Comparative effects of terfenadine and loratadine in the treatment of hay fever.

This double-blind, double-dummy, parallel-group study was undertaken in 40 patients with seasonal allergic rhinoconjunctivitis during the 1990 hay fever season. The patients were randomized and treated for seven days with either 120 mg terfenadine or 10 mg loratadine, each drug taken once daily in the morning. The severity of nasal congestion, rhinorrhea, sneezing, nasopharyngeal itching, and itchy, watery, red eyes was evaluated before and at the end of treatment. The global severity of symptoms was ranked daily by the patient on a diary card. Both treatment groups experienced a significant improvement of symptoms after treatment (p < 0.01), without any significant difference between the two study drugs. Terfenadine and loratadine significantly improved symptom severity by 69 and 55% compared with the baseline values, respectively. Headache and fatigue were reported in three loratadine-treated patients, and sedation in one patient. No side effects were observed in patients receiving terfenadine. This study confirmed that terfenadine 120 mg once daily is a safe and effective treatment for hay fever.