The efficacy of
terfenadine, a nonsedating H1
antihistamine, in the management of chronic idiopathic
urticaria was compared with
chlorpheniramine and placebo in a parallel multicenter trial. Subjects with symptoms of
hives for 3 days per week for at least 6 weeks were initially screened and admitted if no identifiable cause for symptoms could be determined. Patients entered a single-blind placebo period, and if
hives of moderate severity were present for at least 3 days during the week, they were randomly assigned in a double-blind fashion to take
terfenadine, 60 mg twice daily,
chlorpheniramine, 4 mg three times a day, or placebo for 6 weeks. Data were analyzed for 122 patients. Those patients receiving both active treatments noted significant improvement in symptoms:
pruritus, redness, number of
hives, and waking hours during which
hives were present, at the end of the first day of
therapy. Symptom control by
terfenadine was statistically superior to placebo during all 6 weeks, as rated by both patients and investigators. However, statistical significance was not achieved for
chlorpheniramine at all observation points.
Diphenhydramine was permitted as a relief medication for refractory symptoms and was taken by 52% of subjects receiving placebo, 26% taking
chlorpheniramine, and only 9% of patients who were receiving
terfenadine. In addition to providing superior symptom control,
terfenadine caused less drowsiness and
fatigue than
chlorpheniramine.
Terfenadine is a useful therapeutic agent for primary management of chronic idiopathic
urticaria.