One of the efforts to combat the ongoing coronavirus disease 2019 (COVID-19), pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is repurposing drugs already in use.
Polyether ionophores are a family of natural products used as antibiotics. Often used in animals, they can inhibit gram-positive bacteria, including drug-resistant strains. They have also been seen to have antiviral activity against RNA and DNA viruses like influenza, HIV, and Zika. Studies reported that the ionophores salinomycin and monensin could inhibit Middle East respiratory syndrome (MERS-CoV), a coronavirus pathogen closely related to SARS-CoV-2. While the exact mechanism of antiviral activity in ionophores is unknown, it is likely that they interfere with the virus replication cycle.