Obesity, defined as a body mass index of more than 30 kg/m2, is a worldwide epidemic. It is the major contributor to diabetes, hypertension and heart disease. Individuals with obesity are at greater risk of morbidity (poor health) and mortality (death) compared to individuals of normal weight. The focus of public health intervention should be the prevention of this problem in future generations and clinicians should assist those who suffer with interventions to help with weight loss.

Diet, regular exercise and behavior modifications are effective in select groups but for those with obesity other interventions maybe required. Medications and surgery are readily available options for managing obesity and morbid obesity but they are not without risks. Individuals who have a BMI more than 30 or who have a BMI 27-29 who has certain medical conditions are considered candidates for medical management.

Drugs are not a permanent solution for weight management but an option to initiate weight loss and/or to supplement the efforts of diet and exercise. In addition, currently available drugs have a number of concerns including limited effectiveness, side effects, the potential for adverse events and cost. All these factors should be taken into consideration when electing to utilize medication to assist with weight loss. Individuals are candidates for medication use if they are obese or if they are overweight with medical conditions that place them at high risk of serious outcomes in the future and other interventions have not been effective.

Drugs shouldn’t be used in isolation but as an adjunct to regular exercise, proper diet and behaviour modification. An effective weight loss program should show a drop in body weight by 5-10% because this is the point where health benefits are seen. Expected weight loss usually exceeds 2kg per month (1 lb per week) dropping to more than 5% below baseline weight at the 3-6 month period. Drug trials using both drug and behavior modification view a weight loss of 10-15% as a good response and more than 15% as excellent response.

There are 2 drugs available that have a proven efficacy and a reasonable safe profile: Orlistat and Lorcaserin. Other drugs have been used with varying effects. The most popular were the sympathomimetic agents such as phentermine, which acts at the level of the brain, causing early satiety. This medication increases blood pressure and heart rate with the potential for serious adverse events in those with cardiovascular problems. Certain antidepressant and anti-seizure medications have been utilized to aid weight loss. In addition certain diabetic medications like metformin have reported benefits in weight management in those with Type II diabetes.

Orlistat is the recommended first line medication. It inhibits the enzyme, pancreatic lipase, thus preventing the digestion of fat. The dose is 120 mg three times a day. Drug trials showed an average weight loss of 5-10 kg in those taking this drug compared to 3-6 kg for control subjects. Typical side effects are related to the gastrointestinal tract and include nausea, gassiness, flatus, and loose and oily stools. It can be used up to 2-4 years and generally has no other major effects. The only concern of note is that it may decrease the absorption of fat-soluble vitamins, so supplements are encouraged.

Lorcaserin is a serotonin agonist with efficacy equivalent to Orlistat. It should be considered in individuals who have intolerable side effects on Orlistat. It works by decreasing the appetite. The dose is 10 mg twice daily and the reported side effects include headache, nausea and back pain. Long-term safety data is limited.
Combination drugs such as phentermine-topiramate and bupropion-naltrexone are available for use if the other preferred drugs are not effective. There are many concerns related to these combination drugs and a physician with the appropriate expertise should monitor their use.

Obesity is one of the most pressing public health issues of developed countries. The good news is that it can be managed. Efforts should focus on preventing this problem in future generations and providing the current generation with treatment options. Medications are only one tool in the armamentarium to fight obesity and their use should be done under the guidance of health care providers with appropriate training and expertise.

I hope this article has provided you with information that will help you make wise choices, so you may:

Live healthy, live well and live long!