Hydroxychloroquine Fails as Pre-exposure Prophylaxis for COVID-19 Save

Numerous previous studies have questioned the efficacy or protection afforded by hydroxychloroquine (HCQ) for COVID-19 and studies have show that HCQ has failed when given as post-exposure prophylaxis to health care workers (HCWs).  A new randomized controlled trial has shown that HCQ failed when given as 8 weeks of pre-exposure prophylaxis in hospital-based HCWs exposed to patients with COVID-19 patients. 

This randomized, double-blind, placebo-controlled clinical trial randomized 132 full-time, hospital-based HCWs (physicians, nurses, certified nursing assistants, emergency technicians, and respiratory therapists), of whom 125 were initially asymptomatic and had negative results for SARS-CoV-2 by nasopharyngeal swab. The trial was terminated early for futility before reaching a planned enrollment of 200 participants.  HCWs were given either placebo or HCQ 600 mg, daily 8 weeks.

Evaluable subjects included 125 (94.7%) of the randomozed cohort.

There was no significant difference in infection rates in (by nasal PCR) participants randomized to receive HCQ (6.3%) compared with placebo (6.6%; P > .99).

There were more mild adverse events with HCQ compared with placebo (45% vs 26%; P = .04) but discontinuation rates and QTc changes were similar between groups. 

HCQ should not be used as prophylaxis in HCW or others at high risk for COVID-19.