Patients attend 5 visits to the study site. On visit 1 medical history and concomitant medication are assessed and patients undergo a physical examination, a pregnancy test in case of women of child bearing potential, and, if necessary, a skin prick test. Blood is taken to estimate creatinine clearance. Inclusion and exclusion criteria are checked and, if they do not contradict study continuation, patients enter the screening period which ends in the morning of the day visit 2. If on this visit morning diary reports show sufficiently high nasal obstruction scores and study participation still complies with the inclusion and exclusion criteria, patients are randomized and start the treatment period taking the first dose at the study site. On visit 2 as well as on the following visits adverse events and use of medication are surveyed and compliance is checked. Visit 3, 4 and 5 are scheduled after one week of treatment, between treatment and post treatment observation period and at the end of the study respectively. On visit 5 there is a final physical examination and again females of childbearing potential undergo a pregnancy test. To assess how relevant for patients nasal obstruction and the effect of the study medication on nasal obstruction are questionnaires are completed on each visit.