After 2 hours, the reduction in cough frequency achieved with cloperastine was significantly greater than that achieved with clobutinol ( p <0.01); the difference remained significant at 4 hours ( p <0.05) and highly significant at 6 hours ( p <0.001), with significance being lost at 8 hours post-dose both compared to baseline and to clobutinol at the same time point.
42 Cloperastine and codeine also significantly reduced cough intensity, whereas the other agents did not reach statistical significance. 42 Peripheral antihistaminic and spasmolytic effects Quantitatively, the antihistamine potency of cloperastine is estimated to be approximately one-quarter that of diphenhydramine: 24 Gregori-Puigjané et al. 44 reported a K i value of 3.8 nM for cloperastine at the H1 receptor, virtually the same as chlorphenamine, a first-generation H1 antihistamine.
Specifically, the baseline ‘very disturbed’ sleep scores were reduced by 32% (pills, p <0.001 vs baseline) and 23% (chewable tablets, p <0.05 vs baseline) after cloperastine treatment, whilst codeine failed to reach statistical significance in this parameter.