In some patients, symptoms of allergic rhinitis can be severe and therefore rapid relief is required. There are many treatment options for allergic rhinitis but histamine H1 blockers and topical corticosteroids represent the first-line treatment. Although the latter drugs are usually very effective on nasal symptoms, their onset of action is around 24 h. Thus drugs that are more rapidly effective are of interest.
Recently 400 French specialists (in Allergy, ENT and Pneumology) met together to define the criteria for selecting a drug for the treatment of rhinitis. Twelve criteria were proposed and rapid onset of action (less than 24 h) was among the foremost designated criteria.
In the first trial, a comparison of mizolastine (10 mg once daily [od]) with cetirizine (10 mg od) and placebo was carried out in the management of seasonal allergic rhino-conjunctivitis (SAR) with special focus on onset of action. A total of 375 patients were included in this European multicentric, randomized, parallel group and placebo-controlled study. By comparison to placebo, both cetirizine and mizolastine reduced significantly nasal and ocular symptoms during the 28-day follow-up trial. The percentage of responders ranged from 40% in the placebo group to 55% in the mizolastine group and 53% in the cetirizine group. Both active drugs were effective from the first intake with a rapid onset within 2 h. However, mizolastine was more rapidly and more profoundly effective than cetirizine during the first 12 h.
A second trial included 257 patients suffering from perennial allergic rhino-conjunctivitis (PAR) in a 4-week double-blind placebo-controlled multicentric study. During the study, patients recorded, using a diary card, ocular and nasal symptoms, including nasal blockage. The mean values of nasal score between day 1, 14 and 28 in the mizolastine group were statistically significantly lower than those in the placebo group. The mean values of ocular score showed a statistical difference in recordings between day 1 and day 14 in favour of the mizolastine group.
Mizolastine was an effective drug both in SAR and PAR with a rapid onset of action. Mizolastine relieved symptoms more effectively than cetirizine (SAR) and placebo (SAR and PAR) at the beginning of treatment.