“…Therefore, the antagonism of histamine-induced responses by diphenhydramine as the histamine H ,-receptor antagonist was determined within this definite period. Unlike diphenhydramine, metiamide, the highly specific histamine H 2-receptor antagonist (Black, Duncan, Emmett, Ganellin, Hesselbo, Parsons & Wyllie, 1973), has no local anaesthetic action (Hind & Sutton, 1977).…”