Double-blind trials of clemastine ('Tavegil') in allergic rhinitis.

Two double-blind randomised trials are reported comparing the effectiveness of the antihistamines, clemastine and chlorpheniramine in comparable doses, in relieving the symptoms of allergic rhinitis. In the first trial, treating 58 adults seen in a general practice, both drugs were prescribed in tablet form; l mg. clemastine b.d. and 4 mg. chlorpheniramine b.d. The second trial was carried out in 42 patients attending a children's E.N.T. out-patient department and the drugs were prescribed as clemastine elixir (0.5 mg. b.d.) or as chlorpheniramine syrup (2 mg. b.d.). Both drugs were effective in providing symptomatic relief in a significant number of patients, and the overall efficacy of clemastine was marginally better than that of chlorpheniramine, especially in the second trial in children. Side-effects were minimal and drowsiness was not a problem.