Treatment of chronic urticaria with terfenadine and ranitidine. A randomized double-blind study in 45 patients

45 patients with chronic urticaria were randomized to double blind therapy with terfenadine an H1-antihistamine or ranitidine, an H2-antihistamine, or a combination of both drugs. The therapeutic response was assessed by diary scores. The primary effect variable was "itching". The inference-statistical evaluation of the patient scores showed varying therapeutic effects. The Type-I error was p = 0.015. Itching was reported to be significantly lower by patients receiving both drugs than by those who were given terfenadine alone, while ranitidine in monotherapy had no significant effect on itching. A similar trend was seen in assessment of the severity of weals, while the treatment regimens had no influence on swelling.