Higher doses of Terfenadine and Loratadine. Acute and subchronic effects on psychomotor and actual driving performance.

Higher doses of antihistamines are advocated, especially for the treatment of bronchial asthma. Higher doses of so- called "old" antihistamines present the problem of sedation, resulting in the patients' unfitness to drive a car. Fourteen male and ten female volunteers received four separate treatments consisting of multiple terfenadine 120 mg bid, loratadine 20 mg OD, triprolidine 5 mg bid and placebo doses, over four consecutive days. This was done double- blind, with a dummy placebo following the daily loratadine dose, according to a cross- over design.