A Comparative Study of Clinical Efficacy And Tolerability Of Second Generation (Cetirizine) and Third Generation (Levocetirizine) Antihistaminics In Seasonal Allergic Rhinitis

Newer antihistaminics are coming up for clinical uses with modifications in the chemical structure of the antihistaminics already in use e.g. cetirizine (racemate mixture) and levocetirizine (R-enantiomer). So, “A comparative study of clinical efficacy and tolerability of levocetirizine over cetirizine in seasonal allergic rhinitis (SAR) was carried out. Sixty patients of seasonal allergic rhinitis were enrolled in an open, randomized and parallel group study. After taking informed consent patients were randomly divided into 2 groups. Group A received cetirizine 10mg once daily orally and Group B levocetirizine 5 mg daily for 4 weeks. Baseline total symptom complex score and nasal congestion score were noted prior to therapy and then weekly up to 4 weeks. Efficacy of treatment was measured according to total rhinitis symptom score and nasal congestion score whereas tolerability of the treatment regimen compared according to the observations of side effects. All observations thus made were statistically analysed. Total symptom complex score was improved by 99% in group A and 98.3% in group B which was almost similar. The improvement in the nasal congestion score was significantly more (95.8% in group B as compared to 57.7% in group A). Side effects were comparable except sedation and fatigue which were more in group A. Both cetirizine and levocetirizine were equally effective in controlling the SAR but levocetirizine definitely scored over cetirizine as far as symptoms of nasal congestion were concerned and also has cause less side effects. Levocetrizine may be better option for the treatment of SAR both in terms of efficacy and safety.