Pharmacotherapy for obesity
Obesity is a serious, chronic, relapsing disease of energy regulation, with strong genetic and early-life environmental determinants.
Medications can be useful adjunct to lifestyle intervention in effecting and maintaining clinically significant weight loss in those with BMI >30, or 27-30 and obesity-related complications.
*Check BMI here.
Safety and efficacy should be monitored closely on commencement and the medication should be discontinued if there are safety or tolerability issues, or if <5% weight loss is observed after 3-4 months
For the majority of patients, following the exemplary diet and exercise recommendation provide only modest or no weight loss and difficulty to sustain.
| Drug | Starting dose | Available doses | Weight loss vs placebo (% or kg) | Side Effects | Contraindications | |
| Phentermine | 15 mg | 15, 30, 40 mg | 3.6-4.5 kg in 6 months | Insomnia, dry mouth, agitation, tachicardia | Hypertension, glaucoma, history drug/alcohol abuse, SSRI antidepressants, pregnancy, heart disease | |
| Orlistat | 120 mg TDS | 120 mg | 2.9-3.4% in 1 year | Steatorrhea, oil spotting, flatulence, incontinence, vitamin malabsorption | pregnancy | |
| Liraglutide | 0.6 mg | 0.6 – 3 | 5.4% in 1 year | Nausea, Rare pancreatitis, cholecystitis | Renal/hepatic insufficiency, pregnancy, psychiatric disorder, past pancreatitis | |
| Naltrexone/Bupropion | 8/90 mg | 4.8% in 1 year | Nausea, headache, dizzy and dry mouth | Antidepressants, | ||
| Topiramate | 12.5 mg mane | 25, 50, 100 mg | 3.4-5 kg | Insomnia, dry mouth, paraesthesia, altered taste, dizziness, depression | Glaucoma, renal stones, pregnancy | Off label |
| Phentermine/topiramate | 15 mg/12.5 mg mane | 15/12.5- 100 mg | 5-6.6% in 1 year | As above | As above | Off label |
| Metformin | 500 mg | 500-2000 mg | 0.6-1.2 kg | Bloating, diarrhea, Vit B12 deficiency, hypoglycemia | Renal problems | Off label |
| SGLT-2 (dapagliflozin, canagliflozin, empagliflozin) | 1.8 – 2.7 kg | Genital and urinary tract infections | Renal problems | Off label |
