Chloroquine for the 2019 novel coronavirus SARS-CoV-2

Abstract

h 0 A movement to reposition drugs has been initiated in recent ears [1] . In this strategy, it is important to use drugs that have een proven to be harmless and whose pharmacokinetics and ptimal dosage are well known. In the current episode of novel oronavirus (SARS-CoV-2) emergence [2] , we find a spectacular exmple of possible repositioning of drugs, particularly chloroquine. e had 20 years ago proposed to systematically test chloroquine n viral infections because it had been shown to be effective in itro against a broad range of viruses [3 , 4] . This drug has multiple ctivities, one of which is to alkalise the phagolysosome, which ampers the low-pH-dependent steps of viral replication, including usion and uncoating [4] . Other mechanisms of antiviral activity re poorly explained [5] . At the time of the severe acute respiratory syndrome (SARS)ssociated coronavirus epidemic [6] in 2003, several molecules ere tested to assess their effectiveness against this virus. Among hese, teicoplanin [7] , an antistaphylococcal agent, had proven effiacy in vitro , and this was also the case for chloroquine, at a 50% ffective concentration (EC 50 ) of approximatively 8 μM, and when dded to the cell culture either before of after exposure to the irus [5 , 8–10] . These findings ended up being forgotten because of he disappearance of SARS for reasons that are neither clear nor xplained [11] . The novel coronavirus currently isolated in China as been, with staggering speed, evaluated regarding its sensitivity o already used drugs [12] . Thus, the new antiviral drug remdeivir [13] as well as chloroquine, at an EC 50 of 1.1 μM, were found o be effective in preventing replication of this virus [12] . Chlorouine is perhaps one of the most prescribed drugs in the world 14 , 15] . As a matter of fact, all Europeans visiting malaria-endemic eographic areas for decades received chloroquine prophylaxis and ontinued it for 2 months after their return. In addition, local resients took chloroquine continuously, and treatment of malaria has ong been based on this drug. In addition, hydroxychloroquine has een used for decades at much higher doses (up to 600 mg/day) to reat autoimmune diseases [16] . It is difficult to find a product that urrently has a better established safety profile than chloroquine. urthermore, its cost is negligible. Hence, its possible use both in rophylaxis in people exposed to the novel coronavirus and as a urative treatment will probably be promptly evaluated by our Chiese colleagues. If clinical data confirm the biological results, the ovel coronavirus-associated disease will have become one of the implest and cheapest to treat and prevent among infectious resiratory diseases.