Table 1.

Anti-Obesity Medications. Shown are 10 takeaway messages regarding anti-obesity medications, including their mechanisms of action, approvals, illustrative side effects, and sentinel contraindications [7]. All anti-obesity medications are contraindicated in patients with hypersensitivity to the drug (e.g., anaphylaxis, angioedema), and should not be used in patients with overweight/pre-obesity or obesity who are pregnant or planning to become pregnant.

1.	Phentermine is an approved anti-obesity medication that is a sympathomimetic amine with possible adrenergic side effects. Phentermine is contraindicated in patients with cardiovascular disease and contraindicated in patients with uncontrolled hypertension.
2.	Phentermine hydrochloride (HCl) 8–37.5 mg is marketed in the United States (US) and is generally equivalent to 6.4–30 mg of phentermine resin marketed outside the US. Phentermine HCl tablets are commonly administered at 37.5 mg once per morning, or sometimes 18.75 mg twice a day. An alternative phentermine HCl formulation is administered 8 mg (or 4 mg if using one half 8 mg tablet) three times a day before meals. Finally, phentermine HCl is also supplied as capsules or disintegrating tablets, with doses of 15 and 30 mg once per morning or 15 mg twice a day.
3.	Although not consistent with the prescribing information indicated use, and while prohibited by some state laws, phentermine administration for longer than 12 weeks is supported by clinical data and opinion leaders.
4.	Semaglutide is a glucagon-like peptide-1 receptor agonist. Semaglutide 2.4 mg subcutaneously per week is an approved anti-obesity medication. Semaglutide at lower subcutaneous injectable doses 0.25–2.0 mg per week and at oral doses of 7–14 mg per day, is indicated to lower blood sugar in patients with type 2 diabetes mellitus. Potential side effects include gastrointestinal adverse events (e.g., nausea). Semaglutide is contraindicated in patients with personal or family history of medullary thyroid cancer or type 2 multiple endocrine neoplasia.
5.	Liraglutide is a glucagon-like peptide-1 receptor agonist approved at 3.0 mg subcutaneously per day for treatment of obesity and 1.8 mg subcutaneously per day for treatment of type 2 diabetes mellitus and to reduce the risk of major adverse cardiovascular events in adults with type 2 diabetes mellitus and established cardiovascular disease. Side effects include possible gastrointestinal adverse events (e.g., nausea). Liraglutide is contraindicated in patients with personal or family history of medullary thyroid cancer or type 2 multiple endocrine neoplasia.
6.	Phentermine/topiramate is an approved anti-obesity medication and is a combination of a sympathomimetic amine and anti-seizure/migraine medication with side effects that include paresthesias and dysgeusia; exposure to topiramate in the first trimester of pregnancy increases the risk of oral clefts (cleft lip with or without cleft palate).
7.	Naltrexone/bupropion is an approved anti-obesity medication and is a combination of an opioid antagonist and an antidepressant with possible gastrointestinal side effects. It is contraindicated in patients with uncontrolled hypertension, chronic opioid use, seizure disorders, and/or abrupt discontinuation of alcohol, benzodiazepines, barbiturates, or antiepileptic drugs.
8.	Orlistat is an approved anti-obesity medication and is a gastrointestinal lipase inhibitor with possible adverse experiences that include oily rectal discharge and flatus; it is contraindicated in patients with chronic malabsorption syndrome and cholestasis.
9.	Semaglutide, liraglutide, and phentermine/topiramate can be taken with or without meals. Orlistat should be taken three times a day with each meal that contains fat; bupropion/naltrexone should not be taken with high-fat meals due to increased gastrointestinal absorption.
10.	Biodegradable oral non-systemic superabsorbent hydrogel is an FDA-cleared weight loss aid that is made from cross-linked carboxymethylcellulose and citric acid that promotes fullness and may help to increase satiety to help with weight management. It is orally administered like a drug but regulated by the FDA as a class II medical device because it acts through mechanical modes of action.