Allergies: the last antihistamines can drive without drowsiness

Only third-generation antihistamines do not exhibit sedative effect and thus allow to drive safely, indicate the results of a synthesis performed by a Dutch team, published in the journal "Annals of Allergy, Asthma and Immunology."

Histamine acts as a chemical mediator in allergic reactions massively released during an allergen contact, it causes vasodilation of blood vessels responsible for the appearance of edema during attacks hives, but the contraction of smooth muscles bronchi causing asthma attacks.

Many affected by allergic disease, some of which are likely to be brought to drive people, so are prescribed antihistamines.

But these drugs can cross the blood-brain barrier, a physiological boundary between the blood and the brain, which protects it from potentially harmful substances. As histamine is involved in the activation of certain neurons belonging to the circuit of awakening, the consumption of antihistamines can cause drowsiness.

Dr. Joris Verster, Institute of Pharmacology, Utrecht (Netherlands), and his colleagues decided to review all the data on this class of drugs obtained through studies "in position" that is to say on the road in normal traffic conditions.

Their analysis shows the first generation antihistamines significantly impair performance on driving, as after a single administration after repeated administration (daily). Driving with such drugs should be considered dangerous, the authors write.

The second-generation antihistamines, usually presented as less sedating, they actually induce less drowsiness, still affect the ability to drive with a variable magnitude and duration by sex, dose, and the time between testing and decision.

However, two third-generation antihistamines may be considered non-sedating and therefore safe for patients who want to drive, conclude the authors of this summary. Dr. Joris Verster and his colleagues did not want, in this analysis, decide on a third representative of this class, for which only laboratory data not involving tests in real conditions were available at the time of writing their article.

One study showed that third antihistamine does not affect the ability to drive a vehicle on the road, and Dr. Joris Vester now considers these three third-generation antihistamines such as non-sedating.