What are the contraindications for Varenicline (Chantix)?

Contraindications for Varenicline (Chantix)

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

Primary Contraindications

• Hypersensitivity: Patients with known history of serious hypersensitivity reactions to varenicline 1
• Brain metastases: Contraindicated due to increased seizure risk 2, 3

Special Populations Requiring Caution

While not absolute contraindications, special consideration is needed for:

Renal Impairment

• Severe renal impairment (creatinine clearance <30 mL/min): Dose reduction required (0.5 mg once daily initially, maximum 0.5 mg twice daily) 1
• End-stage renal disease with hemodialysis: Maximum dose 0.5 mg once daily 1

Psychiatric Considerations

• History of psychiatric illness: Not an absolute contraindication, but requires close monitoring for neuropsychiatric symptoms 3, 4
• Monitor for: Depression, agitation, changes in behavior, suicidal ideation 1

Neuropsychiatric Safety Considerations

Although not contraindications, clinicians should be aware of potential neuropsychiatric effects:

• FDA requires warnings about potential mood changes, agitation, depression, suicidal ideation 3
• Recent large studies (EAGLES trial) found no significant increase in serious neuropsychiatric events compared to nicotine patch or placebo 3
• Patients should be advised to stop varenicline and contact healthcare provider immediately if they experience:
  • Agitation
  • Depressed mood
  • Unusual changes in behavior or thinking
  • Suicidal ideation or behavior 1

Common Side Effects to Consider

While not contraindications, these common side effects may affect treatment decisions:

• Nausea: Most common side effect (28-29% of patients) 3
• Insomnia: Occurs in approximately 14% of patients 3
• Abnormal dreams: Reported in 10-13% of patients 3

Clinical Implications

When prescribing varenicline:

1. Screen for history of hypersensitivity to the medication
2. Assess for presence of brain metastases
3. Evaluate renal function and adjust dosing accordingly
4. Consider psychiatric history and implement appropriate monitoring
5. Educate patients about potential side effects and when to seek medical attention

Despite these considerations, varenicline remains a first-line therapy for smoking cessation due to its superior efficacy compared to other options, with an odds ratio of 2.88 times compared to placebo 3.