June 13, 2019

Drugs and Driving – Focus on Hay Fever

Is Your Hay Fever Medication Affecting Your Driving?

We all know that drugs and driving just don’t mix, and a new study conducted by insurance comparison site Confused.com highlights the fact.

However, and very worryingly, the study shows that a substantial number of people are driving while under the influence of prescribed and over-the-counter medication, without being aware of the risks they are taking. A particular culprit at this time of year appears to be hay fever medication and, as summer moves on and the pollen count rises, many drivers could be breaking the law without knowing it.

Apart from driving under the influence of any impairing drug obviously being dangerous and illegal for all drivers, the hay fever season could have a significant impact on companies with delivery drivers or mobile sales teams.


The information is based on a One Poll online survey of 2000 UK drivers, conducted for Confused.com between May 1st and May 3rd 2019 and is stated to be a nationally representative sample. The figures in brackets below show the numbers involved which are extrapolated from the sample percentages.

  • There are over 40.5 million currently registered driving licences in the UK (latest figure available is from November 2018).
  • According to the survey, 35% of drivers (14.2 million) are hay fever sufferers.
  • Of these, 73% (10.4 million) have taken hay fever medication before driving.
  • 17% of those drivers (1.8 million) have experienced some type of side effect from the meds. These side effects included blurred vision (reported by 4%), drowsiness (reported by 11%) and slower reaction times (reported by 8%).

girl with hay fever

Driving under the influence

For the medicinal drugs, the legal limits are higher than normal prescribed doses so you’ll be able to drive as normal, as long as:

  • you’re taking the medication in accordance with the advice of a healthcare professional and/or as printed in the accompanying leaflet, and
  • your driving isn’t impaired.

You’ll have a medical defence if you’ve been taking the drugs as directed and are found to be over the limit, but your driving isn’t impaired.

It’s illegal to drive if:

  • you’re unfit to do so because you’re on legal or illegal drugs
  • you have certain levels of illegal drugs in your blood (even if they haven’t affected your driving)

National figures, obtained from a Freedom of Information request made to 27 UK police constabularies in the same study, showed that the numbers of drivers caught driving while under the influence (DUI) of some type of drug is increasing. The figures include the use of legal and illegal drugs.

Essex is shown to have the highest English incidence, with 984 drivers caught DUI in 2018/19. Scotland has the highest UK figures, with 5847 reports in 2018/19.

Safe medications?

Many over-the-counter hay fever medicines contain antihistamines like hydroxyzine, promethazine and chlorphenamine. Some antihistamines are safe to take while driving and some can cause inhibiting side effects. The big problem is knowing which is which.

Staggeringly, the One Poll survey showed that almost one motorist in six – that’s 16% – has no idea which antihistamines they can take for their hay fever and then safely get behind the wheel.

Of the 2000 motorists surveyed, 47% felt that doctors and pharmacists should make a point of giving clearer advice on the safety of prescription drugs when driving.

Almost half at 48% also thought that medication packaging should have clearer warnings and more instructions regarding the potential effects of the drug on driving ability. This, despite the fact that most over-the-counter medications now come with a leaflet which explains in great detail what to expect when taking the medicine.

However, do be aware that the onus is on you to find out what the side effects of your medication may be when you buy from the chemist. You can ask for detailed information from the pharmacist if you’re not sure. They may warn you anyway if the drug causes side effects which can make driving unsafe, but make sure you ask anyway.

Your doctor should also give you that information as a matter of course when you get the prescription but, again, don’t assume so. Always double check to cover yourself.


In the survey, 5% of drivers said they have felt incapable of safely driving after taking either a prescribed or over-the-counter remedy. If they had continued to drive in that condition and had been caught, they’d have faced a minimum charge of careless driving. This carries a fine of £5000, plus between 3 and 9 points on the driving licence, with the possibility of disqualification.


Clearly, as a company which runs fleet vehicles and has employees driving on business, it is extremely important to ensure that staff are made aware of the possible risks of using hay fever and other meds while driving. It’s worth emphasising the point regularly through the summer months particularly, with regular reminders in training, briefing and even emails and other communications – and of course including this in your fleet policy.

For more information on company driving while on medication, read our other post on the subject.

Search tool

Confused.com has compiled a simple search tool to help you decide if your medication is safe to take while driving.