The antiviral efficacy of Remdesivir may be reduced if it is coadministered with chloroquine or hydroxychloroquine for COVID-19 patients, conveys a press release of the Food and Drug Administration (FDA) on 16 June, 2020. This implication was based on antagonistic potential of chloroquine on intracellular metabolic activation and antiviral action of remdesivir. Per se, the simultaneous use of remdesivir with chloroquine or hydroxychloroquine is not suggested.

Currently, the compromised antiviral activity has not been described in the clinical setting, but the FDA is continuing to assess data as it becomes available. In this context Patrizia Cavazzoni, MD, acting director of the FDA’s Center for Drug Evaluation and Research said “We understand that, as we learn more about these products, changes may be necessary based on new data – such as today’s updates for healthcare providers about a potential drug interaction and other important information about using remdesivir to treat COVID-19 patients,”

Remdesivir was approved for emergency use in May 2020 after the preliminary results from a National Institutes of Health study that revealed its efficacy for shorter recovery time in hospitalized COVID-19 patients.