Comparison of efficacy and tolerability of terfenadine administered once daily versus twice daily in patients with chronic idiopathic urticaria.

The objective of this double-blind study, which is part of a multicenter study, was to determine whether terfenadine (120 mg once daily) has similar efficacy and tolerability to the standard dosage of 60 mg twice daily in the treatment of chronic urticaria. Forty-one patients were randomly allocated to two parallel groups and treated for 2 weeks with either regimen. Evaluation of efficacy was based on rating scales for investigator and patient. Primary endpoints were itch, number of wheals, wheal size, and the overall rating of efficacy. A similar improvement was seen in all variables. There were no statistically significant differences between groups. Both treatments were well tolerated.