Their effects can now be inhibited specifically by leukotriene receptor antagonists (Lipworth, 1999). Although they are not currently licensed for the treatment of chronic rhinosinusitis, randomised controlled studies have shown clinical efficacy with leukotriene receptor antagonists (Donnelly et al., 1995; Gros- sman et al., 1997; Shirasaki et al., 1998). Furthermore, Knapp et al. (1990) showed that 5-lipoxygenase inhibition reduced aller- gen induced nasal congestion and levels of leukotrienes in nasal lavage fluid. However, these drugs have been shown to be less efficacious than intra-nasal corticosteroids. For example in sea- sonal allergic rhinosinusitis, zafirlukast has been shown to be inferior to intra-nasal beclomethasone dipropionate on nasal symptoms and biopsy (Pullerits et al., 1999), and intranasal budesonide to be superior to montelukast in terms of peak nasal Rhinology, 38, 142–146, 2001 INTRODUCTION Chronic rhinosinusitis is a common condition, with increasing prevalence, occurring in up to 20% of the population (Lund- back, 1998). Although the condition does not result in hospita- lisation or mortality, it is distressing to patients and may result in absenteeism from work (Blaiss, 2000). Topically delivered intra-nasal corticosteroids are widely recognised to be the first- line anti-inflammatory treatment for allergic chronic rhinosinu- sitis, as reflected in guidelines (Lund, 1994). They exert their anti-inflammatory activity in a non-selective way by affecting a wide range of inflammatory and structural cells. Leukotrienes are important inflammatory mediators in the pathogenesis of allergic and non-allergic chronic rhinosinusitis (Bisgaard et al., 1986; Okuda et al., 1988; Naclerio et al., 1991). SUMMARY Although there is evidence from randomised controlled trials that leukotriene receptor antago- nists are efficacious in chronic rhinosinusitis there are still little data on their use in everyday real life clinical practice. We report on a pragmatic case series of 32 patients referred from pri- mary care with uncontrolled chronic rhinosinusitis (allergic or non-allergic) who have been treated with montelukast in our joint medical/surgical rhinology clinic. Patients’ symptoms were scored according to “facial pain”, “headache”, “nasal blockage”, “nasal discharge”, “sen- se of smell” and “daily activity”, and measurements of peak inspiratory nasal flow were made, before and after the introduction of montelukast 10mg/day. There were significant (p<0.05) improvements in subjective scoring for headache, nasal discharge & blockage, sense of smell and daily activity but not for facial pain, when montelukast was added along with other alte- rations in chronic rhinosinusitis medication (all receiving intra-nasal corticosteroids). Sub- group analysis of 10 patients, were the addition of montelukast was the only change to medi- cal therapy, showed significant (p<0.05) improvements in headache, nasal discharge and blockage and their daily activity. There was no significant improvemens in nasal peak inspi- ratory flow or spirometry. In conclusion, montelukast may be a useful therapeutic option in addition to standard therapy (ie intra-nasal corticosteroids or anti-histamines) when treating patients with chronic rhinosinusitis in a real life clinical setting. Keywords: montelukast, chronic rhinosinusitis, symptom scores, inspiratory flow, clinical set- ting * Received for publication: November 13, 2000; accepted: March 28, 2001 Effects of leukotriene receptor antagonist therapy in patients with chronic rhinosinusitis in a real life rhinology clinic setting* Andrew M. Wilson 1 , Paul S. White 2 , Quentin Gardiner 2 , Ramez Nassif 2 , Brian J. Lipworth 1 The Rhinology Joint Medical/Surgical Megaclinic 1 Asthma & Allergy Research Group, Department of Clinical Pharmacology & Therapeutics, University of Dundee, Dundee, Scotland, UK 2 Department of Otolaryngology, Ninewells Hospital & Medical School, University of Dundee, Dundee, Scotland, UK