Journal of Pharmaceutics & Pharmacology
Review Article
Repurposing of Adamantanes for the Treatment of COVID-19: Rationale and Perspectives
Butterworth Roger F
University of Montreal, Canada
Address for Correspondence:
Butterworth Roger F, Professor of Medicine, University of Montreal, 45143
Cabot Trail, Englishtown, NS, B0C 1H0, Canada; E-mail: rb@enceph.com
Submission: 14 August 2020;
Accepted: 10 September 2020;
Published: 16 September 2020
Copyright: © 2020 Butterworth Roger F. This is an open access article
distributed under the Creative Commons Attribution License, which
permits unrestricted use, distribution, and reproduction in any medium,
provided the original work is properly cited.
Abstract
Intensive efforts are underway in the search for novel antiviral agents
and in the repurposing of existing antivirals with the potential to
mitigate the effects of COVID-19. Amantadines represent a large
family of tricyclic agents some of which are known to manifest efficacy
against a range of viruses including influenza A and several human
and animal coronaviruses including SARS-CoV and HCoV-OC43 with
neuroinvasive characteristics. The adamantane derivative memantine
improves clinical scores and motor disabilities while reducing HCoVOC43
viral replication in a dose-dependent manner. Anti-viral actions
of memantine against HCoV are independent of the agent’s action
as a non-competitive NMDA receptor antagonist. Amantadine and
the novel spiroadamantane amine possess significant activity against
coronavirus 229E. Mechanisms proposed to date to account for the anti-
SARS CoV-2 actions of adamantanes include blocking of the viroporin
channel of the virus E protein preventing release of viral nucleus into
the host-cell cytoplasm and down-regulation of the host protease CTSL
and lysosomal disruption leading to decreased viral replication. Further
investigations are now required including the assessment of other
adamantanes as antivirals in the experimental setting and controlled
clinical trials to assess their safety and efficacy for the prevention and
treatment of COVID-19.