An increased risk of heart attacks and strokes has been linked to a slimming pill containing sibutramine, according to reports published in The Times.

Sibutramine is marketed as Reductril and is prescribed for weight loss in patients who are classed obese or overweight. It is classed as a ‘serotonin-noradrenaline re-uptake inhibitor’ (SNRI) which prevents serotonin and noradrenaline from being taken back up into the brain’s nerve cells. In blocking their re-uptake, the Reductril causes the amount of neurotransmitters in the brain to increase, which in turn leads to the patient feeling fuller after a meal and aids in reducing their dietary intake.

Sibutramine was put under the spotlight in 1999 and 2002 by the EMA (European Medicines Agency) when concerns were raised over its cardiovascular side-effects – namely increased hypertension and increased heart rate. At each of these investigations, the CHMP (Committee for Medicinal Products for Human Use) concluded that the benefits of the drug outweighed the risks. However, the CHMP asked Abbott Laboratories, the manufacturers of Reductril, to commence work on a study of patients taking sibutramine with cardiovascular risk factors, concentrating particularly on the medicine’s safety. CHMP requested six-monthly updates on the progress of the report.

Consequently, in 2002, Abbott Laboratories started the SCOUT study (Sibutramine Cardiovascular Outcome Trial). Approximately 9800 patients were studied and compared patients taking sibutramine with those taking a placebo. Factors measured included weight loss and the occurrence of cardiovascular events such as heart attack, stroke and cardiac arrest.

The full data has not yet been completely analysed but there are strong indications that sibutramine is associated with more cardiovascular problems than a placebo.

As a result, the CHMP has concluded that the benefits of taking sibutramine as a weight loss drug do not outweigh the risks and has recommended that the drug is suspended across the European Union. Doctors and other medical practitioners have been advised to cease prescribing the drug to their patients. This suspension will remain until the company can prove that taking sibutramine is safe to do so and that the risks are minor in comparison to the benefits.

Anyone currently taking Reductril is advised to make a routine appointment with their GP. It is also safe to stop treatment at any time as there are no health implications from doing so.