What are the available medications for weight loss?

From the Guidelines

Weight loss medications should be considered for individuals with a BMI over 30, or over 27 with weight-related health conditions, and can be effective when combined with lifestyle changes, with options including orlistat, phentermine-topiramate, and GLP-1 receptor agonists like liraglutide (Saxenda, starting at 0.6mg daily and increasing to 3.0mg daily) 1.

Key Considerations

• The choice of weight loss medication depends on the patient's medical history, side effect profile, and tolerance to the medication.
• Medications like orlistat (Xenical, 120mg three times daily with meals) and phentermine-topiramate (Qsymia, starting at 3.75mg/23mg daily, increasing to 15mg/92mg if needed) are commonly prescribed options.
• GLP-1 receptor agonists like liraglutide (Saxenda) have been shown to be effective in promoting weight loss and improving glycemic control.

Medication Options

• Orlistat: blocks fat absorption, recommended dose is 120mg three times daily with meals 1.
• Phentermine-topiramate: suppresses appetite, recommended starting dose is 3.75mg/23mg daily, increasing to 15mg/92mg if needed 1.
• Liraglutide (Saxenda): mimics gut hormones to regulate appetite and food intake, recommended starting dose is 0.6mg daily, increasing to 3.0mg daily 1.

Important Notes

• Weight loss medications work best when combined with calorie reduction and increased physical activity.
• Regular monitoring by a healthcare provider is essential to assess effectiveness and manage any side effects.
• The medication should be discontinued if a patient has not achieved significant weight loss (e.g. 5% weight loss at 12 weeks) 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).

Weight Loss Medications: Phentermine is indicated for short-term use as an adjunct in a weight reduction regimen for patients with exogenous obesity and a BMI of 30 kg/m2 or higher, or 27 kg/m2 or higher with other risk factors.

• Key Points:
  • Short-term use (a few weeks)
  • Adjunct to exercise, behavioral modification, and caloric restriction
  • BMI ≥ 30 kg/m2 or ≥ 27 kg/m2 with other risk factors
• Reference: 2

From the Research

Types of Weight Loss Medications

• There are several types of weight loss medications, including orlistat, phentermine-topiramate, naltrexone-bupropion, liraglutide, semaglutide, and tirzepatide, which have been shown to be effective in inducing weight loss 3, 4, 5, 6.
• These medications can be classified according to their mechanisms of action, such as modifying digestive tract absorption, regulating appetite in the brain, or mimicking the actions of enteropancreatic hormones 3.

Efficacy of Weight Loss Medications

• Studies have shown that these medications can lead to significant weight loss, with semaglutide and tirzepatide showing superior efficacy 3, 4, 5.
• The relative potency of adult obesity medications has been studied in meta-analyses, with results showing that semaglutide and tirzepatide are associated with greater weight loss compared to other medications 3.
• For example, semaglutide was associated with 11.4% greater weight loss, and tirzepatide 15 mg was associated with 12.4% greater weight loss, compared to placebo 3.

Safety and Side Effects of Weight Loss Medications

• While these medications can be effective, they can also have side effects, such as gastrointestinal adverse effects, constipation, nausea, and diarrhea 3, 4, 5, 6.
• The incidence of these side effects can vary depending on the medication and the individual patient 3, 4, 5, 6.
• It is essential to weigh the potential benefits of these medications against the potential risks and to monitor patients closely for any adverse effects 4, 5, 6.

Combination with Lifestyle Interventions

• Weight loss medications should be used in combination with lifestyle interventions, such as a moderately reduced-calorie diet and increased physical activity, for optimal results 3, 7, 6.
• Lifestyle modifications are first-line therapy for patients with overweight or obesity, and the most effective weight loss intervention is one that includes a combination of dietary changes, physical activity, and behavior strategies 7.