A GROUP of slimming drugs should be used only for obese people who cannot lose weight through diet and exercise, doctors were told yesterday.
In the first report on the safe use of slimming drugs including the appetite suppressants fenfluramine and dexfenfluramine, the Royal College of Physicians recommended new guidelines for GPs and doctors in private slimming clinics.
The college said that other medication including addictive amphetamines, diuretics, which reduce the body's water content, and thyroid hormones to speed up the metabolism should not be used as aids to weight loss.
A third appetite suppressant drug, phentermine, could be prescribed but was licensed for use only over 12 weeks.
Two years ago Tom Sackville, then a junior minister, said slimming drugs should be banned because of fears of side-effects and reports that slimming clinics were readily prescribing the drugs to women who were not overweight but merely wanted to be thinner.
The Department of Health asked the college to report on the use of slimming drugs.
Dr Peter Kopelman, who chaired the RCP working party, said yesterday that the benefits for weight loss in obese people outweighed the "very small" risks of the drugs, which have been available for 30 years.
The report said that in rare cases the drugs could produce a serious side-effect, giving rise to high blood pressure in the lungs and heart. The insidious onset of this condition might be difficult to detect.
It recommended that fenfluramine and dexfenfluramine should only be prescribed after three months, when dieting and exercise regimes had failed, and patients should be carefully monitored.
The drugs should not be used for more than 12 months because long-term effects were not known. If a weight loss of 10 per cent had not been achieved after three months they should be discontinued.
Dr David London, registrar of the RCP, said that the General Medical Council was interested in the findings. It was hoped that the recommendations would be included in the GMC's current review of professional standards.
The RCP report also said that private doctors who prescribed the drugs had to tell patients' GPs in writing, to avoid interactions with other drugs.
"We do not know the size of the problem of inappropriate use of the drugs in private clinics but we would fervently discourage their use in people who are not overweight," said Dr London.
The report Overweight and Obese Patients said the incidence of obesity in England had doubled between 1980 and 1994, increasing in men from six per cent of the population to 13.8 per cent and in women from eight per cent to 17.3 per cent.
A simple definition of being overweight was a waist measurement of 35 inches in a man and 32 inches in a woman and for obesity, 40 inches in a man and 37 inches in a woman.
A spokesman for the GMC said yesterday that it had issued guidance in 1993 on prescribing slimming drugs and advised patients to consult their GPs about weight problems before going to private practitioners.
Irresponsible prescribing was seen as serious professional misconduct, he added. "But the GMC can't take any action unless we receive a complaint about a specific practitioner who would have to be seen to be prescribing irresponsibly."
GMC guidance was that the main treatment for obesity was an appropriate diet.
