COMPARATIVE WHEAL AND FLARE STUDY OF MIZOLASTINE VS TERFENADINE, CETIRIZINE, LORATADINE AND PLACEBO IN HEALTHY-VOLUNTEERS

1 Mizolastine, a new benzimidazole derivative with potent selective, n on-sedative H-1-histamine antagonist activity was compared with terfen adine, cetirizine and loratadine using the histamine-induced wheal and flare model in healthy volunteers. 2 Study design was a five way doub le-blind crossover design using a single dose of mizolastine 10 mg, te rfenadine 120 mg, cetirizine 10 mg, loratadine 10 mg and placebo. 3 Hi stamine tests were performed on 10 occasions up to +24 h after dosing using an intradermal injection of histamine 2 mu g with concommittant contralateral injection of a saline control. 4 Mizolastine, terfenadin e, cetirizine and loratadine significantly (P<0.001 vs placebo) inhibi ted the wheal and flare formation starting 1 to 2 h after dosing up to 24 h after dosing. 5 Mizolastine was significantly more active than l oratadine on the wheal (P<0.01) and flare (P<0.05) inhibition from 3 u p to 6 and 8 h respectively, as active as terfenadine on both paramete rs and as active as cetirizine on wheal inhibition while less active ( P<0.01) than cetirizine on hare inhibition at 2 and 12 h post-dosing.