What other medications can be used for medical weight loss?

FDA-Approved Medications for Medical Weight Loss

Several FDA-approved medications are available for medical weight loss, with options including phentermine, orlistat, phentermine/topiramate, naltrexone/bupropion, liraglutide, and semaglutide, each with different mechanisms of action and safety profiles. 1

Short-Term Medications

Phentermine

• Mechanism: Sympathomimetic amine that suppresses appetite through norepinephrine release 1
• Dosing: 15-37.5 mg once daily in the morning; low-dose 8 mg tablets can be taken up to 3 times daily 1
• Efficacy: Average 6.0 kg weight loss over 28 weeks; 46% of patients achieve ≥5% weight loss 1
• FDA approval: Short-term use (≤12 weeks), though often prescribed longer off-label 1
• Best candidates: Younger patients without cardiovascular disease or uncontrolled hypertension 1
• Avoid in: Patients with anxiety, insomnia, active coronary disease, uncontrolled hypertension 1
• Common side effects: Dry mouth, insomnia, dizziness, irritability 1
• Contraindications: History of cardiovascular disease, use with MAOIs, hyperthyroidism, glaucoma, agitated states, pregnancy 2

Long-Term Medications

Orlistat

• Mechanism: Inhibits gastrointestinal lipases, reducing fat absorption by approximately 30% 1
• Dosing: 120 mg three times daily with meals (prescription); 60 mg three times daily (OTC as Alli) 1
• Best candidates: Patients with obesity and constipation 1
• Side effects: Gastrointestinal issues related to steatorrhea 1
• Special considerations: Requires multivitamin supplementation due to reduced absorption of fat-soluble vitamins 1
• Contraindications: Organ transplant recipients, chronic malabsorption syndromes 3

Phentermine/Topiramate Extended-Release (Qsymia)

• Mechanism: Combination therapy targeting multiple pathways - appetite suppression and decreased food intake 1
• Dosing: Gradual titration starting with 3.75/23 mg daily for 14 days, then 7.5/46 mg daily 1
• Efficacy: 8.4% weight loss at 56 weeks with 7.5/46 mg dose; 10.6% with 15/92 mg dose 4
• Discontinuation criteria: If <3% weight loss after 12 weeks at 7.5/46 mg or <5% after 12 weeks at 15/92 mg 1

Naltrexone/Bupropion Sustained-Release (Contrave)

• Mechanism: Activates POMC neurons in arcuate nucleus, affecting feeding and weight control 1
• Dosing: Start with 1 tablet daily, increase weekly to maximum of 2 tablets twice daily (32/360 mg) 1
• Discontinuation criteria: If <5% weight loss at 12 weeks 1

Liraglutide (Saxenda)

• Mechanism: GLP-1 analog that reduces appetite, increases satiety, and delays gastric emptying 1
• Dosing: Subcutaneous injection starting at 0.6 mg daily, increasing by 0.6 mg weekly to 3.0 mg 1
• Discontinuation criteria: If <4% weight loss at 16 weeks 1

Semaglutide (Wegovy)

• Mechanism: GLP-1 receptor agonist 1
• FDA approval: For chronic weight management in adults with BMI ≥27 kg/m² with weight-related comorbidities 1

Clinical Considerations

Patient Selection

• Appropriate for individuals with BMI ≥30 kg/m² or ≥27 kg/m² with weight-related comorbidities 1
• Medications should be used as adjuncts to diet, exercise, and behavioral therapy 1
• Consider medication effects on existing comorbidities when selecting agents

Monitoring and Expectations

• Assess efficacy and safety at least monthly for the first 3 months 1
• Realistic weight loss expectations: 5-10% body weight in successful patients 1
• Continue medication if achieving target weight loss; discontinue if inadequate response or significant side effects 1

Common Pitfalls

1. Unrealistic expectations: Inform patients that pharmacotherapy typically yields 5-10% weight loss, not complete normalization of weight 1
2. Medication interactions: Review concomitant medications carefully, especially those that may promote weight gain 1
3. Pregnancy concerns: Weight loss medications are contraindicated during pregnancy and require reliable contraception in women of reproductive potential 1
4. Discontinuation syndrome: Abrupt cessation may lead to rebound weight gain; emphasize long-term approach 1

Remember that obesity is a chronic disease requiring long-term treatment. The goal of pharmacotherapy is not only weight reduction but also improvement of obesity-related comorbidities such as diabetes, hypertension, and dyslipidemia 1.