Mechanism of action of antipruritic drugs.
Astemizole and terfenadine, two potent non-sedative H1 antihistamines, had no effect on itch measured objectively as nocturnal scratching and subjectively on a 10 cm line. Trimeprazine, however, a more sedative but less potent H1 antihistamine, was antipruritic, as was nitrazepam, a sedative benzodiazepine. We concluded (a) that antipruritic drugs act centrally by a property related to sedation; (b) H1 receptor antagonists have a peripheral antipruritic action only when itch is due to histamine release, as in the wealing disorders. Thus the new nonsedative H1 antihistamines have no place in the treatment of itch from other causes.
D000293:Adolescent; D000328:Adult; D000368:Aged; D000982:Antipruritics / Q000627:therapeutic use; D016589:Astemizole; D001559:Benzhydryl Compounds / Q000627:therapeutic use*; D001562:Benzimidazoles / Q000627:therapeutic use*; D005260:Female; D006634:Histamine H1 Antagonists / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009567:Nitrazepam / Q000627:therapeutic use; D011537:Pruritus / Q000188:drug therapy*; D016593:Terfenadine; D014291:Trimeprazine / Q000627:therapeutic use
D000982:Antipruritics; D001559:Benzhydryl Compounds; D001562:Benzimidazoles; D006634:Histamine H1 Antagonists; D014291:Trimeprazine; D016593:Terfenadine; D016589:Astemizole; D009567:Nitrazepam