Recent survey seems to show that many drugs prevent C19
Link - https://www.biorxiv.org/content/10.1101/2020.03.20.999730v3.full
The charts are from the study, above link
Niclosamide is CRUSHING it here on these charts. Most common usage - tapeworms.
But it's also an antiviral.
https://www.ncbi.nlm.nih.gov/pubmed/23133371
Niclosamide is a proton carrier and targets acidic endosomes with broad antiviral effects.
(hmm, "targets acidic endosomes" that sounds like what chloroquine does - raises endosomal pH. and "broad antiviral effects")
"Here, we show that niclosamide, which is a weak lipophilic acid inhibited infection with pH-dependent human rhinoviruses (HRV) and influenza virus. Structure-activity studies showed that antiviral efficacy and endolysosomal pH neutralization co-tracked, and acidification of the extracellular medium bypassed the virus entry block."