triprolidine and mequitazine

Effects of H1 (mepyramine, mequitazine, triprolidine and brompheniramine) and H2 (cimetidine and ranitidine) antagonists on sleep were studied in healthy man. There were no effects of mepyramine (50 and 100 mg), and the only effect of mequitazine (5 and 10 mg) was a reduction in the number of awakenings. Triprolidine (10 and 20 mg) and brompheniramine (4 and 8 mg) did not alter wakefulness during sleep or the total sleep time, but rapid eye movement sleep was reduced. There were no effects of ranitidine (150 and 300 mg), but slow wave sleep was increased by cimetidine (200 and 400 mg). It is tentatively suggested that the histaminergic system is concerned with the mechanisms which favour vigilance during the wakeful state, and the balance between wakefulness and slow wave activity during sleep. Effects of some H1 antihistamines on rapid eye movement sleep are believed to be due to their monoaminergic rather than their histaminergic activity.

Topics: Adolescent; Adult; Brompheniramine; Cimetidine; Electroencephalography; Histamine H1 Antagonists; Histamine H2 Antagonists; Humans; Male; Phenothiazines; Psychomotor Performance; Pyrilamine; Ranitidine; Sleep; Sleep Stages; Sleep, REM; Triprolidine

The effects of single oral doses of mequitazine (5 and 10 mg), terfenadine (60 mg) and triprolidine (10 mg) as active controls, and placebo were evaluated on visuo-motor coordination, digit symbol substitution, critical flicker fusion and dynamic visual acuity, and on subjective assessments of mood and well-being in six normal female volunteers. The study was double-blind. Mequitazine (5 mg) impaired visuo-motor coordination 7.5 h after ingestion (considered to be a chance result), but there was no effect on digit symbol substitution, critical flicker fusion threshold or dynamic visual acuity. Mequitazine (10 mg) impaired visuo-motor coordination and reduced the number of substitutions on the digit symbol substitution test. Terfenadine (60 mg) had no effect on performance or on subjective feelings. Triprolidine (10 mg) impaired visuo-motor coordination, reduced the number of substitutions on the digit symbol test, lowered the critical flicker fusion threshold and reduced dynamic visual acuity. Mequitazine (5 mg) and terfenadine (60 mg) are likely to prove acceptable H1 antagonists when sedation must be avoided.

Topics: Adult; Benzhydryl Compounds; Double-Blind Method; Female; Flicker Fusion; Humans; Phenothiazines; Psychomotor Performance; Terfenadine; Triprolidine; Visual Acuity