Terfenadine and placebo compared in the treatment of chronic idiopathic urticaria: a randomised double‐blind study.

Abstract

Terfenadine, a potent and non-sedative antihistamine, was shown to be effective in chronic idiopathic urticaria in a double-blind crossover placebo controlled trial. An oral twice daily 60 mg dose of terfenadine was given and itch and wheal parameters were assessed daily. Despite the overall effectiveness of terfenadine, a variable response was noted which was similar to that shown in previous studies with other antihistamines.

Long‐term bradycardia caused by atrioventricular block can remodel the canine heart to detect the histamine H1 blocker terfenadine‐induced torsades de pointes arrhythmias

“…Experiment 2: At 2 weeks after the induction of complete atrioventricular block ( n =6), 3 or 30 mg kg −1 of terfenadine was orally administered as a powder using a gelatin capsule, which will provide therapeutic to supra‐therapeutic plasma concentrations as an anti‐histamine ( Ferguson et al ., 1985 ; Usui et al ., 1998 ) 2 h after the start of ECG monitoring. Initially, the low‐dose of terfenadine was orally administered, and then 2 days later, 10 times higher dose was orally administered.…”

Second‐ and third‐generation antihistamines in the treatment of urticaria

“…Terfenadine 60 mg twice a day or 120 mg once a day provides serum concentrations for optimal efficacy. Numerous studies have demonstrated terfenadine to be superior to placebo in the treatment of chronic urticaria (54,89–92). It has been shown to be similar in efficacy to both chlorpheniramine (93) and hydroxyzine 25 mg four times a day (94), but with less sedation, and was more effective than clemastine (92).…”

The pharmacology and mechanisms of action of histamine H1‐antagonists

“…The new H|antihistamines seem to be similar in efficacy to the majority of the classical antihistamines. Using terf"enadine in chronic idiopathic urticaria one can expect approximately 25% of patients to show a complete response and a further 50% a partial response [104]. Therefore, as with asthma and rhinitis, histamine is responsible for only some symptoms, other mediators also contributing to the overall pattern of disease.…”