Nearly 1 million patients are every year given the wrong medication by the UK's National Health Service (NHS). Mistakes that get reported have doubled in the last two years.
Every month more than 200 patients require further treatment - or die - because of mistakes over medication, reports the National Patient Safety Agency.
Mistakes included the wrong dose or inappropriate drug being prescribed, and giving a drug to the wrong patient with the same name. It's not just patients who are being mixed up; doctors, too, are sometimes confused about drugs, especially if they have a similar name.
The total number of errors reported in 2007 was 86,085, but the Agency says that the real figure is 10 times worse as few errors are ever recorded.
* Those of you worried about the safety of drugs will be relieved to hear of an important breakthrough in drug monitoring - they're now going to be tested first on insects.
Moths and fruit flies are being lined up to test anti-microbial drugs among others, according to Dr Kevin Kavanagh from the National University in Ireland.
He says that using insects will mean that fewer laboratory mice will be used. The trouble is that tests on mice were never very helpful - so don't hold your breath for the insect data.
(Source: Meeting of the Society for General Microbiology, Edinburgh).