Investigating Side Effects of Existing Drugs Used in Covid-19 Treatment

Following the rapid spread and evolution of the novel Corona virus starting in December 2019, the lack of a vaccine or a medication that proved to be effective for Covid-19 was addressed as a major concern by the World Health Organization (WHO), the Center for Disease Control and Prevention (CDC), and the U.S. Food and Drug Administration (FDA) [1]. Accordingly, physicians from countries like China and Korea rushed to provide some potential treatment for Covid-19 from their experience in treating patients of the novel Coronavirus - they used antiviral medications like lopinavir, ritonavir, chloroquine, hydroxychloroquine, ribavirin, interferon, remdesivir, sofosbuvir, nitazoxanide, favipiravir, ivermectin, etc. [1]-[3]. These drugs showed improvement in conditions of Covid-19 patients when used individually, or sometimes using a combination of multiple of them. This does not mean that any combinations of these drugs could be beneficial. Some combinations can be lethal and may lead to increasing health risks or mortality. The drugs are being used in vitro (i.e., on cells in a laboratory for experiments) and vivo (i.e., on humans or animals as clinical trials). In vitro analysis, the chemical structure of the drug and the disease are analyzed to generate a hypothesis on the performance of the drug, then the hypothesis is tested in vivo to measure the actual performance of the drug on a living creature. Although these drugs showed promising results with proper dosage, overdose and incorrect combination with other drugs sometimes proved to be lethal. The effectiveness and side-effects of some of these drugs as reported by recent researchers and trials are described in this paper. We address some related research questions concerning the side effects of the covered drugs and their interaction with other drugs based on some well tested results extracted from approved web sites of drug-drug interactions. The findings are interesting and confirmed favipiravir as the most effective and safe compared to the others, and this coincides with and supports the announcement by Turkish Ministry of Health where favipiravir has been used in treating COVID-19 patients since the early days.