Olopatadine versus levocetirizine in chronic urticaria: an observer-blind, randomized, controlled trial of effectiveness and safety.

OBJECTIVES: Chronic urticaria (CU) is characterized by frequent appearance of wheals for ≥ 6 weeks. This study was undertaken to compare effectiveness and safety of olopatadine, a newer antihistamine with additional anti-inflammatory properties, in treating CU in comparison to the established second-generation antihistamine levocetirizine.

METHODS: A single center, assessor-blind, randomized (1:1), active-controlled, parallel group, Phase IV trial (CTRI/2011/08/001965) was conducted with 120 adult CU patients of either sex. Subjects received either olopatadine (5 mg b.i.d.) or levocetirizine (5 mg/day) for 9 weeks, continuously for first 4 weeks and then on demand basis for last 5 weeks. Primary outcome measures were urticaria activity score (UAS) and urticaria total severity score (TSS). Routine hematological and biochemical tests and treatment-emergent adverse events were monitored for safety.

RESULTS: Data from 54 subjects on olopatadine and 51 on levocetirizine were analyzed for effectiveness. UAS and TSS values declined significantly with both drugs over the treatment period but the reduction was greater with olopatadine. Adverse event profiles were comparable with sedation being the commonest complaint.

CONCLUSIONS: Olopatadine is a safe and more effective alternative to levocetirizine in the treatment of CU.