A Cluster-Randomized Trial of Hydroxychloroquine for Prevention of Covid-19.

Background: Current strategies for preventing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are limited to nonpharmacologic interventions. Hydroxychloroquine has been proposed as a postexposure therapy to prevent coronavirus disease 2019 (Covid-19), but definitive evidence is lacking.

Methods: We conducted an open-label, cluster-randomized trial involving asymptomatic contacts of patients with polymerase-chain-reaction (PCR)-confirmed Covid-19 in Catalonia, Spain.

Hydroxychloroquine for Early Treatment of Adults With Mild Coronavirus Disease 2019: A Randomized, Controlled Trial.

Background: No effective treatments for coronavirus disease 2019 (COVID-19) exist. We aimed to determine whether early treatment with hydroxychloroquine (HCQ) would be efficacious for outpatients with COVID-19.

Methods: Multicenter open-label, randomized, controlled trial conducted in Catalonia, Spain, between 17 March and 26 May 2020.