How should I prescribe varenicline (Chantix) for a motivated adult smoker who wants to quit and has no absolute contraindications?

How to Prescribe Varenicline (Chantix) for Smoking Cessation

Prescribe varenicline 1 mg twice daily for 12 weeks combined with mandatory behavioral counseling—this is the single most effective pharmacotherapy for smoking cessation, nearly tripling quit rates compared to placebo. 1, 2

Standard Dosing Regimen

Begin varenicline 1–2 weeks before the patient's chosen quit date using the FDA-approved titration schedule to minimize nausea: 1, 3

• 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 each dose after eating with a full glass of water. 3

Treatment Duration

• Standard course: 12 weeks for all patients 1, 2, 3
• Extended therapy: 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—approximately 70% versus 50% with placebo at 24 weeks. 1, 2

Mandatory Behavioral Counseling Integration

Varenicline must always be combined with behavioral counseling—pharmacotherapy alone significantly reduces efficacy. 1, 2, 4

Minimum Counseling Requirements:

• At least 4 counseling sessions during the 12-week treatment period 1, 2, 4
• First session within 2–3 weeks of starting medication 1
• Session duration: 10–30+ minutes each; longer sessions are linked to higher quit rates 1, 2

Counseling Content Must Include:

• Skills training for recognizing high-risk situations 2, 4
• Social support strategies 2, 4
• Motivational interviewing techniques 2, 4
• Practical problem-solving for triggers and coping strategies 2, 4

Use the 5 A's Framework:

• Ask about tobacco use at every visit 5, 2
• Advise to quit with a clear, strong, personalized message 5, 2
• Assess willingness to make a quit attempt 5
• Assist with counseling and pharmacotherapy 5
• Arrange follow-up to support the patient 5

Follow-Up Schedule

Arrange structured follow-up visits at these mandatory intervals: 1, 2, 4

1. First visit: 2–3 weeks after starting medication (assess smoking status, medication side effects, and risk of relapse) 1, 2
2. Second visit: 12 weeks (end of initial course) 1, 2
3. Ongoing: Minimum every 12 weeks if therapy is extended 1, 2

Common Side Effects and Management

Nausea (occurs in 28–40% of patients):

• Typically peaks in weeks 1–2 and diminishes over time 1, 6
• Reassure patients that nausea usually improves after the first 2 weeks 1
• If intolerable: Consider flexible dosing (0.5 mg once daily up to 1 mg twice daily), allowing patients to self-adjust based on tolerability 1
• The titration schedule is specifically designed to minimize this dose-dependent effect 1

Other Common Side Effects:

• Insomnia (14%) 1
• Abnormal dreams (10–13%) 1

Neuropsychiatric Safety Monitoring

Monitor for neuropsychiatric symptoms including depression, agitation, behavioral changes, and suicidal ideation throughout treatment. 1, 4

Critical reassurance from high-quality evidence: The large EAGLES trial (>8,000 participants) found no significant increase in neuropsychiatric adverse events with varenicline compared to nicotine patch or placebo, in both patients with and without psychiatric disorders. 1

Immediate discontinuation is advised if any of the following emerge: 1

• Worsening depression
• Suicidal ideation or behavior
• Agitation, anxiety, or panic attacks
• Hostility or aggression

Absolute Contraindications

• History of brain metastases (due to seizure risk) 1
• Active seizure disorder 1
• History of serious hypersensitivity or skin reactions to varenicline 1
• Pregnancy and breastfeeding (not FDA-approved for these populations) 1

Special Populations

Severe Renal Impairment (CrCl <30 mL/min):

• Start at 0.5 mg once daily 3
• Titrate to 0.5 mg twice daily if tolerated (maximum dose) 3

End-Stage Renal Disease on Hemodialysis:

• Maximum dose 0.5 mg once daily if tolerated 3

Patients with Psychiatric History:

• Varenicline can be safely used long-term (up to 24 weeks) 1
• Take a psychiatric history and suicide risk assessment before prescribing 1
• Current evidence does not support withholding varenicline based solely on psychiatric history 1

Oncology Patients Receiving Chemotherapy:

• Varenicline-related nausea may require especially careful management 1

Management of Treatment Failure or Relapse

If the patient fails to quit or relapses after the first attempt: 2, 4

1. Identify and address factors that contributed to failure (inadequate behavioral support, living/working with smokers, stress, depression, substance use) 1
2. Continue or resume varenicline with intensified behavioral therapy 1, 2
3. Alternative options:
   • Switch to combination NRT (patch + short-acting form) 2, 4
   • Try combination pharmacotherapy (combination NRT + bupropion) 2, 4
   • Extend treatment duration 2

Varenicline remains effective and well-tolerated for re-treatment in patients who previously failed therapy once contributing factors are addressed. 1

Comparative Efficacy

Varenicline is superior to all other single medications for smoking cessation: 1, 2

• Varenicline vs. placebo: RR 2.24 (95% CI 2.06–2.43)—nearly triples quit odds 1, 2
• Varenicline vs. bupropion: RR 1.39 (95% CI 1.25–1.54) 1
• Varenicline vs. single NRT: RR 1.25 (95% CI 1.14–1.37) 1
• Quit rates at 6 months: 21.8–28% with varenicline versus 9.4% with placebo 2

Common Pitfalls to Avoid

• Never prescribe varenicline without behavioral counseling—this significantly reduces efficacy 2, 4
• Do not provide inadequate counseling duration (<10 minutes or <4 sessions) 1, 2
• Do not discontinue therapy prematurely before completing 12 weeks 4
• Do not forget to extend therapy to 24 weeks in successful quitters to maximize long-term abstinence 1, 2
• Do not delay treatment initiation—begin 1–2 weeks before the quit date 1, 3