Drugs for weight loss: part 2

Brief History

The control of obesity with drugs has been a major struggle for more than 3 decades. All types of drugs have been used in the past to treat obesity.
In the past, thyroid hormone and diuretics were often used inappropriately. Dangerous drugs such as dinitrophenol and amphetamines were prescribed, with serious side effects. With better understanding of obesity in the 1980s, different types of weight loss drugs were manufactured. Drugs like fen-fenn helped individuals continue to maintain their weight loss. However, the drug was associated with serious cardiac side effects and its use has been banned universally.

Since then, two new drugs with different mechanisms of action have been approved for use by the FDA. Sibutramine (Meridia) is a serotonin-norepinephrine reuptake inhibitor acts on the appetite center in the brain, and orlistat (Xenical) is a pancreatic lipase inhibitor and inhibits the absorption of fat from the abdomen. However, these drugs do have side effects and their long term complications remain unknown. At present we have a huge gap in our armamentarium to treat obesity.

When does treatment start?

There are various guidelines and most recommend that drug therapy for weight loss should start when an individual has a body mass index (BMI) of > 27 or those who have obesity-related risk factors or co-morbidities, and in obese patients whose life style is severely affected. Under certain circumstances, weight loss drugs may also be effective for other patients. Some physicians also consider using obesity medications to patients with a BMI above 25 who have not responded to a rigorous program combining behavior modification, dietary changes and exercise.

Anti-obesity medications fall into two broad categories based on how they help patients fight fat. One group helps reduce food intake, while the other prevents fat absorption.