Treatment of seasonal allergic rhinitis--a double blind, group comparative study of terfenadine and dexchlorpheniramine.

In order to evaluate the efficacy of and adverse reactions to terfenadine compared to dexchlorpheniramine, a double blind, group comparative study was carried out in 42 patients suffering from grass-pollen induced allergic rhinitis. The treatment was either terfenadine tablets 60 mg twice daily or dexchlorpheniramine tablets 6 mg twice daily. Nasal and eye symptoms as well as tiredness were rated daily on a scale from 0 (absent) to 3 (severe). Terfenadine and dexchlorpheniramine performed almost equally well in keeping symptoms at a mild level with a superiority of dexchlorpheniramine in the control of runny nose. Dexchlorpheniramine was associated with a significant increase in the score for tiredness in contrast to terfenadine which caused no significant change. Two patients in the group treated with dexchlorpheniramine stopped treatment because of tiredness. Other adverse reactions were few, mild and transient.