Background: OSA patients often struggle to comply with PAP therapy, and previous research has not shown INS to be effective. This study aimed to evaluate a new combination of INS and INAH for their efficacy in enhancing PAP adherence and alleviating CPAP-induced rhinitis symptoms in OSA patients.

Methods: From March to December 2022, a double-blind, double-dummy randomized control trial was conducted at Thammasat University Hospital involving PAP-treated OSA patients. Participants filled out online questionnaires or phone interviews at the second week and one month after starting CPAP therapy.

Results: 61 participants' data was analyzed, most of whom had severe OSA (73.7%), and there was no significant difference in the optimal pressure between the intervention and placebo groups (11.5 ± 4.0 vs 12.5 ± 2.9). At all time points, no significant differences were found in percent PAP usage greater than 4 hours (55% vs 44%, p = 0.67) or in total nasal symptom scores, Rhinoconjunctivitis Quality of Life, and visual analog scale scores. Furthermore, there were no significant differences in side effects such as dry throat, nasal congestion, and runny nose.

Conclusion: The preliminary findings of this study evaluating the effectiveness of azelastine hydrochloride and fluticasone propionate nasal spray in enhancing PAP adherence indicate that this combination may improve PAP usage and reduce CPAP-induced rhinitis symptoms. Further recruitment is underway to confirm these results