Astemizole-D causes less sleep impairment than loratadine-D

This randomized, double-blind, double-dummy, parallel-group trial was initiated to evaluate and compare the tolerability of once-daily astemizole-D capsules (10 mg astemizole/240 mg pseudoephedrine) and twice-daily loratadine-D tablets (5 mg loratadine/120 mg pseudoephedrine), with particular reference to the impact of treatment on quality of sleep. A total of 240 healthy volunteers participated in this study with a treatment duration of 3 days. Astemizole-D consistently produced less sleep impairment than loratadine-D with statistically significant differences in favour of astemizole-D reported for night-time waking on days 4 and 5 (P = 0.004 and P = 0.006, respectively), as well as for night-time restlessness on day 4 and the total score for all sleep parameters on day 4 (P < 0.05). Global evaluations of overall sleep quality at the end of the trial also revealed some statistically significant differences in favour of astemizole-D. Both drugs were well tolerated and there were no differences in the incidence and type of adverse events reported in the two treatment groups. Slight changes in heart rate and blood-pressure were observed in both treatment groups, but these were small and were not considered to be of clinical significance. In conclusion, once-daily astemizole-D is well tolerated and appears to cause less sleep impairment than twice-daily loratadine-D.