Effect of Topical Furosemide on Rhinosinusal Polyposis Relapse After Endoscopic Sinus Surgery: A Randomized Clinical Trial.

Importance Evidence from previous studies suggests that furosemide may be effective in reducing the recurrence of polyps after sinus surgery. However, the evidence is limited and insufficient, and further investigations are required. Objective To assess the effect of topical furosemide on recurrence rate of rhinosinusal polyposis after endoscopic sinus surgery. Design, Setting, and Participants Triple-blind randomized clinical trial of patients aged 18 to 60 years with chronic rhinosinusitis associated with polyposis who did not respond to medical treatment and were candidates for endoscopic sinus surgery at Besat Hospital, Hamadan University of Medical Sciences, from April 2014 to June 2015. Interventions Patients were randomly assigned to receive postoperative nasal spray, 2 puffs twice a day for 2 months, either 300 µg of furosemide per day or placebo. Main Outcomes and Measures Six months after surgery, the patients were examined for nasal and paranasal sinus polyposis using Meltzer endoscopic grading, computed tomographic (CT) scan of paranasal sinuses (PNS) scoring, Sino-Nasal Outcome Test (SNOT-22) scoring, and visual analog scale (VAS). Results Of 110 patients enrolled, 84 patients remained for analysis (53 men and 31 women; mean age in the furosemide group, 37.02 years, range, 18-58 years; mean age in the placebo group, 36.30 years, range, 18-60 years). Six months after the intervention, the grade of polyposis decreased in both groups, but this reduction was substantial in the furosemide group vs the placebo group. The severity of polyposis was significantly lower in the furosemide group vs the placebo group based on SNOT-22 scoring (difference, 8.05; 95% CI, 3.24-12.85) and VAS (difference, 0.81; 95% CI, 0.22-1.39) but not significantly different based on CT scan of PNS scoring (difference, 2.52; 95% CI, −0.35 to 5.39). The incidence of adverse effects (nasal irritation, headache, and constipation) were not significantly different between the 2 groups. Conclusions and Relevance These findings indicate that topical furosemide is a safe drug, with no important adverse effects, that can substantially reduce the severity of polyposis after endoscopic sinus surgery. Trial Registration Iranian Registry of Clinical Trials registration number: IRCT201403143186N5