Millions of motorists use medicines which could impair their driving, according to the RAC Foundation.

As the hay-fever season begins, most drivers are unaware that over-the-counter and prescription medicines can affect their concentration and reaction speeds.

Medicines which can affect driving include decongestants and antihistamines (taken for hay fever) which can cause sleepiness and delayed reaction times.

In fact, the recommended dose of some can have a worse effect on driving than being over the alcohol limit.

Other medicines can cause blurred vision and loss of concentration.

The RAC Foundation advises motorists to remember the three Rs: Read the small print; stick to the Recommended dose and Ring your pharmacist or doctor for advice if you feel your driving has been affected.

If in doubt, stop driving don't stop taking the medicine.

Ask the pharmacist for a safe alternative.