Manuka honey sinus irrigations in recalcitrant chronic rhinosinusitis: phase 1 randomized, single-blinded, placebo-controlled trial

Background: Manuka honey (MH) has significant antibiofilm activity in vitro and in vivo against Staphylococcus aureus, methicillin-resistant S aureus (MRSA), and Pseudomonas aeruginosa. This is the first randomized, single-blinded, placebo-controlled phase 1 clinical trial investigating the safety and preliminary efficacy of MH with augmented methylglyoxal (MGO) rinses in recalcitrant chronic rhinosinusitis (CRS). Methods: Patients were included after previously undergoing endoscopic sinus surgery and presenting with signs and symptoms of sinus infection with positive bacterial cultures on sinus swabs. Patients were randomized to receive 14 days of twice-daily 16.5% MH + 1.3 mg/mL MGO sinonasal rinses and concurrent 10 days of placebo tablets (MH), or 14 days of twice-daily saline sinonasal rinses and concurrent 10 days of culture-directed antibiotic therapy (CON). Safety observations included the University of Pennsylvania Smell Identification Test (UPSIT) and adverse-event (AE) reporting. Efficacy was assessed comparing microbiology results, Lund-Kennedy scores (LKSs), and symptom scores using the visual analog scale (VAS) and 22-item Sino-Nasal Outcome Test (SNOT-22). Results: Twenty-five patients completed the study. MH demonstrated a good safety profile with no major AEs and no changes in UPSIT. Six of 10 (60%) MH patients had a reduction in bacterial culture rate with 1 of 10 of those having negative cultures, compared with 12 of 15 (80%) in the control group with 7 of 15 having negative cultures upon completion of the study. Conclusion: This study concludes that twice-daily 16.5% MH augmented with 1.3 mg/mL MGO sinonasal rinses alone for 14 days is safe but not superior to culture-directed oral antibiotics and twice-daily saline rinses.