Dosing Regimen for Champix (Varenicline)
The recommended dosing for Champix (varenicline) is to start with 0.5 mg once daily for days 1-3, increase to 0.5 mg twice daily for days 4-7, then 1 mg twice daily from day 8 until the end of treatment (typically 12 weeks). 1
Initial Titration Schedule
Champix requires a one-week titration period to minimize side effects, particularly nausea:
- Days 1-3: 0.5 mg once daily
- Days 4-7: 0.5 mg twice daily
- Day 8 to end of treatment: 1 mg twice daily
Standard Treatment Duration
- The standard treatment course is 12 weeks (3 months)
- For patients who successfully quit smoking after 12 weeks, an additional 12-week course is recommended to further increase the likelihood of long-term abstinence 1
Administration Guidelines
- Take Champix after eating and with a full glass of water to minimize gastrointestinal side effects 1
- The patient should set a quit date, with Champix treatment beginning one week before this date
- Alternatively, the patient can begin Champix and then quit smoking between days 8 and 35 of treatment 1
Special Populations
Renal Impairment
- Mild to moderate renal impairment: No dosage adjustment needed
- Severe renal impairment (creatinine clearance <30 mL/min): Maximum 0.5 mg twice daily
- End-stage renal disease requiring hemodialysis: Maximum 0.5 mg once daily 1, 2
Elderly Patients
- No specific dosage adjustment required based on age alone
- Monitor renal function as elderly patients are more likely to have decreased renal function 1
Hepatic Impairment
- No dosage adjustment necessary for patients with hepatic impairment 1
Gradual Approach Option
For patients unable or unwilling to quit abruptly, a gradual approach can be considered:
- Begin standard dosing
- Reduce smoking by 50% within first 4 weeks
- Reduce by another 50% in next 4 weeks
- Aim for complete abstinence by 12 weeks
- Continue treatment for additional 12 weeks (24 weeks total) 1
Common Side Effects and Management
The most common adverse effect is nausea (reported in 16.3-41.9% of patients), which typically diminishes over time 3. Other common side effects include:
- Insomnia (14.2%)
- Headache (14.2%)
- Abnormal dreams
Important Considerations
- Neuropsychiatric adverse events have been reported with varenicline use
- Patients should be monitored for changes in mood, behavior, or thinking
- Caution is advised when operating vehicles or heavy machinery
- Patients should stop taking varenicline and contact healthcare provider immediately if they experience agitation, depressed mood, or suicidal ideation 1
Champix has demonstrated superior efficacy compared to other smoking cessation aids, with continuous abstinence rates significantly higher than placebo, bupropion SR, and nicotine replacement therapy 3, 4.