Chantix

Aka: Chantix, Varenicline

1. Indications
   1. Tobacco Cessation
   2. Not considered first-line therapy in teens who use Tobacco
2. Precautions
   1. FDA Pregnancy Category C
   2. Increased cardiovascular events in Tobacco users with history of cardiovascular disease
      1. http://www.fda.gov/Drugs/DrugSafety/ucm259161.htm
   3. Avoid combination with other Tobacco Cessation medications
      1. No do not use with Nicotine Replacement
      2. Safety in combination with Bupropion is unknown
   4. FDA black box warning
      1. Serious neuropsychiatric symptoms
      2. May cause depressed mood and Suicidality
      3. May cause behavior change including hostility, agitation
3. Mechanism
   1. Nicotine binds nicotinic acetylcholine receptor a4b2
      1. Binding stimulates CNS mesolimbic Dopamine system
      2. Reinforces nicotine exposure
   2. Chantix activity
      1. Chantix Blocks nicotine at a4b2 receptors
      2. Chantix selectively binds a4b2 receptors
4. Dosing
   1. Start: 0.5 mg once daily on days 1 to 3
   2. Next: 0.5 mg twice daily on days 4 to 7
   3. Next: 1 mg twice daily
   4. Duration
      1. Continue for 12 weeks
      2. Additional 12 weeks may be used if successful
   5. Dosing adjustment: Renal Impairment
      1. Severe renal Impairment: Max dose 0.5 mg PO bid
      2. End-stage renal disease: Max dose 0.5 mg PO daily
5. Adverse Effects
   1. Nausea (30%)
   2. Headache (10%)
   3. Sleep disturbance (Insomnia, or abnormal dreams): 10%
   4. Constipation
   5. Flatulence
   6. Suicidal Ideation
      1. Reported in 1 per 10,000 patients taking Chantix
      2. Kuehn (2008) JAMA 299(10):1121-2
6. Cost
   1. Monthly: $120
7. Efficacy
   1. Cessation for >1 year in 20% (10% with Placebo)
   2. Cessation rates are as good if not better than Zyban
   3. Number Needed to Treat (for longterm cessation): 9
8. References
   1. Larzelere (2012) Am Fam Physician 85(6): 591-8
   2. Love (2007) Am Fam Physician 76:279-80
   3. Oncken (2006) Arch Intern Med 166: 1571-7
   4. Tonstad (2006) JAMA 296: 64-71