A Double-Blind Trial of Terfenadine and Placebo in Hay Fever Using a Substitution Technique for Non-Responders

Abstract

A double-blind study of terfenadine and placebo in 110 patients suffering from hay fever (confirmed by skin tests) was conducted. A novel technique was applied using an escape envelope containing a reference drug which could be taken under controlled conditions if, after 48 hours, the patient experienced no relief. Significantly more patients on placebo opened the envelope than patients taking the active drug. Terfenadine was demonstrated to be an effective drug in hay fever and produced no more drowsiness than placebo.

Histamine and H1-antihistamines: Celebrating a century of progress

“…Cloning and characterization of human histamine receptors was reported for the H 2 -receptor in 1991, the H 1 -receptor in 1993, the H 3 -receptor in 1999, and the H 4 -receptor in 2000. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] H 1 -antihistamines downregulate allergic inflammation directly through the H 1 -receptor by interfering with histamine action at H 1 -receptors on sensory neurons and small blood vessels. Through the ubiquitous transcription factor nuclear factor-kB, they also decrease antigen presentation, expression of proinflammatory cytokines and cell adhesion molecules, and chemotaxis.…”