Popular weight-loss drugs are not very effective and are linked to a range of unpleasant and dangerous side-effects, experts
claimed yesterday. Anti-obesity drugs include orlistat,
sibutramine and rimonabant. Over a year, they reduce weight by an average of 5kg (11 pounds) at the most, say Dr Raj Padwal of the
University of Alberta, Canada, and colleagues. Their study
combined evidence from 30 adult trials. Participants began with an average weight of 100kg (15.7 stone) and body mass index of 35-36. Those on orlistat lost 2.9kg, sibutramine lost 4.2kg and rimonabant lost 4.7kg. On bmj.com today (November 16), the authors say this equates to less than five per cent of total body weight. However, all the drugs lowered cholesterol levels, and orlistat may cut the rate of diabetes. Side-effects included depression and anxiety, and 30-40 per cent of patients decided to come off the drugs. In an editorial, Professor Gareth Williams of Bristol University, UK, warns of the dangers of these drugs being sold without prescription, as already happens in the US. This ‘will perpetuate the myth that obesity can be fixed simply by popping a pill and could further undermine the efforts to promote healthy living, which is the only long term escape from obesity’, he writes. Furthermore, Professor Arne Astrup of the University of Copenhagen, Denmark, and colleagues found ‘severe adverse psychiatric events’ among patients on rimonabant. In the Lancet, they report on their analysis of four trials with 4,105 patients.
Patients on 20mg of rimonabant per day were twice as likely to stop due to depression than those on placebo, and three times more likely to stop due to anxiety. Experts from the University of New South Wales, Australia, say this ‘raises major questions about the safety of rimonabant in obese people, who are already at increased risk of depression’. Rucker, D. et al. Long term
pharmacotherapy for obesity and overweight: updated
meta-analysis. Published on bmj.com November 16, 2007. Williams, G. Orlistat over the counter. Published on bmj.com November 16,
2007. Christensen, R. et al. Efficacy and safety of the
weight-loss drug rimonabant: a meta-analysis of randomised
trials. The Lancet Vol. 370, November 17, 2007, pp. 1706-13.
Mitchell, P. B. and Morris, M. J. Depression and anxiety with rimonabant. The Lancet Vol. 370, November 17, 2007, pp. 1671-72.
Fonte: NURSING NEWS