Canadian researchers at Lakehead University and Northern Ontario School of Medicine in Canada have found that taking the morphine-like painkiller codeine before driving may be linked to an increase in fatal road accidents.

The Daily Mail reports that the team analysed incidences of fatal road accidents in the US from 1975 onwards and discovered that more than 2,100 drivers who died had taken codeine, morphine or methadone – a class of painkiller known as opiates.

When these deaths were matched to accident reports, the researchers found that drivers with the drugs in their system were more likely to have been going too fast, driving dangerously or recklessly – or veering across the road. Overall, men were 74 per cent more likely to have exhibited risky driving behaviour if they had taken one of the painkillers before getting behind the wheel of their car.

Female drivers killed in road accidents were found to be 42 per cent more likely to have committed an ‘unsafe driving action’ if they had taken the painkillers.

The team found that young or middle aged drivers were also more likely to be affected by using painkillers while driving.

The researchers said:

'Failure to keep in the proper lane was the number one fault – but approximately 18 per cent of "positive" drivers were driving too fast, 7 per cent made improper turns and 6 per cent drove recklessly.’

The researchers added that the increased risk might possibly have been ‘due to an underlying medical condition’.

The UK government issued a warning this year, advising that painkillers such as codeine should not be taken for more than three consecutive days because of the risk of addiction.

Codeine is a prescription-only drug if used on its own – but it is included in popular over-the-counter medicines such as Solpadeine and Nurofen Plus in varying doses.

The Canadian team found that the drug can make some drivers feel sleepy, making them react more slowly to traffic events and therefore more likely to make a mistake.

In the UK, around 27 million packets of painkillers containing codeine are sold over-the-counter each year.

Sheila Kelly of the Proprietary Association of Great Britain – an organisation that represents
pharmaceutical manufacturers – said that a government review had concluded that warning labels about drowsiness were not necessary on medicines containing low doses of codeine.

However, she advised consumers to read the label on any product they bought over-the counter – and to be aware of which medications could cause drowsiness.

The findings of the Canadian study are published in the journal Accident Analysis and Prevention.

© 5r1 Limited 2010