Could driving on hayfever medication be dangerous?

Sufferers who get behind the wheel may be risking life and limb, or a driving ban, says

The number of us suffering from allergic rhinitis – commonly known as hayfever – has rocketed over the past few years. Research by Allergy UK says nearly half of the UK’s population (49 per cent) now has some form of hayfever. And it claims a quarter (26 per cent) of UK adults regularly suffer from the condition. One way round it for many of us is over-the-counter medicine. But might your go-to product make you as dangerous as a drunk driver? We investigate.

Why does hayfever medication make you drowsy?

Hayfever is when our body reacts to pollen from flowers, trees and grasses as if it’s harmful. To protect itself, the body produces histamines, chemicals designed to remove anything the body thinks is attacking it. The result is streaming and itching eyes, running noses plus coughing and sneezing: all symptoms of hayfever. Antihistamine medication stops histamine production to alleviate hayfever symptoms. But there are two antihistamine types: first generation – the drowsy ones – and non-drowsy second generation.

Hay fever cures to use – and some not to choose

First-generation cures for drivers to avoid include chlorphenamine (found in Piriton, Hayleve and Boots Allergy Relieve), hydroxyzine (Atarax) and promethazine (Avomine or Sominex).

Second-generation antihistamines don’t cross the blood-brain barrier so are less likely to make you sleepy if you take them in the correct quantities. The main types are cetirizine (usually branded Piriteze), loratadine (branded Clarityn) and Acrivastine in Benadryl Allergy Relief. But drugs have different effects on different people. And the NHS warned: “Fexofenadine (in Allevia and Telfast) is classed as a non-drowsy antihistamine, but some people still find it makes them feel sleepy.”

Why is hayfever and driving such a problem?

Road safety charity Brake says driving while drowsy can be as dangerous as drink-driving. Sneezing while driving is perilous, too. When we sneeze, our eyes are forced shut. Assuming a sneeze takes one second, at 30mph we’ll travel 45ft (13.7m) with our eyes closed. At 70mph, we’ll travel 105 feet (32m). That’s around seven car lengths, effectively driving blind.

How many crashes have drivers on hayfever medication had?

Currently there are no statistics around the number of collisions involving drivers made drowsy by hayfever medication. Establishing this would involve police crossreferencing all accident victims with their medical records, which doesn’t happen. But Dr Ashleigh Filtness, professor of human transport factors at Loughborough University, told us: “We believe about 20 per cent of collisions are caused by drowsy drivers.

What’s the worst that could happen?

It’s against the law to drive with legal drugs in your system if it impairs your driving. If you get caught, you could face a minimum one-year ban, an unlimited fine, up to six months in prison and a criminal record. The maximum penalty for causing death by dangerous driving while under the influence of drugs is life in prison.

The conviction will stay on your driving licence for 11 years, meaning the lengthy hangover of more expensive insurance.

What can you do about it?

First, recognise if you’re feeling drowsy. Dr Filtness advised: “If you’re having to open the window or turn the radio up while driving because you know you’re tired, you should get off the road. You can’t overcome sleepiness.

“A lot of hayfever medication is taken once a day. For most people, I’d suggest they take it when they get home in the evening so the body has plenty of time to process it before they drive again.”

When you’re not driving, turn your car’s ventilation fan up to maximum and give the vents a good blast to dislodge dust in them. Then vacuum the seats, mats and carpets to get rid of any pollen lurking in the car.

Charity IAM Roadsmart’s head of driving and riding standards, Richard Ladyman, said: “Keeping your windows closed and setting your air-con to recycle will help. Put a few dabs of Vaseline inside your nostrils to help catch pollen. Keep tissues to hand in the car. And if you do think you’re going to sneeze, slow down or drop back from the vehicle in front.”