In particular, the protein‐processing inhibitors cycloheximide and anisomycin showed strong inhibitory activities against both CoVs. The HIV protease inhibitor lopinavir was more effective against SARS‐CoV‐1 than against MERS‐CoV. The antidiarrheal agent loperamide showed moderate inhibitory activitiy against both CoVs. The anti‐protozoal and emetic alkaloid with antibacterial properties, emetine, showed strong antiviral activity against MERS‐CoV. The antiparasitic drugs chloroquine, hydroxychloroquine, and mefloquine showed moderate antiviral activities against both CoVs. Cathepsin inhibitor, E‐64‐D, inhibited both as well. Two of the neurotransmitter inhibitors, chlorpromazine and triflupromazine also blocked both viruses (see Section 2) The DNA synthesis inhibitor gemcitabine was able to inhibit SARS‐CoV‐1 and MERS‐CoV with an EC50 value of 1.2 and 4.9 µM, respectively. Toremifene is an estrogen receptor 1 antagonist that inhibited both MERS‐CoV and SARS‐CoV‐1 (EC50, 12.9 and 11.97 µM, respectively).