an adult smoker is a titrated schedule starting 1-2 weeks before the quit date: 0.5 mg once daily for days 1-3,0.5 mg twice daily for days 4-7, then 1 mg twice daily for weeks 2-12. 1, 2

Detailed Dosing Schedule

• Days 1-3: 0.5 mg orally once daily 1, 2
• Days 4-7: 0.5 mg orally twice daily 1, 2
• Weeks 2-12: 1 mg orally twice daily (maintenance dose) 1, 2

The titration schedule is specifically designed to minimize dose-dependent nausea, which occurs in 28-40% of patients. 2 This gradual dose escalation is critical for tolerability while achieving therapeutic efficacy. 3, 4

Treatment Duration

The standard treatment duration is 12 weeks, with an additional 12-week course (total 24 weeks) recommended for patients who successfully quit during the initial period to significantly increase long-term abstinence rates. 1, 2

• The 12-week standard course achieves continuous abstinence rates of 43.9-65.4% during weeks 9-12. 2, 3
• For successful quitters, extending treatment to 24 weeks increases continuous abstinence rates to 70.5% versus 49.6% with placebo (OR 2.48,95% CI 1.95-3.16). 2, 3
• Therapy may be extended to 6-12 months to promote continued cessation, though avoiding longer periods when possible is preferred. 1, 2

Behavioral Counseling Integration

Varenicline must always be combined with behavioral counseling for optimal outcomes. 2

• A minimum of 4 counseling sessions during the 12-week course is recommended, with the first session within 2-3 weeks of starting treatment. 2
• Sessions should last 10-30+ minutes, with longer and more frequent sessions linked to higher success rates. 2
• Use structured frameworks such as the 5 A's strategy (Ask, Advise, Assess, Assess, Assist, Arrange). 2

Follow-Up Schedule

Follow-up should occur within 2-3 weeks after starting pharmacotherapy, with additional assessments at 12 weeks and at minimum 12-week intervals during therapy. 1, 2

• The first follow-up assesses smoking status, medication side effects, and tolerability. 2
• Monitor for risk of relapse and need for dose adjustments or therapy modifications. 2
• Continue follow-up after completion of therapy. 1

Common Side Effects and Management

Nausea is the most common side effect, occurring in 28-40% of patients, typically peaking in weeks 1-2 and diminishing over time. 2, 4

• Reassure patients that nausea typically improves after the first 2 weeks. 2
• The titration schedule specifically addresses this by gradually increasing the dose. 2
• Nausea may require careful management in cancer patients undergoing chemotherapy. 1, 2

Other common side effects include:

• Insomnia: 14% of patients 2
• Abnormal dreams: 10-13% of patients 2
• Headache: 14.2% of patients 4

Neuropsychiatric Monitoring

Monitor for neuropsychiatric symptoms including depression, agitation, behavioral changes, and suicidal ideation throughout treatment, though large-scale trials found no significant increase in neuropsychiatric events with varenicline compared to placebo. 1, 2

• A pooled analysis of 3,091 varenicline-treated patients versus 2,005 placebo patients showed no significant increase in overall psychiatric disorders (10.7% vs 9.7%, RR 1.02,95% CI 0.86-1.22). 5
• Discontinue use if serious neuropsychiatric symptoms develop. 1

Contraindications and Special Populations

Varenicline is contraindicated in patients with brain metastases due to seizure risk and in those with history of serious hypersensitivity or skin reactions to varenicline. 1, 2

• Avoid in patients with history of seizures or conditions that lower seizure threshold. 2
• Renal impairment: Dose reduction to 1 mg once daily is indicated for severe renal insufficiency. 6
• No dose adjustment required for mild to moderate renal impairment. 6
• No dose adjustment needed based on age, sex, or race after accounting for renal function. 6

Dose Escalation for Non-Responders

For patients who tolerate varenicline well but continue smoking after 8 weeks at standard dosing, increasing to 3 mg/day (1.5 mg twice daily) may be considered. 7

• This approach achieved 40% continuous abstinence rates in patients who continued smoking at 8 weeks. 7
• Adverse events occurred in 30% of patients receiving increased doses, mostly mild (nausea, vomiting, abnormal dreams, insomnia). 7
• Only 2.7% discontinued due to adverse events with the higher dose. 7

Management of Treatment Failure or Relapse

If patients fail to quit or relapse, continue or resume varenicline, or switch to combination nicotine replacement therapy before trying other options. 2

• Identify and address factors contributing to failure: inadequate behavioral support, elevated stress/anxiety, living with smokers, substance use. 2
• Progressively intensify behavioral therapy with referral to specialty care as indicated. 1, 2
• Patients who previously failed varenicline can be re-treated once contributing factors are addressed, using the same standard dosing regimen. 2

Efficacy Data

Varenicline is the most effective single pharmacotherapy for smoking cessation, increasing quit odds almost 3-fold compared to placebo (RR 2.24,95% CI 2.06-2.43). 2

• Superior to bupropion (RR 1.39,95% CI 1.25-1.54) and single forms of nicotine replacement therapy (RR 1.25,95% CI 1.14-1.37). 2
• At 52 weeks, abstinence rates were 21.9-34.6% with varenicline versus 10.3-14.6% with placebo or bupropion. 2, 3