Drugs approved by the US Food and Drug Administration for treating obesitya
| Drug | Mechanism of action | Contraindications and warnings | Serious interactions | Adverse reactions | Dosage and monitoring | Costb |
|---|---|---|---|---|---|---|
| Phentermine | Suppresses appetite | Contraindications Hyperthyroidism Glaucoma Agitation Pregnancy or breastfeeding (category X) MAO inhibitor within 14 days Use with caution Cardiovascular disease History of drug abuse | Monoamine oxidase (MAO) inhibitors | Nervousness Insomnia Dry mouth | 15, 30, or 37.5 mg daily before breakfast or 1–2 hours after Schedule IV | $12 |
| Orlistat | Inhibits fat absorption | Contraindications Pregnancy or breastfeeding (category X) | Cyclosporine Warfarin Other fat-soluble drugs (see text) | Gastrointestinal: abdominal pain, bowel urgency, steatorrhea, fecal incontinence Hepatotoxicity Oxalate nephropathy | 60 or 120 mg 3 times a day during or within 1 hour of a fat-containing meal Monitor renal function | $530 |
| Phentermine-topiramatec | Phentermine: see above Topiramate: unknown | Contraindications Hyperthyroidism Glaucoma Agitation Pregnancy or breastfeeding (category X) MAO inhibitor within 14 Use with caution Cardiovascular disease History of drug abuse Depression | MAO inhibitors Opioid or other central nervous system depressants CYP3A4 and CYP1A2 inducers | Dry mouth Dizziness Constipation Paresthesia Psychiatric and cognitive adverse events Nephrolithiasis Increased heart rate Angle-closure glaucoma Acute myopia | 3.75/23 mg daily for 14 days, then 7.5/46 mg daily If < 3% weight loss at 12 weeks, increase to 11.25/69 mg daily for 14 days, followed by 15/92 mg daily thereafter Gradually discontinue if < 5% weight loss at 12 weeks on highest dose Pregnancy test at baseline and monthly for women of childbearing age Schedule IV Adjust for renal impairment | $199 |
| Lorcaserin | Suppresses appetite | Contraindications Creatinine clearance < 30 mL/min Pregnancy (category X) Use with caution Creatinine clearance 30–50 mL/min Severe hepatic impairment | Serotonergic agents | Dry mouth Dizziness Somnolence Headache Gastrointestinal disturbance | 10 mg twice a day Discontinue if < 5% weight loss at 12 weeks Monitor blood glucose level closely in patients with diabetes mellitus because of risk of hypoglycemia Schedule IV | $212 |
| Naltrexone bupropion | Suppresses appetite | Contraindications End-stage renal disease Pregnancy or breastfeeding (category X) MAO inhibitor within 14 days Uncontrolled hypertension Seizure disorder Eating disorder | Bupropion Chronic opioid use or acute opiate withdrawa Linezolid CYP2B6 inhibitors | Nausea, vomiting Constipation or diarrhea Headache Dizziness Insomnia Dry mouth | 8/90 mg for 7 days; then twice a day for 7 days; then 2 tablets in morning and 1 tablet in the evening for 7 days, followed by 2 tablets twice a day thereafter Discontinue if < 5% weight loss at 12 weeks Adjust for renal and hepatic impairment | $212 |
| Liraglutide | Slows gastric emptying, increases satiety | Contraindications Personal or family history of medullary thyroid cancer (multiple endocrine neoplasia type 2 syndrome) Pregnancy or breastfeeding (category X) Moderate to severe renal impairment Use with caution History of pancreatitis Severe renal insufficiency | Other hypoglycemic agents | Nausea, vomiting Diarrhea, constipation Hypoglycemia Pancreatitis Gallbladder disease Renal impairment Suicidal thoughts | 0.6 mg subcutaneously daily, increase by 0.6 mg weekly to a daily target dose of 3 mg Discontinue if < 4% weight loss at 16 weeks | $1,095 |
↵a In various trials, these drugs led to weight loss of 5.0 to 12.9 kg compared with placebo.
↵b Average wholesale cost for 1 month, per Healthcare Bluebook. https://healthcarebluebook.com/page_ConsumerFront.aspx.
↵c Prescribers must complete Healthcare Provider Training Program and HCP Registration Form before they can prescribe this medication; see www.qsymiarems.com/.