AUTHOR=Ono Rie , Arita Ryutaro , Takayama Shin , Kikuchi Akiko , Ohsawa Minoru , Saito Natsumi , Suzuki Satoko , Ishii Tadashi 

TITLE=Kampo Medicine Promotes Early Recovery From Coronavirus Disease 2019-Related Olfactory Dysfunction: A Retrospective Observational Study

JOURNAL=Frontiers in Pharmacology

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2022.844072

DOI=10.3389/fphar.2022.844072

ISSN=1663-9812

ABSTRACT=Background: Olfactory dysfunction is a common symptom in patients with coronavirus disease 2019, and it significantly reduces patients’ quality of life. Effective treatments remain unknown.
Purpose: To assess the effect of Japanese traditional (Kampo) medicine on coronavirus disease 2019-related olfactory dysfunction. 
Study Design: Retrospective observational study.
Methods: In total, 87 patients aged ≥18 years with coronavirus disease 2019 and severe dysosmia or anosmia (numeric rating scale, ≥7) in isolation facilities in Miyagi Prefecture, Japan, were enrolled from October 2020 to March 2021. Patients were divided into the Kampo group (N=52) and the control group (N=35) based on the treatment received. Changes in numeric rating scale scores were evaluated at the first visit and 2 weeks after the first visit.
Results: The median reduction in the olfactory dysfunction score at both 1 and 2 weeks after the first visit was significantly greater in the Kampo group (6 and 8, respectively) than in the control group (3 and 7, respectively) (P=0.03 and P=0.04, respectively). We defined improvement in olfactory dysfunction as a median reduction in the olfactory dysfunction score of ≥5. Multiple logistic regression analysis demonstrated that only Kampo treatment was significantly associated with an improvement in olfactory dysfunction.
Conclusion: This study suggested that Kampo medication promotes early recovery from coronavirus disease 2019-related olfactory dysfunction.