Most adverse reactions to drugs are not reported

At least three out of four suspected adverse reactions to drugs are going unreported by doctors because they are too busy, unclear how the system works, or unsure what constitutes a serious reaction, a government watchdog says today.

The system for controlling medicines in the UK is, in general, safe but health professionals are not sending enough information in and warnings about drugs are not getting through to the public, the National Audit Office says.

Twelve drugs have been withdrawn from the market in the past five years because of safety fears that have arisen after they were licensed, but 200 new drugs have been launched in the same period.

In at least one case, a drug was withdrawn after repeated warnings failed to alter prescribing practice. The drug, Cisapride, a treatment for heartburn, provoked irregular heartbeat in some patients when prescribed with certain other drugs. Despite a series of alerts issued between 1995 and 1999, prescribing Cisapride with potentially interacting medicines remained virtually unchanged and the Committee on Safety of Medicines decided in 2000 that the risks outweighed the benefits and it should be banned.

Faulty labelling contributed to the deaths of 13 patients over 15 years who were wrongly given a cancer drug, vincristine, into the spine when it should have been given into a vein. The drug had been labelled "not for intrathecal use" but after the death of the latest victim, an 18-year-old man in Nottingham in February 2001, the committee ruled labels should state "for intravenous use only". The Department of Health has now asked manufacturers to design devices that would prevent the administration of the wrong drug into the spine.

In a report published yesterday, the NAO commends the Medicines Control Agency (MCA) for its world class system for protecting public health but says more must be done to raise its public profile and ensure its messages are heard. It says most leaflets enclosed with medicines are unhelpful and confusing for patients and better labelling would reduce "medication error" in hospitals.

In contrast to the US Food and Drug Administration, which has a high public profile and issues information directly to consumers, the MCA is "not well understood by the wider public and even many health professionals". The MCA is expected to merge with the Medical Devices Agency in April.