Do We have the Evidence to Repurpose Levamisole for Treatment of COVID 19?

Abstract

The human civilization is reeling under the COVID19 pandemic with no promising news of any effective treatment against the infection to date. A number of drugs have been repurposed without any remarkable efficacy. Amidst the crisis, utilising immunomodulators for boosting host immunity to mitigate disease severity and infectivity appears a viable option. In this article, we have explored the contemporary scientific evidence about levamisole for its potential use in COVID 19. Though the primary pharmacological use of the drug is as an anthelminthic, its immunostimulatory action has been shown to increase T-cell function, neutrophilic chemotaxis and immunoglobulin production both in vitro and in vivo. Clinically, the drug has been used with limited success in the treatment of herpes and HIV. The potential role of the drug in COVID 19 stems from the fact that the immunostimulant action can initiate a strong immune response and surmount the surreptitious virus, which evades host cell immunity. However, great caution has to be exercised in deciding the dosing schedule because the drug-disease interaction, especially the fatal hyperimmune response, is unknown and unpredictable. Being a widely available drug, enlisted in the WHO List of Essential Medicine, without any major safety issue, the drug is already in clinical trials carrying out worldwide. As the pandemic continues to ravage mankind with unabated intensity, any favourable outcome is eagerly awaited from the ongoing trials with levamisole and other drugs.