Subsequently, FDA issued a Public Health Advisory to over 700,000 health care practitioners and institutions warning them of this new concern with these products. These reports have been from 23 different states. Sixteen of these 82 patients required surgery to repair their heart valves. At least one of these patients died following surgery to repair the valves. However, no reports have yet been received of these heart problems developing when fenfluramine or phentermine are used as single agents for the duration presently approved.
Some epidemiologic studies using on-going trials and various data bases are already underway.
Other prospective studies are presently being designed. The agency therefore has requested the manufacturers of these products to revise the drugs' approved labels to emphasize the new safety information in a prominent, black boxed warning at the beginning of the label. This new black box warning will warn prescribers of these new concerns and reiterate the fact that the safety and efficacy of the combined use of these products and the use of the products for longer than presently approved has not been established. In addition, the FDA has requested that manufacturers quickly develop patient package inserts to alert potential users to the same facts and concerns. FDA continues to be highly concerned about these reports of serious heart problems in association with the use of these products.