Azelastine is more potent than olopatadine n inhibiting interleukin-6 and tryptase release from human umbilical cord blood-derived cultured mast cells.

Background: Mast cells are involved in early- and late-phase reactions by releasing vasoactive molecules, proteases, and cytokines. Certain histamine-1 receptor antagonists and other antiallergic drugs seem to inhibit the release of mediators from rat and human mast cells.

Objective: Azelastine and olopatadine are antiallergic agents present in the ophthalmic solutions azelastine hydrochloride (Optivar, Asta Medica/Muro Pharmaceuticals, Tewksbury, MA), and olopatadine hydrochloride (Patanol, Alcon Laboratories, Fort Worth, TX), respectively.

Azelastine's inhibition of histamine and tryptase release from human umbilical cord blood-derived cultured mast cells as well as rat skin mast cell-induced vascular permeability: comparison with olopatadine.

Mast cells are involved in early and late-phase reactions by releasing vasoactive molecules, proteases, and cytokines. Azelastine and olopatadine are histamine 1 receptor (H-1R) antagonists with antiallergic effects present in the ophthalmic solutions Optivar and Patanol, respectively. Because it is difficult to obtain animal or human conjunctival tissue, we first investigated the effect of these compounds on histamine and tryptase release from cultured human mast cells (CHMCs) grown out of human umbilical cord blood-derived CD34+ cells.