What is "pirquinozol"

n. A drug investigated as an antiallergen and antiasthmatic agent in the early 1980s but never marketed.

Pirquinozol (SQ-13,847) is a drug which was investigated as an anti allergen and anti asthmatic agent in the early 1980s but was never marketed. Notably, pirquinozol is not an antihistamine, though it does block the release of histamine evoked by allergens, and it does not bind to β-adrenergic receptors either.