GPs 'making too many drug errors' in England
2 May 2012 Last updated at 07:33 BST
About one in six patients are being given inaccurate prescriptions by GPs in England.
Researchers found incorrect instructions and dosage information, as well as failures to monitor the effects of drugs on patients.
The Royal College of GPs says prescribing standards are high, but accepts that some doctors would benefit from more training on computer systems.
The BBC's Jane Dreaper reports.