Mequitazine and dexchlorpheniramine in perennial rhinitis. A double-blind cross-over placebo-controlled study.

The therapeutic effect and adverse reactions of two antihistamines, mequitazine and dexchlorpheniramine were double-blindly compared both to placebo, to each other and to the pre-treatment status in 29 adult patients suffering from perennial rhinitis. Dexchlorpheniramine relieved the rhinitis symptoms significantly (p less than 0.01) better compared to placebo while mequitazine did not differ from placebo. 20 out of 29 patients chose dexchlorpheniramine as their favourite drug. Dexchlorpheniramine reduced all the separate symptoms studied (obstruction, rhinorrhoea, sneezing) significantly, mequitazine relieving merely rhinorrhoea. In anterior rhinoscopy mucosal congestion was reduced both by dexhlorpheniramine (p less than 0.01) and by mequitazine (p less than 0.05) but secretion or lividity showed no difference between the active drugs and placebo. The occurrence of side-effects was not significantly different between the drugs. In controlling perennial rhinitis symptoms mequitazine was markedly inferior to dexchlorpheniramine and only slightly better than placebo.