Class: Smoking Cessation Agent
Dosage Forms. Tablet: 0.5 mg, 1 mg
Common FDA Label Indication, Dosing, and Titration.
1. Smoking cessation: Initial dose, 0.5 mg po daily × 3 d, then 0.5 mg po bid × 4 d, then 1 mg po bid for the following 11 wk; may repeat additional 12-wk treatment if patient has not stopped smoking, and if patient has stopped, may increase likelihood of long-term abstinence
Off-Label Uses. None
MOA. Varenicline binds with high affinity and selectivity at α4β2 neuronal nicotinic acetylcholine receptors. Its efficacy in smoking cessation is believed to be the result of activity at α4β2 subtype of the nicotinic receptor where its binding produces agonist activity, while simultaneously preventing nicotine binding to these receptors.
Drug Characteristics: Varenicline
Medication Safety Issues: Varenicline
Drug Interactions: Varenicline. None known.
Adverse Reactions: Varenicline
Efficacy Monitoring Parameters. Abstinence from smoking tobacco.
Toxicity Monitoring Parameters. Seek medical attention if patient experiences severe abnormal behavior or suicidal thoughts.
Key Patient Counseling Points. Take drug after eating and with a full glass (8 ounces) of water. If agitation, depressed mood, changes in behavior or thinking, or suicidal ideation, stop taking and contact healthcare provider.
Clinical Pearls. Serious neuropsychiatric symptoms have been reported in patients being treated with varenicline. It may occur in patients without a history of psychiatric illness, although patients with bipolar disorder, depression, schizophrenia, or suicidal ideation appear to be at increased risk. Patients who continue to smoke are also at increased risk. FAA has banned its use in pilots and air traffic controllers. Patients and healthcare providers should weigh the risks of taking varenicline against the benefits of smoking cessation. In a recent meta-analysis, there was an increased, but not statistically significant, incidence of major adverse cardiovascular events (a combined outcome of cardiovascular-related death, nonfatal myocardial infarction, and nonfatal stroke) in patients using varenicline when compared to placebo. Dispense with FDA-approved medication guide.