Double-blind comparison of two antihistamines: mequitazine and dexchlorpheniramine

Summary

A double-blind clinical trial was carried out in 49 patients with allergic respiratory disorders to compare the efficacy and tolerance of mequitazine (10 mg/day) with that of slow-release dexchlorpheniramine maleate(12 mg/day). Two patients(1 in each group) withdrew because of intolerance on Day 2. After 1 week of treatment, 9 of the 25 patients on mequitazine and 4 of the 22 on dexchlorpheniramine showed marked improvement, enabling treatment to be stopped. All but 1 (on mequitazine) of the remaining patients showed some improvement. There was no statistically significant difference, however, between the two groups in terms of overall symptomatic improvement or changes in mean scores for individual symptoms. Twenty-two patients (11 in each group) continued treatment at the same dosage for a second week and improvement was maintained or increased in 8 on mequitazine and in 6 on dexchlorpheniramine. Dosage was reduced in the other 10 patients for the second week but only the 4 patients on mequitazine showed additional improvement. The fequency and severity of daytime drowsiness was significantly less in patients on mequitazine, and only a few other mild side-effects were reported. Overall, 76% of the mequitazine patients were assessed as showing an excellent response compared with 59% of those treated with dexchlorpheniramine.

Key Words::

• Mequitazine
• dexchlorpheniramine
• antihistaminics
• allergy