Chloroquine diphosphate in two different dosages as adjunctive therapy of hospitalized patients with severe respiratory syndrome in the context of coronavirus (SARS-CoV-2) infection: Preliminary safety results of a randomized, double-blinded, phase IIb clinical trial (CloroCovid-19 Study)

Mayla Borba; Fernando de Almeida Val; Vanderson Sousa Sampaio; Marcia Araujo Alexandre; Gisely Cardoso Melo; Marcelo Brito; Maria Mourao; Jose Diego Brito Sousa; djane Baia-da-Silva; Marcus Vinitius Farias Guerra; Ludhmila Hajjar; Rosemary Costa Pinto; Antonio Balieiro; Felipe Gomes Naveca; Mariana Xavier; Alexandre Salomao; Andre Siqueira; Alexandre Schwarzbolt; Julio Henrique Rosa Croda; Mauricio Lacerda Nogueira; Gustavo Romero; Quique Bassat; Cor Jesus Fontes; Bernardino Albuquerque; Claudio Daniel-Ribeiro; Wuelton Monteiro; Marcus Lacerda

The preliminary findings from CloroCovid-19 trial suggest that the higher dosage of CQ (12 g total dose over 10 days) in COVID-19 should not be recommended because of safety concerns regarding QTc prolongation and increased lethality, in the Brazilian population, and more often in older patients in use of drugs such as azithromycin and oseltamivir, which also prolong QTc interval. Among patients randomized to the lower dosage group (5 days of treatment, total dose 2.7 g), given the limited number of patients so far enrolled, it is still not possible to estimate a clear benefit of CQ in patients with severe ARDS. Preliminary data on viral clearance in respiratory secretions in our confirmed cases are also indicative of little effect of the drug at high dosage. More studies initiating CQ prior to the onset of the severe phase of the disease are urgently needed.