Prescription Weight Loss Medicine (cont.)
In the mid 1990s doctors also prescribed the popular appetite suppressant Redux or the combination of phentermine and fenfluramine, called "Phen-fen." However fenfluramine (Pondimin) and Redux were withdrawn from the market in 1997 because they caused damage to heart valves. Phentermine is still available. Taking phentermine alone has not been associated with the adverse health effects of the fenfluramine-phentermine combination.
Another type of prescription weight loss drug is a fat absorption inhibitor. Xenical is the only example of this type of treatment approved for use in the U.S. Xenical works by blocking about 30% of dietary fat from being absorbed, and is the most recently approved weight loss drug.
Meridia and Xenical are the only weight-loss medications approved for longer-term use in significantly obese people, although the safety and effectiveness have not been established for use beyond 1 year.
How Do Appetite Suppressants Work?
Appetite suppressants promote weight loss by tricking the body into believing that it is not hungry or that it is full. They decrease appetite by increasing serotonin or catecholamine -- two brain chemicals that affect mood and appetite.
How Do Fat Absorption Inhibitors Work?
Fat-absorption inhibitors work by preventing your body from breaking down and absorbing fat eaten with your meals. This unabsorbed fat is eliminated in bowel movements.
Do Prescription Weight Loss Drugs Really Work?
In general, Xenical and Meridia are moderately effective, leading to an average weight loss of 5 to 22 pounds over a 1 year period, more than what would be expected with non-drug treatments. However, the response to these medications is based on each individual, and some people experience more weight loss than others. Likewise, there is no one correct dose for these medications. Your doctor will decide what works best for you based on his or her evaluation of your medical condition and your response to treatment.
Some people have lost more than 10% of their initial body weight with the help of prescription medications. This is a large enough amount to reduce the risk of high blood pressure, diabetes and other obesity-related health complications . Patients generally experience a maximum weight loss within 6 months of starting medication treatment.
Over the short term, weight loss due to prescription drugs may reduce a number of health risks in obese individuals. However, there are currently no studies to determine the effects of these medications over the long term.