Abstract
Objectives: An association between COVID-19 and anosmia has
been demonstrated worldwide. Calcium cations play an essential role in
odor transmission, including feedback inhibition. Therefore, it is
suggested that reducing intranasal free calcium cations with topical
chelating agent pentasodium diethylenetriamine pentaacetate may improve
olfactory function in patients with anosmia post COVID-19 infection.
Design: Prospective controlled clinical trial to test use of
pentasodium diethylenetriamine pentaacetate for post COVID-19 olfactory
loss.
Setting: ENT Department (Institution blinded for review).
Participants : Sixty-six adult patients with history of
confirmed COVID-19 and olfactory dysfunction persisted more than 90 days
after SARS-CoV-2 negative testing were included.
Main outcome measures: Participants were divided into 2 equal
groups receiving nasal spray containing either 0.9% sodium chloride or
2% pentasodium diethylenetriamine pentaacetate. Olfactory function was
assessed before treatment and 1 month later using the Sniffin’ Sticks
test. A carbon paste ion-selective electrode was developed for
quantitative analysis of calcium cation concentrations in nasal mucus
before treatment and 1 month later.
Results: After treatment with pentasodium diethylenetriamine
pentaacetate, there was a significant improvement from functional
anosmia to hyposmia compared with sodium chloride. In addition, the
decrease of calcium concentration was recorded after treatment with
pentasodium diethylenetriamine pentaacetate compared with sodium
chloride.
Conclusion: Based on the results of the proposed study, topical
use of pentasodium diethylenetriamine pentaacetate may be a useful
therapy for olfactory dysfunction after COVID-19.
Keywords : Anosmia; olfactory test; COVID-19.