Interneuron To Alter Obesity Drug Labeling

Interneuron will change the label on its Redux (dexfenfluramine) antiobesity drug to reflect a much greater risk of primary pulmonary hypertension, a potentially fatal lung disorder. The original label, issued when the drug was approved in April, estimated that 18 people per million who take the drug for over three months would get the disease, but a recalculation by American Home Products, which is marketing the drug, put the figures at 23-46 people per million, compared with one to two in the general population. Both companies have stressed that the risks are small and that the benefits outweigh the risks.

About one year ago, the US Food and Drug Administration recommended rejection of the drug, but reversed its decision in December 1995. A study due to be published soon will look at whether antiobesity drugs put patients at a much higher risk of pulmonary hypertension, and a study published in the New England Journal of Medicine (August 29) has suggested that the incidence of the disorder was nearer 55 people per million in patients who had taken the drugs for between three and 12 months. The risk appeared to increase the longer the patients took the drugs.