What are the medications for the management of obesity?

From the Guidelines

The most effective medication for the management of obesity is semaglutide (Wegovy), which can produce 15-20% weight loss over 68 weeks, and should be considered as the first-line treatment alongside lifestyle modifications. According to the American Gastroenterological Association (AGA) clinical practice guideline on pharmacological interventions for adults with obesity 1, semaglutide 2.4 mg with lifestyle modifications is suggested over lifestyle modifications alone, with a moderate quality of evidence. The guideline also 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, with a strong recommendation and moderate quality of evidence 1.

Medications for the management of obesity include several FDA-approved options, such as phentermine-topiramate (Qsymia), liraglutide (Saxenda), naltrexone-bupropion (Contrave), and orlistat (Xenical). These medications work by reducing appetite, increasing satiety, and slowing gastric emptying, or by blocking fat absorption in the intestines.

• Semaglutide is typically started at 0.25mg weekly, gradually increasing to 2.4mg weekly.
• Phentermine-topiramate combines a sympathomimetic with an anticonvulsant and can achieve 7-10% weight loss.
• Naltrexone-bupropion combines an opioid antagonist with an antidepressant for 5-8% weight loss.
• Orlistat works differently by blocking fat absorption in the intestines.
• Liraglutide 3.0 mg with lifestyle modifications is also suggested, with a conditional recommendation and moderate quality of evidence 1.

Medication selection should be personalized based on comorbidities, potential side effects, cost, and patient preference. These medications are generally indicated for patients with BMI ≥30 kg/m² or BMI ≥27 kg/m² with weight-related comorbidities, and should be continued long-term as obesity is a chronic disease requiring ongoing management. The AGA guideline provides implementation considerations for each medication, including potential side effects, contraindications, and monitoring requirements 1.

From the FDA Drug Label

Phentermine Hydrochloride, USP 15 mg and 30 mg is indicated as 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 for patients with an initial body mass index greater than or equal to 30 kg/m 2, or greater than or equal to 27 kg/m 2 in the presence of other risk factors (e.g., controlled hypertension, diabetes, hyperlipidemia).

Medications for the management of obesity include phentermine, which is indicated for short-term use as an adjunct to a weight reduction regimen.

• The indications for phentermine include exogenous obesity with a body mass index (BMI) of 30 kg/m^2 or higher, or 27 kg/m^2 or higher with other risk factors.
• Key points to consider when using phentermine for obesity management include:
  • Short-term use (a few weeks)
  • Adjunct to a regimen of exercise, behavioral modification, and caloric restriction
  • BMI criteria for initiation
  • Presence of other risk factors (e.g., controlled hypertension, diabetes, hyperlipidemia) 2

From the Research

Medications for Obesity Management

The following medications are approved by the US FDA for the treatment of obesity:

• Orlistat
• Lorcaserin
• Liraglutide
• Phentermine/topiramate
• Bupropion/naltrexone 3
• Phentermine 4
• Semaglutide 2.4 mg
• Tirzepatide 4
• Naltrexone SR/bupropion SR 4
• Liraglutide 3.0 mg 4

Efficacy of Anti-Obesity Medications

Studies have compared the efficacy of anti-obesity medications, including:

• Phentermine
• Phentermine/topiramate
• Liraglutide
• Naltrexone/bupropion
• Lorcaserin
• Orlistat 5 The results show that all these medications are effective in inducing and maintaining weight loss, with phentermine being associated with a significantly higher prevalence of ≥5% weight loss than the other medications, except for liraglutide 5.

Pharmacological Treatment for Obesity

Pharmacological therapies approved by the Australian Therapeutic Goods Administration and the US Food and Drug Administration for the management of obesity in adults include:

• Liraglutide
• Orlistat
• Naltrexone-bupropion 6 These therapies have been shown to reduce weight when compared with placebo, with orlistat being effective in significantly reducing fasting blood glucose, HbA1c, total cholesterol, triglycerides, and systolic and diastolic blood pressure 6.

Considerations for Obesity Management

When managing obesity, it is essential to consider:

• Comorbidities accompanying obesity
• Drug interactions
• Risk of negative collateral effects
• Individualized treatments based on the genetic make-up 3
• Patient comorbidities and risk of adverse events when recommending medications for weight loss 6