Obesity drugs pulled from the market due to reports of heart complications may also have played a role in the rise in the number of cases of a rare lung disorder in the US.

Dexfenfluramine and fenfluramine are anti-obesity drugs withdrawn from the market by the Food and Drug Administration in 1997 due to their potential to cause heart problems. These drugs have also been linked to a serious lung disorder, primary pulmonary hypertension. This is a rare, life-threatening disease of unknown cause in which the blood pressure in large arteries in the lung is abnormally high, leading to problems with breathing and heart function. To save their lives, patients may need to have a heart-lung transplant.

This study found that death rates due to primary pulmonary hypertension in the US have increased since 1979, especially among black women. The authors say that anorexigens, a class of drug of which fenfluramines are a member, may be responsible for "some portion of this increase."

The investigators found that deaths due to the disorder have "increased notably" since 1979. Among adults, mortality from primary pulmonary hypertension was higher in blacks than in whites and in women than in men. Black women had the highest mortality rate, at nine deaths per one million people, and they also have shown the steepest rise in death rates from the disease during this period.

Patients who had used fenfluramines longer than 6 months had an increased risk of developing primary pulmonary hypertension. The risk increased with longer duration of use compared with shorter-term usage and was higher in recent users.

Chest 2000;117:796-800, 870-874