Statements
Author Contributions:
H Koba:  Conceptualization, Investigation, Writing-Original Draft, Visualization,
T Yoneda: Data curation, Investigation,
T Kaneda: Investigation,
T Ueda:  Investigation,
H Kimura: Writing-Review & Editing, Visualization,
K Kasahara:  Supervision. Both authors have read and approved the final manuscript.
Acknowledgments:
We sincerely thank all persons who related with the diagnosis, treatment and nursing for the patients.
Statement of Ethics:
Informed consent from the patient was obtained, and a written consent for publication in this journal was also obtained from each patient. The ethics committee of the Komatsu Municipal Hospital approved the off-label use of both lopinavir/ritonavir and favipiravir before the administration of each drug, and the presentation or publication about these cases. Notation of prior abstract/presentation: This paper of any similar paper has not been submitted nor published in any other journal.
Disclosure: The authors have reported to Respiration that no potential conflicts of interest exist with any companies/organizations whose products or services may be discussed in the article.
Funding information:
This researach did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Acquisition of favipiravir was supported by retrospective registry study that was planned by National Center for Global Health and Medicine, Japan.
References
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