PATCH trial shows ‘no clinical benefit’ of hydroxychloroquine for COVID-19 prophylaxis
medwireNews: Prophylactic use of hydroxychloroquine does not reduce the risk for SARS-CoV-2 infection among hospital-based healthcare workers at high risk for exposure, suggest findings from a randomized controlled trial.
The 8-week PATCH study included 132 healthcare workers from two hospitals in Philadelphia, Pennsylvania, USA, who worked at least 20 hours per week in a hospital setting and had no known history of COVID-19. Participants were randomly assigned to receive hydroxychloroquine 600 mg/day or placebo, and were tested for SARS-CoV-2 infection with nasopharyngeal swabs at baseline, week 4, and week 8, or following onset of COVID-19 symptoms.
As reported in JAMA Internal Medicine, a comparable proportion of participants in the hydroxychloroquine and control arms tested positive for SARS-CoV-2 over the study period, at rates of 6.3% and 6.6%, respectively. Of the eight patients who tested positive, none required hospitalization for COVID-19; all were either asymptomatic or experienced mild disease with full recovery.
Therefore, there was “no clinical benefit of hydroxychloroquine administered daily for 8 weeks as pre-exposure prophylaxis,” and “we cannot recommend the routine use of hydroxychloroquine among [healthcare workers] to prevent COVID-19,” say Ravi Amaravadi (University of Pennsylvania) and team.
They note that the trial was terminated early before reaching the planned enrolment of 200 people, based on the second preplanned interim analysis for futility.
In the safety analysis, people treated with hydroxychloroquine had significantly higher rates of adverse events (AEs) than those given placebo, at 45% versus 26%. Diarrhea was the most frequently reported AE, affecting 32% and 12% of participants in the hydroxychloroquine and placebo groups, respectively.
There were no grade 3 or 4 AEs or cardiac events such as arrhythmia in the study, and no significant between-group difference in the median of changes in QTc interval from baseline to week 4.
However, Amaravadi and team caution that “the lack of QTc prolongation or arrythmias in our study’s cohort cannot be used to infer cardiac safety of hydroxychloroquine for active COVID-19 treatment” because “[m]yocardial inflammation associated with SARS-CoV-2 infection may increase susceptibility to potential cardiac effects of hydroxychloroquine.” Moreover, they note that “some studies have involved the combined use of azithromycin, a known QTc-prolonging compound, and hydroxychloroquine,” but azithromycin was not used in the PATCH trial.
The researchers point out that their study had a number of limitations. “Given the small sample size, we cannot exclude the possibility of an undetected modest potential prophylactic effect of hydroxychloroquine,” they say.
Furthermore, because the cohort largely comprised young and healthy participants with a median age of 33 years, the findings “may not be generalizable to other populations with increased risk because of advanced age or additional comorbidities,” they add.
medwireNews is an independent medical news service provided by Springer Healthcare Ltd. © 2020 Springer Healthcare Ltd, part of the Springer Nature Group
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