Terfenadine once daily in chronic urticaria: a multi-centre double-blind comparison of terfenadine once daily versus twice daily

The objective of these three double-blind multi-centre studies was to determine whether terfenadine 120 mg once daily has similar efficacy and tolerability as the standard dosage of 60 mg twice daily in the treatment of chronic urticaria. A total of 252 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, i.e. itch, number of wheals, wheal size and an overall rating of efficacy. A similar improvement was seen in all variables, and there were no statistically significant differences between treatment groups. The power of the studies combined is greater than 80%, i.e. sufficient to state convincingly that treatment effects are not different. Both treatments were also equally well tolerated.