Placebo controlled comparison of acute effects of ebastine and clemastine on performance and EEG

Abstract

The effects of single oral doses of 10 and 20 mg ebastine were compared with placebo and 2 mg clemastine in a double-blind cross-over study in 16 healthy male volunteers. Clemastine produced the known pattern of changes, namely impairment of psychomotor performance, drowsiness, and a selective effect on cognitive processes. Earlier encoding in a perceptual stage was slowed whereas abstract classification processes were not affected. Electrophysiological measures of vigilance showed a general decrease in vigilance especially 2.5 and 4.5 h after dosing. In contrast at no time was any effect of ebastine different from that of the placebo. Ebastine 10 and 20 mg differed positively from clemastine in its effect on pursuit tracking, subjective rating of drowsiness and general discomfort. Ebastine 10 mg also differed positively from clemastine in the EEG features of vigilance. It is concluded that 10 and 20 mg ebastine were free from sedative adverse effects.

Ebastine in allergic rhinitis and chronic idiopathic urticaria

“…In trials including a positive control as well as a placebo group, the effects of ebastine 10 and 20 mg were similar to those of placebo, whereas, as expected, the positive controls (clemastine 2 mg and sustained-release triprolidine 10 mg) were associated with significant impairment of cognitive and psychomotor function (82)(83)(84). Clemastine impaired visual-motor coordination, decreased vigilance and increased subjective drowsiness in healthy volunteers (82).…”

“…The effects of ebastine were generally similar to those of placebo in tests of vigilance, cognitive performance, visual motor coordination, subjective estimates of drowsiness and driving performance (37,(81)(82)(83)(84). In one study, ebastine 10 mg caused a marginally significant increase in choice reaction time compared with placebo at 8 h after a single dose (95% CI for the difference 0.01-0.23), and a dose of 50 mg (2.5 times the maximum recommended dose) caused an increase in this parameter at 4 and 8 h (95% CI for the difference at both timepoints 0.01-0.25) as well as modest increases in indices of sedation (P < 0.05 vs placebo) (81).…”

“…Compared with clemastine, ebastine 20 mg caused significantly less drowsiness and less general discomfort, and both ebastine 10 and 20 mg caused significantly less impairment in pursuit tracking at 2.5 and 4.5 h after dosing. Ebastine 10 mg caused significantly less impairment of vigilance than clemastine at 2.5 and 4.5 h, as assessed by EEG (82).…”

“…Clemastine impaired visual-motor coordination, decreased vigilance and increased subjective drowsiness in healthy volunteers (82). Compared with clemastine, ebastine 20 mg caused significantly less drowsiness and less general discomfort, and both ebastine 10 and 20 mg caused significantly less impairment in pursuit tracking at 2.5 and 4.5 h after dosing.…”

The Prevalence, Morbidities, and Treatments of Insomnia

“…Performance decrements with diphenhydramine generally accompany subjective ratings of drowsiness [53, 55-61, 63, 65, 68], although the relationship between these variables is complex and does not always track pharmacokinetic parameters (see below). Decreases in daytime functioning or increases in subjective sleepiness have been shown for clemastine [69,70] chlorpheniramine (racemate and dex-) [61,[71][72][73][74], Rdimethindene [71] dimenhydrinate [75,76], promethazine [77], hydroxyzine [52,[78][79][80][81], ketotifen [53,82], and triprolidine [71,83]. Thus, antihistamine-induced drowsiness is common across a broad class of compounds with varying pharmacological profiles.…”