Efficacy and tolerability of intranasally applied dimetindene maleate solution versus placebo in the treatment of seasonal allergic rhinitis

The aim of this study was to investigate the efficacy and tolerability of a 0.1 % dimetindene maleate spray (Fenistil(R) Nasal Dosierspray) compared t o placebo when applied intranasally. Dimetindene (dimetindene maleate, CAS 3614-69-5, DMM) is a very potent and well established Hi-receptor antagonis t. A total of 36 asymptomatic patients (17 female, 19 male), suffering from se asonal allergic rhinitis from grass pollen, were randomly assigned to treat ment with matching topicalnasal sprays with either dimetindene maleate 0.1 % or placebo as control in a double-blind, randomised, cross-over-design, w ith 2 weeks wash-out periods between. The trial period was chosen in a poll en-free time from 20th October to 5th November 1998 to guarantee asymptomat ic patients. The patients being allergic to grass pollen, verified by posit ive case history, positive skin prick test and positive nasal provocation t est, were challenged under controlled conditions with purified airborne gra ss pollen in the Vienna Challenge Chamber. The nasal spray were applied as single doses (1 puff = 0.14 mi of the respective solution with or without 0 .14 mg dimetindene maleate) in the evening before at 7.30 p.m. and in the m orning at 7.30 a.m. to each nostril exactly 15 min before the onset of alle rgen provocation. The dosage scheme relates to a daily dose of 0.56 mg DMM in the active treatment group. Subjective nasal and ocular symptoms were me asured on-line in time intervals of 30 min during the 4 h allergen provocat ion. The statistical analysis was a priori sequentially ordered to account for multiple testing and keep the 5% level of significance. All measured pr imary criteria, Total Nasal Symptom Score (p < 0.0001) calculated from the three single symptoms running of the nose (p = 0.0032) sneezing stimulus (p < 0.0001) and nasal itching (p < 0.0001), as well nasal secretion (p = 0.0 031), resulted consistently in a statistically significant and clinically r elevant superiority of 0.1 % DMM compared to placebo. The same superior tre atment effect was observed for all the other criteria, despite the nasal fl ow, but including the ocular variables. This can be interpreted as a positi ve efficacy also in secondary allergic conjunctivitis. No systemic or topic al adverse events were reported. The results of the study demonstrate that 0.1 % DMM as nasal spray is an efficient and safe application form for pati ents suffering from seasonal allergic rhinitis.