One 29-year-old woman, who had taken a combination of two appetite suppressants for just 23 days, died of pulmonary hypertension - increased resistance to the flow of blood through the lungs.
The American woman, who was 5ft 5in tall and weighed 13-and-a-half-stone, died eight months after stopping the drugs - fenfluramine and phentermine. A post-mortem examination indicated that lesions on her pulmonary arteries had developed as a result of brief exposure to the drugs.
Her case is described in today's New England Journal of Medicine which also carries a report on 24 women who developed a disease of the heart valves after an average 12 months on the same drugs. One of the 24 had taken the drugs for only one month. A third of the women had also developed pulmonary hypertension.
The Journal considered the findings of that study, conducted by a team from the Mayo Clinic in Rochester, Minnesota, to be so serious that they allowed them to be released in advance of publication. A warning based on the findings, issued by the US Food and Drug Administration last month, led to reports of a further 28 cases from across the US, some associated with other appetite suppressants.
An editorial in the Journal says that the cases are "chilling reminders that succumbing to the allure of diet pills as a quick fix for excess weight may be courting disaster." It says they carry a disturbing echo of previous outbreaks of pulmonary hypertension in Europe in the late 1960s and early 1990s, which were also linked with appetite suppressants.
Diet pills have become a national craze in the US, and their use is growing in Britain. More than 18 million prescriptions for fenfluramine combined with phentermine were issued in the US in 1996. The Journal says the use of diet pills for cosmetic reasons should be banned until their risks are better known.
"The only justifiable medical use of anorectic [appetite reducing] drugs is in seriously obese patients who have obesity related illnesses such as heart disease, diabetes and hypertension. For generally healthy people who want to lose a few pounds there are safer alternatives."
A report on obesity by the UK Royal College of Physicians, published in May, concluded that the use of appetite suppressants in the very fat was justified where other methods of weight loss such as diet and exercise had failed.
It said obesity was a serious medical condition with an increased risk of joint disorders, heart disease and diabetes and even a 10 per cent loss of weight could significantly reduce these risks.Reuse content