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.