Table 4.

Dosage guidelines, safety aspects and other clinical considerations for Varenicline and Bupropion

	Varenicline	Bupropion
Formats	1st week of treatment: 0.5 mg tablet Rest of treatment period: 1 mg tablet Follow-up: 1 mg 150 mg extended-release tablets	150 mg sustained release tablets
Dosage	Days 1–3: 0.5 mg /24 h Days 4–7: 0.5 mg /12 h Stop smoking between days 7 and 10 Day 8–12 weeks: 1 mg/12 h Start: 1 week before stopping Take with water after eating Dose adjustment in patients with renal insufficiency Duration: 12 weeks, with possible extension of 12 weeks Possible start 1 month before D-day with a weekly reduction regimen	Days 1-6: 150 mg/24 h Day 7 and following: 150 mg twice a day with at least 8 hours between doses and not close to bedtime Stop smoking during the 2nd week of treatment Duration:7-9 weeks
Precautions	Adjust dose for kidney failure (clearance < 30 mL/min consider half the dose) Contraindicated in end-stage renal failure, pregnancy and lactation	Drugs that lower the proconvulsive threshold Liver disease Adolescents Pregnancy and lactation
Contraindications		History of seizures Eating disorders Sudden interruption of alcohol or benzodiazepine consumption (risk of seizure) Use of MAOIs in the previous 2 weeks.
Side effects (most common)	Nausea, headache, insomnia, nasopharyngitis, gastrointestinal disorders	Nausea, headache, insomnia, dry mouth, anxiety, gastrointestinal disorder s and seizures
Advantages	Most effective drug in monotherapy Two daily doses and good adherence Different mechanism of action in second treatments Absence of hepatic metabolism. Lower risk of interactions	Good adherence Less weight gain Useful in patients with depression Possible combination with NRT
Disadvantages		Seizure risk