Patients' lives are being put at risk because of serious flaws in the yellow card scheme used to gather reports from doctors on the side effects of drugs, it was claimed yesterday.

The body that licenses new drugs, the Medicines Control Agency, asks doctors to fill in the yellow card to report patients' serious side effects while on medication. If the drug is less than two years old, doctors must report all side effects.

The MCA asks pharmaceutical firms - which send doctors information sheets on their products listing likely side effects - to designate all new drugs with a black triangle.

But the Drug and Therapeutics Bulletin, an influential journal sent to all doctors and published by the Consumers' Association, found that 25% of these information sheets did not carry the triangle mark - an omission that could lead doctors to ignore any side effects not appearing serious.

The bulletin also found the drugs information sheets' data on side effects was often inconsistent and unhelpful. Of 25 data sheets on as many new, black triangle-listed medicines known to have potentially damaging effects on the liver, 14 gave no details on the type of liver impairment possible.

Most of the sheets gave the doctors little or no suggestion as to advice for the patient.

Joe Collier, professor of medicines policy at St George's hospital school of medicine in south London and editor of the bulletin, said the issue should be taken very seriously by the regulatory authorities.