Research Article

Mechanism of action of antipruritic drugs.

Br Med J (Clin Res Ed) 1983; 287 doi: (Published 22 October 1983) Cite this as: Br Med J (Clin Res Ed) 1983;287:1199
  1. L Krause,
  2. S Shuster


    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.