Effects of a sedative and of a non-sedative H1-antihistamine on the event-related potential (ERP) in normal volunteers.

Measurements of the amplitude and latency of the P3b component of the event-related potential (ERP), simple reaction time (SRT) and four psychomotor tests (VAS, DSST, DSp and CFF) were made on 12 male subjects (aged 19-24 years) 1.0-1.5 and 4.0-4.5 h after single oral doses of triprolidine (7.5 mg), terfenadine (60 mg) and placebo. Neither triprolidine nor terfenadine changed P3b amplitude or latency although VAS, CFF and DSST scores were significantly altered by triprolidine at 1.0-1.5 h after dosage. These results suggest that the P3b is too robust to reflect the mild sedative properties of an H1-receptor antihistamine, or that H1-receptors are not involved in P3b generation.