By Richard Woodman

LONDON, Feb 19 (Reuters Health) - Most patients prescribed the obesity drug Xenical (orlistat) fail to lose enough weight to qualify for continued therapy in Britain, according to findings presented on Tuesday.

Xenical was recommended last year by cost-effectiveness watchdog the National Institute for Clinical Excellence (NICE), but only under strict conditions. Patients must lose 2.5 kilograms (5.5 pounds) by dieting in the month before starting therapy. And those who qualify for therapy must also lose 5% of their weight within three months if they want drug therapy to continue.

The latest findings, presented at a conference in London organised by the Association for the Study of Obesity, show how difficult it can be to meet these conditions in practice.

Dr. Karen Slevin, senior dietitian at University Hospital Aintree, in Liverpool, said an audit had looked at 331 patients with an average weight of 126 kilograms (278 pounds) seen at a specialist weight management clinic. A third were prescribed Xenical.

The data showed that 34% of those receiving Xenical had lost more than 5% of their weight after three months and that a further 20% had lost between 3% and 5%. Approximately 25% had lost less than 3% and about 20% had failed to lose weight or had actually put on weight.

Slevin told Reuters Health that that the results were good, given the high starting weight of many patients. It would be a medical decision whether to observe the NICE guidance and stop therapy in those who failed to lose 5% of their weight after three months.

She added: "If you look at absolute weight loss, rather than percentages, (the results) are very encouraging. Within the group that lost 3% to 5% of their weight, there are people who have lost close to a stone (6.4 kilograms, or 14 pounds)."

Although millions of adults in England and Wales are overweight or obese, NICE estimates that Xenical should only be prescribed to just over 20,000 patients at any one time. It estimates that the drug should cost the National Health Service only about £12 million in the first year.

http://www.reutershealth.com/archiv...219elin024.html