Varenicline Tartrate

Indications

Varenicline Tartrate is used for: Smoking cessation aid

Adult Dose

Smoking Cessation Set a date to stop smoking and begin varenicline 1 week before this date Alternatively, the patient can begin varenicline and then quit smoking between days 8 and 35 of treatment Also see Administration Quit smoking date regimen Initiate regimen 1 week before quit smoking date Days 1-3: 0.5 mg PO qDay Days 4-7: 0.5 mg PO BID Day 8 to end of treatment: 1 mg PO BID If quitting is successful after 12 weeks, continue another 12 weeks at 1 mg q12hr Gradual approach to quitting For patients who are sure that they are not able or willing to quit abruptly, consider a gradual approach to quitting smoking with varenicline Begin dosing and reduce smoking by 50% from baseline within the first 4 weeks, by an additional 50% in the next 4 weeks, and continue reducing with the goal of reaching complete abstinence by 12 weeks Continue varenicline for an additional 12 weeks, for a total of 24 weeks of treatment Encourage patients to attempt quitting sooner if they feel ready

Child Dose

<18 years: Safety and efficacy not established

Renal Dose

Renal impairment Mild-to-moderate (CrCl ?30 mL/min): No dosage adjustment required Severe (CrCl <30 mL/min): 0.5 mg PO qDay initially; may increase to 0.5 mg PO q12hr ESRD on hemodialysis: Not to exceed 0.5 mg PO qDay

Administration

Taken after eating with full glass of water

Contra Indications

Documented hypersensitivity or skin reactions to drug or components of formulation. Nonsmokers.

Precautions

Monitor for signs of suicidal ideation or behaviour, or changes in behaviour. May affect performance of skilled tasks. Not recommended for use in children <18 yr. Pregnancy, lactation.

Pregnancy-Lactation

Pregnancy Available data have not suggested increased risk for major birth defects following exposure to varenicline in pregnancy, compared with women who smoke; smoking during pregnancy causes increased risks of orofacial clefts, premature rupture of membranes, placenta previa, placental abruption, ectopic pregnancy, fetal growth restriction and low birth weight, stillbirth, preterm delivery and shortened gestation, neonatal death, sudden infant death syndrome and reduction of lung function in infants; it is not known whether quitting smoking with varenicline during pregnancy reduces these risks Lactation Because there are no data on presence of varenicline in human milk and effects on breastfed infant, breastfeeding women should monitor their infant for seizures and excessive vomiting, which are adverse reactions that have occurred in adults that may be clinically relevant in breastfeeding infants

Interactions

Increased incidence of adverse effects (nausea, vomiting) w/ transdermal nicotine. Increased exposure w/ cimetidine.

Side Effects

Side effects of Varenicline Tartrate : N>10% Nausea (15-40%; dose related), Abnormal dreams, Headache, Insomnia 1-10% Appetite changes, Chest pain, Constipation, Dry mouth, Dyspepsia, Dyspnea, Flatulence, Gastroesophageal reflux disease (GERD), Fatigue or lethargy, Pruritus, Rash, Somnolence, Rhinorrhea, Vomiting, Upper respiratory tract disorder Frequency Not Defined (selected) Abnormal liver function tests, Anemia, Anxiety, Arrhythmia, Arthralgia, Depression, Diarrhea, Dizziness, Epistaxis, Hypertension, Myocardial infarction (MI), Polyuria, Respiratory disorder

Mode of Action

Varenicline Tartrate is a partial neuronal alpha 2 beta 2 nicotinic acetylcholine receptor agonist. It works as a smoking cessation aid by preventing nicotine stimulation of mesolimbic dopamine system. It also stimulates dopamine activity but to a much lesser extent than nicotine does, resulting in reduced craving and withdrawal symptoms.