weight reducing medicines,their efficacy and side effects

Weight loss drugs should be started if BMI(body mass index) more than or equal to 27 kg/m2 with one or more obesity associated co-morbid conditions (e.g., type 2 diabetes. hypertension, and dyslipidemia) and by patients with BMI more than equal to 30 kg/m2 who are motivated to lose weight.The approved drugs are:
1.Orlistat
Doses- 60mg or 120mg three times a day (during or up to 1 h after a  meal)
Average weight loss in one year-2.5 kg (60 mg); 3.4 kg (120 mg)
Common side effects- Abdominal pain/discomfort, oily spotting/stool, fecal urgency, flatulence, malabsorption of fat soluble vitamins (A, D, E, K) and medications (e.g., cyclosporine, thyroid hormone replacement, or anticonvulsants),potentiation of the effects of warfarin
Uncommon/serious side effects-Liver failure and oxalate nephropathy.

2.Lorcaserin
Dose- 10 mg twice daily
Average weight loss in one year-  3.2 kg
Common side effects- Hypoglycemia, headache, fatigue
Uncommon/serious side effects-Serotonin syndrome , suicidal ideation, heart valve disorder ,bradycardia

3.Phentermine/topiramate combination
Dose: 3.75 mg/23 mg once a day for 14 days, then increase to 7.5 mg/46 mg once a day. Maximum dose: 15 mg/92 mg once a day.
Average weight loss in one year- 6.7 kg with 7.5 mg/46 mg dose; 8.9 kg with 15 mg/92 mg
Common side effects-Paresthesia, xerostomia(dry mouth), constipation, headache
Uncommon/serious side effects-Topiramate is teratogenic and has been associated with cleft lip/palate

4.Naltrexone/bupropion combination
Dose- 8 mg/90 mg tabs Maximum dose: two tablets  twice daily for a total daily dosage of naltrexone 32 mg/bupropion 360 mg
Average weight loss in one year-2.0–4.1 kg with 32 mg/360 mg
Common side effects-Nausea, constipation, headache, vomiting
Uncommon/serious side effects-Depression,precipitation of mania, contraindicated in patients with a seizure disorder

5.Liraglutide (injection in pen form)
Dose: 3 mg s.c. once a day (maintenance dose achieved after starting from lower doses)
Average weight loss in one year-5.8–5.9 kg
Common side effects-Hypoglycemia, nausea, vomiting, diarrhea, constipation, headache
Uncommon/serious side effects-Pancreatitis, thyroid C-cell tumors in rodents, contraindicated in patients with personal/family history of medullary thyroid carcinoma or MEN2(multiple endocrine neoplasia), acute renal failure