Thousands of obese Americans are on the warpath. They've filed lawsuits claiming they have been injured by taking either Pondimin, Redux or Fen-Phen, all slimming drugs.
The drugs can create lesions or abnormalities in the heart valves which can result in abnormal blood flow, sometimes causing major health problems.
The lesions don't usually occur with symptoms, so there is no way a patient will know the drug has caused damage to the heart unless an echocardiogram is carried out. This suggests that the existing lawsuits could be just the tip of a very large iceberg.
American Home Products, the firm responsible for the drug in the US, is "vigorously" disputing the claims, an interesting position as Pondimin (generic name: fenfluramine hydrochloride) has a large warning box at the beginning of its entry in the Physicians' Desk Reference, the American drug bible.
It warns that the drug can cause cardiac disease, and points to one study which discovered that 24 patients who were given a combination drug, including fenfluramine, to treat their obesity developed cardiac disease; five needed surgery. Similar heart disease was found in patients taking fenfluramine on its own.
Primary pulmonary hypertension a rare and often fatal disease has an "increased frequency" in fenfluramine patients, the PDR warning continues.
Common reactions include drowsiness and diarrhoea, while other reactions reported include abdominal pain, fever, suicidal tendencies and death.
As well as pulmonary hypertension, other cardiovascular problems include heart arrest and failure, heart attack, angina and arrhythmia.
To round things off, asthma, paranoia, speech disorder, vertigo and abnormal thinking have all been recorded.
But look on the bright side you don't have to diet.