Obesity is a major health problem for approximately a third of U.S. adults, increasing their risk of heart attack, diabetes, stroke, and hypertension. Absolute proof that Adipex can prevent these illnesses does not exist, but this drug combination helped some patients to lose weight, particularly if they participated in a supervised weight-loss program that included nutrition advice and exercise.

The Food and Drug Administration (FDA) had approved this drug for individual use years ago, but its use had never been approved.

Earlier reports had indicated that Adipex was associated with a very serious illness called primary pulmonary hypertension, a rare but frequently lethal disorder that occurs in only one of many thousands of patients taking these drugs. In this condition, the blood vessels that supply the lungs become thickened and scarred. Because these vessels gradually stiffen, the heart has to work harder and harder to pump blood into the lungs.

The new information points out the risk of using drugs for cosmetic reasons. People who are not severely obese will receive no medical value from Adipex. Some epidemiologists initially believed that the potential benefits from Adipex for severely obese patients outweighed the risk of developing primary pulmonary hypertension. They estimated that for every million obese patients who take Adipex, 280 lives would be saved by weight loss while 14 would be lost due to pulmonary hypertension. But this was before the valve problems came to light.