Question explored with the scientific record
what did harvey risch say about hydroxychloroquine use in Covid in 2020; you didn't include many studies of this question published in 2020-2023 that are much more definitive
The short version: the evidence here does not support Harvey Risch’s early claims that hydroxychloroquine was a proven treatment for COVID-19.
The evidence retrieved contains no statement from Harvey Risch. What it does contain is a set of studies published between 2020 and 2025 that consistently fail to show a net clinical benefit from hydroxychloroquine for COVID-19. The largest and most reliable trials — the RECOVERY trial, the SOLIDARITY trial, and the PRINCIPLE trial — all found no reduction in mortality or hospitalization [11, 12]. The PRINCIPLE trial, a randomized open-label platform trial in high-risk community patients, reported an odds ratio for hospitalization or death of 1.04 (95% CI 0.36 to 3.00), meaning no benefit [11]. A meta-analysis of controlled trials in nonsevere patients found that hydroxychloroquine did not improve viral clearance, clinical progression, or 5-day mortality, and it significantly increased gastrointestinal adverse effects (risk difference 0.59, 95% CI 0.55 to 0.64) [4]. An observational study of 336 hospitalized patients found that hydroxychloroquine use was associated with higher ICU admission (OR 8.05) and higher intubation rates (OR 7.99), with no mortality benefit [8]. The DisCoVeRy trial found no effect on biomarkers of endotheliopathy or coagulopathy [3].
The evidence that initially suggested benefit came from small, open-label, non-randomized studies with no control for confounding [6]. Those signals did not replicate in larger, better-designed trials. The FDA revoked its emergency use authorization in 2020 [9, 12]. The totality of the evidence here does not support the claim that hydroxychloroquine was an effective treatment for COVID-19.
My call: the evidence does not support the claim that hydroxychloroquine was an effective treatment for COVID-19. Confidence: high, based on multiple large randomized trials with hard clinical endpoints.
Sources examined 12
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The Potential Benefit of Beta-Blockers for the Management of COVID-19 Protocol Therapy-Induced QT Prolongation: A Literature Review
This literature review assesses whether cardio-selective beta-blockers, particularly bisoprolol, can mitigate QT interval prolongation caused by COVID-19 protocol therapies (chloroquine/hydroxychloroquine and azithromycin) and discusses potential additional benefits and underlyi…
DOI: 10.3390/scipharm88040055 -
Hydroxychloroquine pre-exposure prophylaxis for COVID-19 in healthcare workers
This study evaluates the efficacy of hydroxychloroquine as pre-exposure prophylaxis for COVID-19 among healthcare workers, finding no significant benefit in preventing infection.
DOI: 10.1093/jac/dkaa477 -
Hydroxychloroquine does not affect endotheliopathy or coagulopathy biomarkers in COVID-19: longitudinal results from the DisCoVeRy randomized trial
In a multicenter randomized trial of hospitalized COVID-19 patients, adding hydroxychloroquine to standard care did not modify longitudinal biomarkers of endotheliopathy or coagulopathy (angiopoietin-2, P-selectin, D-dimer), underscoring lack of vascular benefit and HCQ utility …
DOI: 10.1007/s10456-025-10023-7 -
Hydroxychloroquine for treatment of nonsevere COVID‐19 patients: Systematic review and meta‐analysis of controlled clinical trials
Hydroxychloroquine shows no net benefit for nonsevere COVID-19: it prevents early radiological progression but does not improve clinical outcomes, viral clearance, or mortality, and increases adverse effects.
DOI: 10.1002/jmv.26442 -
Hydroxychloroquine and chronic renal failure
A single-case report from Algeria detailing hydroxychloroquine use in an COVID-19 patient with severe renal impairment, describing dose adjustments, pharmacokinetic considerations, pharmaceutical care interventions, and observed changes in renal clearance during hospitalization.
DOI: 10.31579/2693-7247/012 -
Safety and Efficacy of Hydroxychloroquine and Chloroquine in Treatment of COVID-19: A Rapid Review of Evidence
Evidence on hydroxychloroquine and chloroquine for COVID-19 is inconclusive and conflicting, with some early trials suggesting potential benefit but overall safety and efficacy remain unproven, underscoring the need for high-quality, long-term randomized trials.
DOI: 10.18502/htaa.v4i1.5864 -
Efficacy of Hydroxychloroquine versus Clarithromycin in the Improvement of Dyspnea and Cough in Patients after the Treatment of Acute-Phase COVID-19
Post-acute COVID-19 patients randomized to hydroxychloroquine, clarithromycin, or placebo for four weeks showed HCQ reducing dyspnea most while clarithromycin best improved cough, but results were limited by small, single-center sample sizes.
DOI: 10.32592/ircmj.2023.25.4.2080 -
Impact of hydroxychloroquine on disease progression and ICU admissions in patients with SARS-CoV-2 infection
In hospitalized COVID-19 patients, hydroxychloroquine use was associated with higher ICU admission and increased need for intubation, without mortality benefit.
DOI: 10.1093/ajhp/zxab056 -
Drug Repurposing as an Effective Drug Discovery Strategy: A Critical Review
A comprehensive critical review arguing that drug repurposing offers a faster, cheaper alternative to de novo drug discovery, supported by computational data-driven methods and numerous case studies, but highlighting notable failures (e.g., hydroxychloroquine for COVID-19) to em…
DOI: 10.2147/dddt.s576701 -
Serious Cardiovascular Adverse Event Associated with Hydroxychloroquine with Azithromycin in Patient with COVID-19 : A Pharmacovigilance Analysis of the FDA Adverse Event Reporting System (FAERS)
A retrospective pharmacovigilance study using the FDA FAERS database to evaluate whether hydroxychloroquine (HCQ), alone or in combination with azithromycin (AZ), is associated with serious cardiovascular adverse events in COVID-19 patients, finding signals of increased risk and…
DOI: 10.36948/ijfmr.2022.v04i06.1012 -
The PRINCIPLE randomised controlled open label platform trial of hydroxychloroquine for treating COVID19 in community based patients at high risk
The PRINCIPLE trial assessed the effectiveness of hydroxychloroquine in reducing hospital admissions or deaths in community-based patients at high risk for COVID-19, finding no significant benefit from the treatment.
DOI: 10.1038/s41598-025-09275-6 -
COVID-19 and a Tale of Three Drugs: To Repurpose, or Not to Repurpose–That Was the Question
This article critically reviews COVID-19 drug repurposing with a focus on hydroxychloroquine, ivermectin, and remdesivir, outlining the evidence, controversies, regulatory responses, and ongoing debates about their efficacy, safety, and scientific integrity.
DOI: 10.3390/v17070881