Multicenter double-blind comparative study of terfenadine and cetirizine in hay fever.

The efficacy and safety of terfenadine in the management of hay fever were compared with those of cetirizine in a multicenter, double-blind, parallel-group study, carried out during the 1990 spring pollen season. The patients were randomly assigned to one of two groups of treatment, 70 patients being given terfenadine 120 mg, and 72 patients cetirizine 10 mg, once daily for 7 days. The severity of the main symptoms was evaluated at baseline and after treatment by a 4-point rating scale. In addition, the overall symptom severity was recorded daily by the patient on a diary card. Both terfenadine and cetirizine produced significant relief of symptoms by the end of treatment, with a decrease in symptom severity ranging from 46 to 69% for terfenadine and from 40 to 55% for cetirizine. Adverse effects experienced by terfenadine- and cetirizine-treated patients were mainly drowsiness, with minor differences between the two groups. The results of this study confirmed previous experiences, showing that both terfenadine and cetirizine once daily should be regarded as effective drugs for the management of hay fever.