Letter to the Editor

Ivermectin Treatment for COVID-19

Masashi Ohe https://orcid.org/0000-0002-6684-6688
Author Information & Copyright
Department of Internal Medicine, JCHO Hokkaido Hospital, Sapporo, Japan
Corresponding author Masashi Ohe, Department of Internal Medicine, JCHO Hokkaido Hospital, 1-8-3-18 Nakanoshima, Toyohira-ku, Sapporo 062-8618, Japan Tel: 81-11-831-5151, Fax: 81-11-821-3851, E-mail: oektsp1218@sweet.ocn.ne.jp

Copyright © 2021 Ewha Womans University School of Medicine. This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Published Online: Oct 31, 2021


The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak that originated in late 2019 has become a serious global threat to human health. Presently, there are no drugs approved to combat the disease (coronavirus disease 2019, COVID-19). Therefore, it is important to find effective drugs against COVID-19 and to conduct clinical trials of these drugs. Drug repurposing is a well-known strategy applied to redeploy existing licensed drugs for newer indications, thereby providing the quickest possible transition from bench to bedside for meeting therapeutic needs. At present, several existing licensed drugs such as tetracycline (e.g., doxycycline), macrolide antibiotics (e.g., azithromycin), corticosteroids (e.g., prednisolone and dexamethasone), and IL-6 inhibitor (e.g., tocilizumab), have been used because of their potential efficacy in inhibiting COVID-19. Recently, the anti-SARS-CoV-2 effects of macrolide antiparasitics (e.g., ivermectin, IVM) have attracted considerable attention.

IVM is also an inhibitor of SARS-CoV-2, with a single treatment causing approximately 5,000-fold reduction in the virus at 48 hours in cell culture [1]. The mechanism by which IVM inhibits SARS-CoV-2 is thought to be via the inhibition of the nuclear import of viral and host proteins. Importin α/β1, a host protein, is a heterodimer that binds to the SARS-CoV-2 cargo protein and moves it into the nucleus, where the complex falls apart and the viral cargo can reduce the host cell’s antiviral response. IVM destabilizes the importin α/β1 heterodimer, preventing it from binding to viral protein and thus from entering the nucleus. As a result, the inhibition of antiviral responses is likely to be reduced, leading to a normal, more efficient antiviral response [1]. IVM also inhibits the binding of the SARS-CoV-2 spike protein to ACE2 [2]. Besides the anti–SARS-CoV-2 effects, IVM possesses anti-inflammatory and immunomodulatory effects to reduce the production of IL-6, IL-8, and TNF-α, in a dose-dependent manner [3].

Regarding IVM treatment for mild and moderate COVID-19, Ahmed et al. [4] reported that a 5-day course of IVM (12 mg daily) for COVID-19 reduced the duration of the illness. Prasad [5] reported a case of COVID-19 with pulmonary lesion successfully treated with the early administration of IVM (6 mg twice daily for 3 days), azithromycin (500 mg daily for 5 days), doxycycline (100 mg twice daily for 5 days), and prednisolone (50 mg daily for 5 days) followed by dexamethasone (6 mg daily).

COVID-19 is characterized by early exponential viral replication, cytokine-associated organ damage, and thrombosis. Severe COVID-19 involves this cytokine-associated organ damage, including acute respiratory distress syndrome (ARDS). Elevated levels of blood IL-6, IL-8, IL-10, and TNF-α were noted in COVID-19–induced ARDS [6]. COVID-19–induced ARDS was reported to be effectively treated with cytokine suppression, using a combination of IVM (12 mg single dose) and tocilizumab (240 mg single dose) [7]. Rajter et al. [8] reported that additional IVM (200 µg/kg daily) treatment was associated with lower mortality during treatment of COVID-19, especially in patients with severe pulmonary involvement. A combination of IVM (200 µg/kg daily for 2 to 3 days) and doxycycline (100 mg twice daily for 5 to 10 days) reduced the time to recovery and the percentage of patients who progressed to a more advanced stage of the disease; in addition, this treatment reduced the mortality rate in patients with severe COVID-19 from 22.72% to 0% compared to standard care [9].

Taken together, treatment with IVM alone or in combination with other drugs may show efficacy in COVID-19 in mild to severe stages and may be beneficial throughout the course of COVID-19.

In any case, clinical trials need to be conducted to better assess the optimal doses and durations as well as the efficacy and tolerability of these treatments before they can be adopted on a wider basis.

REFERENCES

1.

Caly L, Druce JD, Catton MG, Jans DA, Wagstaff KM. 2020; The FDA-approved drug ivermectin inhibits the replication of SARS-CoV-2 in vitro. Antiviral Res 178104787

2.

Lehrer S, Rheinstein PH. 2020; Ivermectin docks to the SARS-CoV-2 spike receptor-binding domain attached to ACE2. In Vivo 34:3023-3026

3.

Zhang X, Song Y, Ci X, An N, Ju Y, Li H, et al. 2008; Ivermectin inhibits LPS-induced production of inflammatory cytokines and improves LPS-induced survival in mice. Inflamm Res 57:524-529

4.

Ahmed S, Karim MM, Ross AG, Hossain MS, Clemens JD, Sumiya MK, et al. 2021; A five-day course of ivermectin for the treatment of COVID-19 may reduce the duration of illness. Int J Infect Dis 103:214-216

5.

Prasad A. 2020; Early administration of ivermectin, azithromycin & doxycycline along with I.V. prednisolone in a case of COVID-19 disease may lead to early recovery?. Int J Pharm Chem Anal 7:149-150

6.

Wang J, Yang X, Li Y, Huang JA, Jiang J, Su N. 2021; Specific cytokines in the inflammatory cytokine storm of patients with COVID-19-associated acute respiratory distress syndrome and extrapulmonary multiple-organ dysfunction. Virol J 18:117

7.

Chuang TY, Tsai MH, Wu LM, Ho SJ, Yeh PS, Liu YL, et al. 2021; Successful treatment of tocilizumab and ivermectin for a patient with ARDS due to COVID-19. J Microbiol Immunol Infect 54:147-148

8.

Rajter JC, Sherman MS, Fatteh N, Vogel F, Sacks J, Rajter JJ. 2021; Use of ivermectin is associated with lower mortality in hospitalized patients with coronavirus disease 2019: the ivermectin in COVID nineteen study. Chest 159:85-92

9.

Hashim HA, Maulood MF, Ali CL, Rasheed AM, Fatak DF, Kabah KK, et al. 2021; Controlled randomized clinical trial on using ivermectin with doxycycline for treating COVID-19 patients in Baghdad, Iraq. Iraqi JMS 19:107-115