The place of hydroxychloroquine in the prevention and treatment of COVID-19 has been controversial, with contrasting claims and high-emotions. It was initially proposed as treatment or prophylaxis for COVID-19 based upon data reporting that chloroquine and hydroxychloroquine inhibited SARS-CoV-2 virus replication in cell culture systems. Interest accelerated rapidly as early reports from observational studies of clinical efficacy in COVID-19 patients emerged and hydroxychloroquine soon began to appear in clinical treatment guidelines.
