A Department for Transport study, undertaken by Loughborough University's Sleep Research Unit, found the recommended range of advisory labels on medicines warning of possible drowsiness are not always followed closely by manufacturers. Ensuring drivers understand the dangers of certain medicines is vital, as research suggests fatigue may be responsible for up to one in 10 accidents on motorways and up to one in 20 on other roads.
Furthermore, it is an offence to drive when unfit through drink or drugs and the law makes no distinction between impairment due to illegal drugs and impairment due to medicinal drugs.
The penalties are the same as for drinking and driving – disqualification for at least a year, a fine of up to £5,000 and up to six months' imprisonment.
The research discovered that the accuracy of information regarding drowsiness provided by manufacturers is inconsistent. Medicines containing the same active ingredient at similar doses ought to have the same advice regarding their potential to produce drowsiness, but this is not always the case.
The report's authors also warn that label visibility is often inadequate and most require improvements.
Road safety minister David Jamieson said: 'There are more than one hundred over-the-counter medicines with a potential to cause drowsiness. To ensure that motorists drive safely, it is vital that they are warned about the dangers of drowsiness. Labelling must be clear and understandable to people and I understand that the Department of Health and the Medicines and Healthcare Products Regulatory Agency (MHRA) are examining the issue.
'Particularly in the hayfever season, people should check with their pharmacist if they are in doubt and pull over if they feel drowsy while driving.'