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

In conclusion, high CQ dosage scheme (12g), given for 10 days, was not sufficiently safe to warrant continuation of that particular study arm. We therefore strongly recommend that this dosage is no longer used anywhere for the treatment of severe COVID-19, especially because in the real world older patients using cardiotoxic drugs should be the rule. No apparent benefit of CQ was seen regarding lethality in our patients so far, but we will still enroll patients in the low CQ dose group to complete the originally planned sample size.