Wiktionary
n. A particular antihistamine used to treat allergy and hay fever.
Wikipedia
Acrivastine is a medication used for the treatment of allergies and hay fever. It is a second-generation H1-receptor antagonist antihistamine (like its base molecule triprolidine) and works by blocking histamine H1 receptors.
This non-sedating antihistamine is sold under the brand name Benadryl Allergy Relief in the United Kingdom by McNeil Laboratories. It should not be confused with Benadryl Once a Day which has cetirizine as the active ingredient and is also sold by McNeil in the UK. It is available as an over-the-counter medicine in the UK, and is available with or without pseudoephedrine under the Benadryl brand.
In the U.S., acrivastine is the active ingredient in the Semprex brand. Semprex-D also contains the decongestant pseudoephedrine. Semprex-D is marketed in the U.S. by Actient Pharmaceuticals.