WEIGHT LOSS MEDICATION

Your doctor may recommend starting on medication to assist in weight loss if your BMI exceeds 27.5 kg/m2. If you have other chronic medical conditions such as diabetes, coronary artery disease, hyperlipidaemia or obstructive sleep apnoea, medication may even be considered when BMI is between 25 to 27.4 kg/m2.

Sibutramine (Reductil) (use in Singapore suspended in October 2010)

Sibutramine was approved for use in the US in 1997. The longest published study on sibutramine is from the STORM (Sibutramine Trial of Obesity Reduction and Maintenance) Study Group. The weight loss at the end of 2 years was 10.2 kg compared with 4.7 kg in the control group.

However, in 2010, the Health Sciences Authority (HSA) of Singapore decided to suspend sibutramine after taking into consideration the results of the SCOUT (Sibutramine Cardiovascular Outcomes) study.  The SCOUT study was a 6 year post-marketing study, involving approximately 10,000 patients.  It was found that patients treated with sibutramine experienced a significant increased risk of serious cardiovascular adverse events, such as stroke and heart attacks.

Side effects include: dry mouth, insomnia, headaches and constipation.

Orlistat (Xenical)

Orlistat was approved in the US in 1999. It works by reducing the absorption of dietary fat by about 30%. On average, subjects on Orlistat lose 10% of their body weight compared to 6% weight loss in control subjects (Davidson MH, Hauptman J, DiGirolamo M, et al. Weight control and risk factory reduction in obese subjects treated for 2 years with orlistat: a randomized controlled trial. Jama 1999;281(3):235-42).

Side effects include: flatulence with discharge, oily spotting, increased urge to defaecate with occasional incontinence in some.

Orlistat can also cause loss of fat soluble vitamins A,D,E and K, as well as beta carotenes and some of the other carotenoids. As such, patients who are on regular orlistat should ensure intake of vitamin supplements and there should be a gap of at least 2 hours between supplements and orlistat intake.

BARIATRIC ("WEIGHT LOSS") SURGERY

Surgery should be considered only in the morbidly obese (BMI > 40 mg/m2) or in those with chronic medical problems who are severely obese (BMI > 35 mg/m2).

There are 2 approaches adopted:

1. Reduce the volume of the stomach to produce an earlier sense of satiation (procedures performed include adjustable gastric banding and vertical banded gastroplasty).

2. Reduce the length of bowel that comes into contact with food, thereby reducing it's absorption capacity (procedures include gastric bypass surgery).

Surgery in generally has been shown to produce a weight loss of about 50% of excess weight, and this weight loss is maintained in 60% of patients even after 5 years. Associated with this weight loss would be an improvement of co-morbid conditions such as Hypertension, Hypercholesterolaemia, Type II Diabetes Mellitus, Glucose Intolerance, Obstructive Sleep Apnoea and Metabolic Syndrome.