From the Guidelines
The American Gastroenterological Association recommends adding pharmacological agents to lifestyle interventions for adults with obesity or overweight with weight-related complications who have had an inadequate response to lifestyle interventions alone. When considering pharmacological interventions, the AGA suggests using semaglutide 2.4 mg with lifestyle modifications, compared with lifestyle modifications alone, due to its glucoregulatory benefits and approval for the treatment of type 2 diabetes 1. The selection of medication should be based on the clinical profile and needs of the patient, including comorbidities, patient preferences, costs, and access to therapy. Some key points to consider when selecting a medication include:
- Semaglutide 2.4 mg may be prioritized over other approved anti-obesity medications (AOMs) for the long-term treatment of obesity for most patients, but it may cause gastrointestinal side effects such as nausea and vomiting 1.
- Liraglutide 3.0 mg and phentermine-topiramate ER are also suggested as options, but with specific implementation considerations, such as avoiding phentermine-topiramate ER in patients with a history of cardiovascular disease and uncontrolled hypertension 1.
- Naltrexone-bupropion ER may be considered for patients who are attempting smoking cessation or have depression, but it should be avoided in patients with seizure disorders and used with caution in patients at risk of seizures 1. It is essential to individualize treatment approaches based on the person's medical history, life circumstances, preferences, and motivation, and to consider combining treatment approaches if appropriate 1. Regular monitoring for side effects is crucial, and treatment should be continued only if a significant weight loss is achieved within 3-6 months. Medication selection should always be used as an adjunct to ongoing lifestyle modifications, including reduced caloric intake and increased physical activity.
From the FDA Drug Label
Patients must be informed that Phentermine Hydrochloride is a short-term (a few weeks) adjunct in a regimen of weight reduction based on exercise, behavioral modification and caloric restriction in the management of exogenous obesity, and that co-administration of Phentermine with other drugs for weight loss is not recommended [ see Indications and Usage ( 1) and Warnings and Precautions ( 5) ].
The clinical guidelines for the drug treatment of obesity or weight loss with Phentermine include:
- Using Phentermine as a short-term adjunct in a regimen of weight reduction
- Combining Phentermine with exercise, behavioral modification, and caloric restriction in the management of exogenous obesity
- Not recommending co-administration of Phentermine with other drugs for weight loss 2
From the Research
Clinical Guidelines for Drug Treatment of Obesity or Weight Loss
The clinical guidelines for the drug treatment of obesity or weight loss involve the use of antiobesity medications (AOMs) in combination with lifestyle interventions. These medications can be classified according to their mechanisms of action, including:
- Orlistat, which modifies digestive tract absorption and is associated with gastrointestinal adverse effects such as oily fecal spotting and urgency 3, 4
- Centrally acting drugs, such as phentermine-topiramate and naltrexone-bupropion, which regulate appetite in the brain and are associated with constipation and other adverse effects 3, 5
- Nutrient-stimulated hormone-based medications, such as liraglutide, semaglutide, and tirzepatide, which mimic the actions of enteropancreatic hormones and provide multiple cardiometabolic weight-loss benefits 3, 6
Efficacy of Antiobesity Medications
The efficacy of antiobesity medications has been studied in meta-analyses, with results showing that:
- Orlistat is associated with 3.1% greater weight loss compared to placebo 3
- Phentermine-topiramate is associated with 8.0% greater weight loss compared to placebo 3
- Naltrexone-bupropion is associated with 4.1% greater weight loss compared to placebo 3
- Liraglutide is associated with 4.7% greater weight loss compared to placebo 3
- Semaglutide is associated with 11.4% greater weight loss compared to placebo 3, 6
- Tirzepatide is associated with 12.4% greater weight loss compared to placebo 3
FDA-Approved Pharmacotherapy for Weight Loss
The FDA has approved several medications for the treatment of obesity, including: