French researchers have uncovered massive under reporting of adverse reactions to prescription drugs. This means drugs are probably far more dangerous than even the severest of critics realise.

It's been reckoned that only one out of every 24,433 adverse reactions is reported by doctors to the various drug monitoring agencies.

This under reporting was revealed in a study among 100 general practitioners in France's Bordeaux region. The doctors were asked to record any reaction they believed was associated with a prescribed drug. Their responses were then compared to reports received at the Bordeaux drug monitoring centre from doctors not participating in the study.

Doctors in the study reported nearly two suspected adverse reactions a day. This response level was compared with that at the monitoring centre, and researchers were able to work out the general under reporting that takes place across the country.

Dr Alan Gaby, writing in the Townsend Letter for Doctors and Patients, pointed out that the finding underscores the fact that most drugs are poisons which happen to have a few beneficial side effects. "Many prescription drugs are more dangerous than they appear because doctors rarely report side effects to the appropriate authorities," he says (Br J Clin Pharmacol 1997; 43: 177-181).