National Center for Biotechnology Information NCBI NLM MEDLINE covid-19 sars-cov-2 humans pubmed abstract nih national institutes of health national library of medicine pandemics research support non-u.s. gov't adult female male aged middle aged Clinical Trial Randomized Controlled Trial Double-Blind Method anti-bacterial agents / therapeutic use pneumonia disease outbreaks betacoronavirus dose-response relationship drug antiviral agents / administration & dosage antiviral agents / therapeutic use* viral / drug therapy* brazil phase ii antiviral agents / adverse effects chloroquine / therapeutic use azithromycin / therapeutic use coronavirus infections / drug therapy* pmid:32330277 doi:10.1001/jamanetworkopen.2020.8857 mayla gabriela silva borba fernando fonseca almeida val clorocovid-19 team chloroquine / administration & dosage chloroquine / adverse effects chloroquine / analogs & derivatives* oseltamivir / therapeutic use tertiary care centers