S-555739 + cetirizine

**S-555739 + cetirizine** is a combination of two small-molecule drugs: asapiprant (S-555739), a selective antagonist of the prostaglandin D2 receptor 1 (DP1 receptor), and cetirizine, a second-generation antihistamine that acts as a selective histamine H1 receptor antagonist. Asapiprant inhibits the effects of prostaglandin D2 on the DP1 receptor, leading to reduced inflammation and nasal airway resistance, while cetirizine blocks histamine-induced allergic symptoms by competitively inhibiting the H1 receptor. This combination targets both prostaglandin-mediated and histamine-mediated pathways implicated in allergic diseases such as rhinitis. Asapiprant was developed by Shionogi and is being studied for allergic rhinitis and related airway inflammatory conditions, with cetirizine widely approved and marketed for allergic conditions.

Other names

asapiprant + cetirizine