MYTH: Hydroxychloroquine is a safe and effective treatment and prophylaxis for COVID-19
FACT: There is no evidence from high quality clinical trials that hydroxychloroquine is effective in treating or preventing COVID-19, and it is associated with a significant number of adverse effects, including death
By: Joseph Osmundson
Last updated: Updated May 27, 2020
Early in the COVID-19 pandemic, there were reports from small clinical studies that the anti-malaria drug hydroxychloroquine, alone or in combination with an antibiotic such as azithromycin, was an effective treatment for SARS-CoV-2 (the virus that causes COVID-19). Hydroxychloroquine modulates the immune system by increasing the pH of lysosomes, which are enzyme filled spheres that break down pathogens in immune system cells, decreasing the immune cells’ activity. Early hypotheses about COVID-19 suggested that altering the biology of lysosomes in this way may also inhibit the ability of SARS-CoV-2 to enter cells.
The use of hydroxychloroquine for COVID-19 treatment became frequent in critical care situations, and researchers in India began testing its effectiveness as prophylaxis.
However, as soon as larger clinical trials with control groups were published or the original data were reanalyzed, it became clear that hydroxychloroquine did not decrease the likelihood of death or shorten the duration of symptoms. Meta-analysis recently confirmed the lack of significant effect. Moreover, hydroxychloroquine was associated with adverse effects, including heart complications such as de-novo ventricular arrhythmia, leading to death.
Both the World Health Organization’s Solidarity trial and the United Kingdom’s RECOVERY trial have ceased evaluation of hydroxychloroquine after results demonstrated it was ineffective. Published results from a postexposure prophylaxis study also showed no efficacy. The use of hydroxychloroquine for treatment or prophylaxis of COVID-19 is not supported by science.