Inhibitory activity of terfenadine on histamine-induced skin wheals in man.
The inhibitory effect of orally administered terfenadine on the area of histamine-induced skin wheals was studied by single dose and multiple dose trials in 12 normal male volunteers. Single doses of 20, 60 and 200 mg of terfenadine produced dose-dependent decreases in histamine wheal area that reached a maximum by the fourth hour after dosing. The 60 and 200 mg doses blocked almost 90% of histamine whealing, and significant reduction of the wheal area persisted for 8 h. During the multiple dose trial histamine whealing was markedly inhibited after the fifth and sixth dose of terfenadine 20, 40 or 60 mg every 8 h and of 60 mg every 12 h. On the last three dosage schedules inhibition persisted for at least 12 h after the final dose. Inhibition of histamine-induced skin whealing appears to be a quantitative index of the time course of histamine H1-receptor antagonist action.
D000284:Administration, Oral; D000328:Adult; D001559:Benzhydryl Compounds / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006634:Histamine H1 Antagonists; D006801:Humans; D008297:Male; D010880:Piperidines / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D012882:Skin Tests; D013997:Time Factors
D001559:Benzhydryl Compounds; D006634:Histamine H1 Antagonists; D010880:Piperidines