Hydroxychloroquine Fails as Postexposure Prophylaxis for Covid-19 Save

Add this to the list of hydroxychloroquine (HCQ) letdowns in managing COVID-19 treatment or risk - prophylaxis with HCQ fails to prevent COVID-19 infection in those exposed to the SARS-CoV-2 virus. 

NEJM has reported a prospective, randomized, double-blind, placebo-controlled trial from the US and Canada wherein adults with household or occupational exposure to someone with confirmed Covid-19 were treated with either placebo or HCQ within 4 days of exposure.

Those treated with HCQ received 800 mg once, followed by 600 mg in 6 to 8 hours, then 600 mg daily for 4 additional days. The primary endpoint was the incidence of either laboratory-confirmed Covid-19 or illness compatible with Covid-19 within 14 days.

A total of 821 asymptomatic participants were enrolled and approximately 88% reported a high-risk exposure to a confirmed Covid-19 contact.

New Covid-19 illness risk did not differ significantly between those on HCQ (11.8%) or placebo (14.3%); the absolute difference was −2.4 percentage points (95% confidence interval, −7.0 to 2.2; P=0.35). Side effects were more common with hydroxychloroquine (40.1% vs. 16.8%), but none were serious adverse.

Hydroxychloroquine should not be used as postexposure prophylaxis to ward off COVID-19 infection.  Currently, for those exposed, the current standard of care is observation and quarantine.