EFFICACY OF CHLOROQUINE AND HYDROXYCHLOROQUINE IN THE TREATMENT AND PREVENTION OF CORONA VIRUS INFECTION.

Abstract

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged as a major global public health challenge and prompted an urgent search for effective antiviral therapies. Chloroquine and hydroxychloroquine attracted considerable attention because of their established antimalarial activity, immunomodulatory properties, and reported in vitro antiviral activity against several viruses, including coronaviruses. This review aimed to evaluate the potential antiviral activity, clinical evidence, safety, and proposed mechanisms of action of chloroquine and hydroxychloroquine against COVID-19. Relevant in vitro and in vivo studies, clinical trials, original research articles, and consensus reports were identified through databases and sources including PubMed, Web of Science, EMBASE, Scopus, Google Scholar, the World Health Organization, and clinical trial registries. The literature search focused on terms including chloroquine, hydroxychloroquine, antiviral drugs, COVID-19, SARS-CoV-2, and coronavirus treatment. Evidence from laboratory studies demonstrated inhibition of SARS-CoV-2 replication, while proposed mechanisms included interference with pH-dependent viral entry and replication and modulation of inflammatory responses. Early clinical reports suggested possible reductions in viral load and disease duration; however, these findings were based largely on small or non-randomized studies, and subsequent evidence did not establish consistent clinical efficacy. The combination of hydroxychloroquine with azithromycin was also investigated, but the available early evidence was insufficient to establish its effectiveness and raised concerns regarding safety. Although chloroquine and hydroxychloroquine possess established pharmacological properties and demonstrated antiviral activity in vitro, clinical efficacy for the treatment or prevention of COVID-19 was not established. Further well-designed clinical studies were therefore required to determine their therapeutic value, optimal dosage, duration of treatment, and safety profile.