Summary

AGA 2022 guideline on pharmacologic management of adults with obesity (BMI ≥30, or ≥27 with weight-related complications) who have inadequate response to lifestyle intervention. Strongly recommends adding long-term pharmacotherapy to lifestyle changes; conditionally suggests semaglutide 2.4 mg, liraglutide 3.0 mg, phentermine-topiramate ER, and naltrexone-bupropion ER (moderate certainty), and phentermine and diethylpropion (low certainty). Suggests against orlistat; Gelesis100 hydrogel only in clinical trial setting. Semaglutide prioritized for most patients based on magnitude of net benefit.

Key Recommendations

Add pharmacotherapy to lifestyle intervention in adults with BMI ≥30 kg/m² or ≥27 kg/m² with weight-related complications who have inadequate response to lifestyle alone (strong recommendation).
Prioritize semaglutide 2.4 mg SQ weekly over other AOMs for most patients given largest magnitude of weight loss (~10.8% TBWL vs placebo).
Use liraglutide 3.0 mg SQ daily as an alternative GLP-1 RA option with glucoregulatory benefits; titrate to mitigate GI adverse effects.
Use phentermine-topiramate ER preferentially in patients with comorbid migraines; avoid in cardiovascular disease, uncontrolled hypertension, and pregnancy (topiramate teratogenic).
Use naltrexone-bupropion ER preferentially in patients with depression or attempting smoking cessation; avoid with seizure disorders and concomitant opiates.
Suggest against orlistat due to modest benefit and high GI adverse effect burden; reasonable only for patients prioritizing small weight loss over GI tolerability.
Phentermine and diethylpropion suggested for use with lifestyle intervention despite FDA short-term (12-week) labeling, often used off-label long-term; avoid in cardiovascular disease.
Discontinue AOM if <5% TBWL after 12 weeks at maintenance dose (poor responder) — applies to phentermine-topiramate ER and naltrexone-bupropion ER.
Monitor blood pressure and heart rate periodically with phentermine, diethylpropion, phentermine-topiramate ER, and naltrexone-bupropion ER (especially first 12 weeks).
Counsel women of childbearing potential on phentermine-topiramate ER to use effective contraception due to topiramate teratogenicity.
Supplement orlistat users with daily multivitamin containing fat-soluble vitamins (A, D, E, K) taken ≥2 hours apart from the drug.
Use Gelesis100 oral superabsorbent hydrogel only within a clinical trial (knowledge gap).

Thresholds & Doses

Eligibility for AOM: BMI ≥30 kg/m², or ≥27 kg/m² with weight-related complications, plus inadequate response to lifestyle intervention.
Lifestyle target: 500–600 kcal/day deficit plus ≥150 min/week physical activity.
FDA efficacy threshold: ≥5% TBWL at 1 year; MCID for guideline = MD ≥3% TBWL over placebo.
Semaglutide titration: 0.25 mg weekly × 4 wk → 0.5 → 1.0 → 1.7 → 2.4 mg weekly (maintenance reached at 16 weeks); mean weight loss ~10.8% vs placebo.
Liraglutide titration: 0.6 mg daily × 7 days → 1.2 → 1.8 → 2.4 → 3.0 mg daily (maintenance at 4 weeks); mean weight loss ~4.8% vs placebo.
Phentermine-topiramate ER: start 3.75/23 mg daily × 14 days → 7.5/46 mg daily; if <3% weight loss at 12 weeks, escalate to 11.25/69 mg × 14 days → 15/92 mg daily; mean weight loss ~8.5% vs placebo at 15/92 mg.
Phentermine-topiramate ER: discontinue if <5% TBWL after 12 weeks at maximum dose; taper every-other-day for ≥1 week to reduce seizure risk.
Naltrexone-bupropion ER (8 mg/90 mg tablets): titrate weekly 1 tab AM → 1 AM + 1 PM → 2 AM + 1 PM → 2 tabs BID; discontinue if <5% TBWL at 12 weeks.
Naltrexone-bupropion ER dose adjustments: max 1 tab BID in moderate-severe renal impairment; max 1 tab daily in moderate-severe hepatic impairment; avoid in ESRD.
Orlistat: 120 mg PO TID with meals (60 mg OTC); multivitamin ≥2 hours apart; mean weight loss ~2.8% vs placebo.
Phentermine: up to 37.5 mg daily (capsules 15/30/37.5 mg; tablets 8/37.5 mg); 8-mg tablets up to TID 30 min before meals; mean weight loss ~3.6% vs placebo.
Diethylpropion: 25 mg IR TID before meals or 75 mg ER once daily AM; mean weight loss ~5.4% vs placebo.
Gelesis100: 3 capsules (2.25 g) with water before lunch and dinner; indication BMI 25–40 kg/m²; mean weight loss ~2% vs placebo.
Hold phentermine and phentermine-containing drugs ≥4 days before procedures requiring anesthesia.
Stop AOMs ≥14 days from MAO inhibitor use; avoid in untreated hyperthyroidism (phentermine, diethylpropion).

Citations

Table 1 (Recommendations 1–9) — strength and certainty of all 9 recommendations
Recommendation 1 — strong recommendation for adding pharmacotherapy to lifestyle in BMI ≥30 or ≥27 with complications
Recommendation 2 & Table 4 — semaglutide 2.4 mg evidence (MD 10.76% TBWL; 8 RCTs)
Recommendation 3 — liraglutide 3.0 mg evidence (MD 4.81% TBWL; 11 RCTs) and titration schedule
Recommendation 4 — phentermine-topiramate ER dosing, hypertension considerations, and teratogenicity warning
Recommendation 5 — naltrexone-bupropion ER use in depression/smoking cessation; seizure and opiate cautions
Recommendation 6 — conditional recommendation against orlistat; multivitamin and hepatotoxicity warnings
Recommendations 7 & 8 — phentermine and diethylpropion low-certainty evidence and off-label long-term use considerations
Recommendation 9 — Gelesis100 hydrogel restricted to clinical trial use (knowledge gap)