A novel bioinformatic approach for drug repurposing against emerging viral epidemics like Covid-19 is described. It exploits the COMPARE algorithm, a public program from the NCI to sort drugs according to their patterns of growth inhibitory profiles from a diverse panel of human cancer cell lines. The data repository of the NCI includes the growth inhibitory patterns of more than 55000 molecules. When drugs with purported anti-SARS-CoV-2 activities were used as seeds (e.g., hydroxychloroquine and ritonavir) in COMPARE, the analysis uncovered several drugs with fingerprints similar to the seeded drugs. Interestingly, the uncovered drugs were all reportedly known to exert antiviral activities, confirming that COMPARE analysis is valuable for predicting antiviral drug repurposing. Unlike pure in-silico approaches, this approach is biologically more relevant and able to pharmacologically correlate compounds regardless of their structures. This is an untapped resource, reliable and readily exploitable for drug repurposing against surprising viral outbreaks.