Quinotolast sodium inhibits histamine, LTC4 and PGD2 release in a concentration-dependent manner in the concentration range of 1-100 μg/mL.

Quinotolast significantly inhibits PGD2 and LTC4 release. Quinotolast inhibits PGD2 release by 100% and LTC4 release by 54%. The inhibitory effect of Quinotolast on histamine release from dispersed lung cells is largely independent of the preincubation period, no tachyphylaxis being observed. Quinotolast shows a significant inhibition of inflammatory mediators from human dispersed lung cells[1].

Quinotolast is given i.v. to rats, Quinotolast, dose-dependently inhibits PCA. The doses of Quinotolast required to inhibit the reaction by 50% (ED50) is 0.0063 mg/kg. Given p.o.[2].Quinotolast potently inhibits such type I allergic reactions as passive cutaneous anaphylaxis (PCA) and anaphylactic bronchoconstriction in rats by both intravenous and oral dosing.