Are anti-obesity drugs worth the risk?

The medical journal The Lancet has raised questions about the safety and effectiveness of anti-obesity drugs.

A commentary in the journal says long-term safety and efficacy need to be documented for Xenical (alos known as orlistat, its generic name), Meridia (sibutramine) and Acomplia (rimonabant) before doctors can be certain that the benefits of these anti-obesity drugs outweigh the risks.

Acomplia is already under review by the US Food and Drug Administration.

The drugs reduce weight by a few kilograms but the authors of the commentary, Dr. Raj S. Padwal and Dr. Sumit R. Majumdar, from the University of Alberta Hospital in Edmonton, Canada, say they all have potentially 'important adverse effects' — in other words, risky side effects.

Treatment with orlistat is associated with 'frequent gastrointestinal side effects' (stomach problems), sibutramine may 'raise blood pressure and heart rate', and rimonabant may 'increase the risk of mood disorders' (depression).

These adverse effects are often clear eevn in the short-term but it is the long-term effects that concern the commentators. Padwal and Majumdar say that research on anti-obesity agents is plagued by high drop-out rates and by a lack of data on long-term illnesses and deaths.

They say that long-term detailed data should be required either before these drugs are approved for widespread use or as a condition of ongoing approval.