Table. Drugs used in the maintenance of weight loss.

Drug	Doses available	Mode of action	Adverse effects	Contraindications	Efficacy (placebo subtracted losses)	Cost*
Phentermine	15, 30, 40 mg once daily	Sympathomimetic amine	Dry mouth Difficulty with sleeping Increased heart rate and blood pressure	Coronary artery disease Cardiac arrhythmias Use of antidepressant drug	6.4% weight loss	$145/month at highest dose
Orlistat	120 mg three times a day with meals	Intestinal lipase inhibitor	Steatorrhea	Pregnancy or breast feeding	4.1% weight loss	$92/month over-the-counter
Liraglutide 3 mg	0.6–3 mg once daily injection	Slows gastric emptying Suppresses hunger	Nausea Diarrhoea Constipation	History of pancreatitis	7.0% weight loss	$387/month at highest dose
Semaglutide	0.25–1 mg weekly injection	Slows gastric emptying Suppresses hunger	Nausea Diarrhoea Constipation	History of pancreatitis	8.6% weight loss	$132/month for 1 mg for patients without diabetes
Bupropion 90 mg/ naltrexone 8 mg	1–4 tablets daily	Increases melanocortin system activity	Nausea Constipation	Use of opioid analgesia Use of phentermine	6.3% weight loss	$242/month at highest dose
Topiramate	25–100 mg daily	Unknown	Paraesthesia Confusion Fetal abnormalities (cleft lip)	Glaucoma History of renal stones Pregnancy	7% weight loss	$22/month

* Costs in 2021