Acrivastine

Acrivastine is a medication used for the treatment of allergies and hay fever. It is a second-generation H1-receptor antagonist antihistamine and works by blocking H1 histamine receptors.

It is sold under the brand name Benadryl Allergy Relief in the U.K. by Pfizer, not to be confused with Benadryl Once a Day, which is cetirizine and is also sold by Pfizer in the U.K. The packaging for each is clearly distinctive.