What medication can be used to suppress appetite?

Medications for Appetite Suppression

Phentermine is the most effective first-line medication for appetite suppression in appropriate candidates, with a recommended dosage of 15-37.5 mg once daily in the morning. 1, 2

FDA-Approved Medications for Appetite Suppression

First-Line Options:

1. Phentermine

   • Mechanism: Adrenergic agonist that activates the sympathetic nervous system
   • Dosing: 15-37.5 mg once daily in the morning (can start with lower doses like 9.375 mg)
   • Efficacy: 5.1-6.0% weight loss at 28 weeks 1
   • Status: Schedule IV controlled substance
   • Duration: FDA-approved for short-term use (≤12 weeks) but often prescribed longer off-label
   • Best candidates: Younger patients without cardiovascular disease who need appetite suppression

2. Orlistat (Xenical/Alli)

   • Mechanism: Lipase inhibitor that blocks ~30% of dietary fat absorption
   • Dosing: 120 mg TID with meals containing fat
   • Efficacy: 3.1-5.6% weight loss at 1 year 1
   • Status: Not controlled
   • Best candidates: Patients with hypercholesterolemia or constipation

Combination/Advanced Options:

1. Phentermine/topiramate ER (Qsymia)

   • Mechanism: Adrenergic agonist + neurostabilizer
   • Dosing: Start 3.75/23 mg daily, titrate up as needed
   • Efficacy: 7.8-10.9% weight loss at 1 year 1
   • Status: Schedule IV controlled substance
   • Best candidates: Patients needing greater weight loss efficacy

2. Lorcaserin (Belviq)

   • Mechanism: Serotonin 5-HT2C receptor agonist
   • Dosing: 10 mg BID
   • Efficacy: 3.6-5.8% weight loss at 1 year 1
   • Status: Schedule IV controlled substance
   • Best candidates: Patients reporting inadequate meal satiety

3. Naltrexone/bupropion SR (Contrave)

   • Mechanism: Opioid receptor antagonist + dopamine/norepinephrine reuptake inhibitor
   • Dosing: Gradual titration to 16/180 mg BID
   • Efficacy: 4.8-6.4% weight loss at 1 year 1
   • Status: Not controlled
   • Best candidates: Patients with food cravings, trying to quit smoking, or with depression

4. Liraglutide 3.0 mg (Saxenda)

   • Mechanism: GLP-1 receptor agonist
   • Dosing: Start 0.6 mg daily, titrate weekly to 3.0 mg
   • Efficacy: 5.4-8.0% weight loss at 1 year 1
   • Status: Not controlled
   • Best candidates: Patients with type 2 diabetes, prediabetes, or inadequate meal satiety

Patient Selection Algorithm

1. Determine eligibility:

   • BMI ≥30 kg/m² without comorbidities, or
   • BMI ≥27 kg/m² with weight-related comorbidities (hypertension, diabetes, dyslipidemia, sleep apnea)

2. Screen for contraindications:

   • For phentermine-based medications: cardiovascular disease, uncontrolled hypertension, hyperthyroidism, glaucoma, anxiety, insomnia, MAOIs use, history of drug abuse
   • For specific contraindications to other medications, see individual drug profiles

3. Select medication based on patient profile:

   • No comorbidities, needs appetite control: Phentermine
   • Cardiovascular disease: Orlistat or lorcaserin
   • Type 2 diabetes: GLP-1 agonist (liraglutide)
   • Hypercholesterolemia/constipation: Orlistat
   • Food cravings/addictive eating behaviors: Naltrexone/bupropion
   • Depression or smoking cessation: Naltrexone/bupropion

Monitoring and Follow-up

• Assess efficacy and safety monthly for the first 3 months, then every 3 months
• Discontinue medication if <5% weight loss after 12 weeks on maximum tolerated dose
• Consider alternative medication if inadequate response

Important Caveats

1. Medications should not be used alone but in combination with lifestyle modifications including diet and exercise 1

2. Tolerance development: Effectiveness of appetite suppressants may diminish with chronic administration 3, requiring dose adjustment or medication rotation

3. Cardiovascular risk: Avoid sympathomimetic agents (phentermine, phentermine/topiramate) in patients with cardiovascular disease 1

4. Pregnancy: All anti-obesity medications are contraindicated in pregnancy (category X) 1

5. Short-term approval: Despite common off-label long-term use, phentermine is only FDA-approved for short-term use (≤12 weeks) 2

6. Realistic expectations: Patients should understand that typical weight loss with medication is 5-10% of body weight, though individual results may vary 1