Sodium Citrate in Smell Retraining for People With Post-COVID-19 Olfactory Dysfunction

Summary

The goal of this pilot study is to assess the feasibility and impact of using sodium citrate nasal spray as an adjunct to olfactory retraining in participants with long-term post-COVID-19 olfactory dysfunction. The main questions it aims to answer are: * Is sodium citrate nasal spray in addition to smell retraining feasible for participants to use in terms of participant need/desire, adherence, and adverse events? * Does sodium citrate nasal spray in addition to smell retraining further improve smell as compared to normal saline spray and smell retraining? Participants will: * Provide consent for enrollment. * Undergo smell testing via Sniffin' Sticks. * Use a nasal spray (either sodium citrate or normal saline) followed by olfactory retraining twice a day for 12 weeks. * Return for follow-up Sniffin' Sticks testing. Researchers will compare the sodium citrate group and the normal saline group to determine differences in smell improvement.

Timeline

Start

2023-12-01

Primary completion

2025-12

Completion

2025-12

Publications

• Background Bacon DR, Onuorah P, Murr A, Wiesen CA, Oakes J, Thorp BD, Zanation AM, Ebert CS Jr, Wohl D, Senior BA, Kimple AJ. COVID-19 related olfactory dysfunction prevalence and natural history in ambulatory patients. Rhinol Online. 2021;4(4):131-139. doi: 10.4193/rhinol/21.034. Epub 2021 Aug 13.
• Background Kattar N, Do TM, Unis GD, Migneron MR, Thomas AJ, McCoul ED. Olfactory Training for Postviral Olfactory Dysfunction: Systematic Review and Meta-analysis. Otolaryngol Head Neck Surg. 2021 Feb;164(2):244-254. doi: 10.1177/0194599820943550. Epub 2020 Jul 14.
• Background Wu TJ, Yu AC, Lee JT. Management of post-COVID-19 olfactory dysfunction. Curr Treat Options Allergy. 2022;9(1):1-18. doi: 10.1007/s40521-021-00297-9. Epub 2022 Jan 4.
• Background Panagiotopoulos G, Naxakis S, Papavasiliou A, Filipakis K, Papatheodorou G, Goumas P. Decreasing nasal mucus Ca++ improves hyposmia. Rhinology. 2005 Jun;43(2):130-4.
• Background Whitcroft KL, Merkonidis C, Cuevas M, Haehner A, Philpott C, Hummel T. Intranasal sodium citrate solution improves olfaction in post-viral hyposmia. Rhinology. 2016 Dec 1;54(4):368-374. doi: 10.4193/Rhino16.054.
• Background Whitcroft KL, Ezzat M, Cuevas M, Andrews P, Hummel T. The effect of intranasal sodium citrate on olfaction in post-infectious loss: results from a prospective, placebo-controlled trial in 49 patients. Clin Otolaryngol. 2017 Jun;42(3):557-563. doi: 10.1111/coa.12789. Epub 2016 Dec 7.
• Background Philpott CM, Erskine SE, Clark A, Leeper A, Salam M, Sharma R, Murty GE, Hummel T. A randomised controlled trial of sodium citrate spray for non-conductive olfactory disorders. Clin Otolaryngol. 2017 Dec;42(6):1295-1302. doi: 10.1111/coa.12878. Epub 2017 Apr 17.
• Background Whitcroft KL, Gunder N, Cuevas M, Andrews P, Menzel S, Haehner A, Hummel T. Intranasal sodium citrate in quantitative and qualitative olfactory dysfunction: results from a prospective, controlled trial of prolonged use in 60 patients. Eur Arch Otorhinolaryngol. 2021 Aug;278(8):2891-2897. doi: 10.1007/s00405-020-06567-7. Epub 2021 Jan 20.

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