| Liraglutide (Saxenda) | No specified time limitation. | GLP- 1 receptor agonist; increases insulin secretion, decreases glucose production, slows down gut motility and gastric emptying, and works on hypothalamus to enhance early satiety. | Adding to lifestyle modifications resulted in placebo subtracted average weight loss of 5.4% from baseline weight.
Average weight loss 3.9 to 5.2 kg (8.1 to 11.4 lbs) more than placebo at 56 weeks.
44 – 62% of patients reached weight loss goal of 5% or greater by 56 weeks (depending on patient population). | Nausea, vomiting, diarrhea, constipation, abdominal pain, dyspepsia, injection site reactions, headache, cholelithiasis, pancreatitis (rare), hypoglycemia in patients with diabetes taking hypoglycemic medications
1 in 18 patients in clinical trials stopped taking liraglutide (3 mg) due to side effects. | Contraindicated in pregnancy and in those with a personal or family history of medullary thyroid cancer or multiple endocrine neoplasia syndrome type 2.
Increased risk for hypoglycemia in patients with diabetes; may require adjustment of antidiabetic medications. | Injectable (multi-dose pen).
Dose escalation recommended to minimize side effects: Initiate 0.6 mg daily x 1 week, then increase by 0.6 mg daily at weekly intervals to a target dose of 3 mg once daily. | $90–450 (maintenance dose). |
| Naltrexone/Bupropion ER (Contrave) | Assess response to therapy after 12 weeks at maintenance dosage. If patient has not lost at least 5% of baseline body weight, discontinue treatment. | Mechanism not well understood, but the hypothalamic melanocortin system and the mesolimbic reward system are thought to be the primary targets. | Adding to lifestyle modifications resulted in placebo subtracted average weight loss of 4% from baseline.
Average weight loss ≤ 4.1 kg (9 lbs) more than placebo at 56 weeks.
< 50% of patients in clinical trials reached the weight loss goal of 5% or greater by one year. | Nausea, vomiting, diarrhea, constipation, headache, insomnia or sleep disorder, dizziness, anxiety, depression, seizure, increase in blood pressure and heart rate, dry mouth, tremor, open angle glaucoma.
1 in 9 patients in clinical trials stopped taking naltrexone/bupropion ER due to side effects. | Contraindicated in pregnancy.
Hypersensitivity to bupropion or naltrexone.
Use with caution in patients with history of seizures, serious psychiatric illness, drug or alcohol misuse, or eating disorders. | Available as naltrexone 8 mg/bupropion 90 mg ER tablets.
Initiate 1 tab every morning x 1 week, then 1 tab twice daily x 1 week, then 2 tabs every morning + 1 tab every evening x 1 week, then 2 tabs twice daily thereafter.
Maintenance dose: naltrexone 16 mg/bupropion 180 mg.
Maximum daily dose: naltrexone 32 mg/bupropion 360 mg. | $300 (maintenance dose).
Note: Naltrexone and bupropion are often prescribed separately at different doses; cost will vary. |
| Orlistat (Alli, Xenical) | No time limitation. Continue treatment if weight loss of 5% at 12 weeks (4 pounds every 4 weeks). If no weight loss, benefit is unlikely from continuing. | Prevents absorption of fat. | Adding to lifestyle modification results in an average 4–7 pounds of additional weight loss in a year. | Gastrointestinal side effects (flatulence, greasy stools) are significant and limit compliance. Risk of vitamin deficiencies. Rare cases of liver disease. | Contraindicated in pregnancy, patients with malabsorption disorders, reduced gallbladder function.
Use cautiously in patients with obstructed bile duct, impaired liver function, or pancreatic disease. | Capsules
OTC: 60 mg tabs. Take with meals that contain fat up to three times per day. Avoid foods with high fat content to minimize gastrointestinal side effects.
120 mg three times per day. | Alli (OTC) $75
Xenical $630 |
| Phentermine (several brands) | Short-term: 3 months | Appetite suppressant and sympathomimetic agent | 3–5% weight loss from baseline. | Monitor blood pressure and heart rate closely. Constipation, dry mouth, and insomnia. | Contraindicated in pregnancy, patients older than 65 years of age, and patients with a history of drug misuse.
Relative contraindications are heart disease, high blood pressure, arteriosclerosis, hyperthyroidism, diabetes, glaucoma.
Use cautiously in patients on SSRIs, MAO inhibitors, tricyclic antidepressants, and stimulants. | Tablets and extended-release capsules.
Either:
8 mg three times daily. Take each dose 30 minutes before meals, with the last dose being taken at least 4–6 hours before bedtime to prevent insomnia.
15–37.5 mg once daily. Take the dose before breakfast or 1–2 hours after breakfast. | $47–70
Generic: $14–60 |
| Phentermine + Topiramate (Qsymia) | Extended use (dose of phentermine in this combination is lower than when phentermine is used as a single agent) | Phentermine: reduced appetite and reduced food consumption
Topiramate: appetite suppression and increased satiety | Adding to lifestyle modifications results in approximately 5–10% weight loss in a year. | Paresthesias, dizziness, dysgeusia (distorted sense of taste), insomnia, constipation, and dry mouth | Contraindicated in pregnancy, patients older than 65 years of age, and patients with a history of drug misuse. Topiramate is teratogenic.
Relative contraindications are heart disease, high blood pressure, arteriosclerosis, hyperthyroidism, diabetes, glaucoma.
Use cautiously in patients on SSRIs, MAO inhibitors, tricyclic antidepressants, and stimulants. | Capsules (extended-release)
Once daily in the morning.
3.75 mg (phentermine)/23 mg (topiramate) daily for 14 days, then increase to 7.5 mg/46 mg. Max dose is 15 mg/92 mg.
Discontinue (or escalate) if 3% weight loss not achieved in 12 weeks on 7.5 mg/46 mg dose.
Discontinue gradually if 5% weight loss not achieved after 12 weeks on maximum dose. | $198 |
