Background:

Rocastine is a selective, nonsedating H1 antagonist, acting as an antihistamine.

Rocastine is effective with a 15 min pretreatment time (PD50 = 0.13 mg/kg) as it is with a 1 hr pretreatment time (PD50 = 0.12 mg/kg). Rocastine protects guinea pigs from collapse induced by aerosolized antigen; rocastine is approximately 36x more potent than diphenhydramine and as potent as oxatomide and terfenadine. Rocastine does not alter the EEG of cats at doses in vast excess (150x) of its antihistaminic dose nor does it potentiate yohimbine toxicity in mice[1].

[1]. Nolan JC, et al. Rocastine (AHR-11325), a rapid acting, nonsedating antihistamine. Agents Actions. 1989 Aug;28(1-2):53-61.