SynthesisPloS one2021
The efficacy and safety of hydroxychloroquine for COVID-19 prophylaxis: A systematic review and meta-analysis of randomized trials.
Synthesis in PloS one, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 28 papers, 4 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
28 citing papers in PubMed, 4 syntheses or guidelines pooled it, 53 citations in OpenAlex.
- Repurposed drug studies on the primary prevention of SARS-CoV-2 infection during the pandemic: systematic review and meta-analysis.BMJ open respiratory research · 2023Pooled it
- Mortality, viral clearance, and other clinical outcomes of hydroxychloroquine in COVID-19 patients: A systematic review and meta-analysis of randomized controlled trials.Clinical and translational science · 2021Pooled it
- Prophylaxis against covid-19: living systematic review and network meta-analysis.BMJ (Clinical research ed.) · 2021Pooled it
- Use of hydroxychloroquine to prevent SARS-CoV-2 infection and treat mild COVID-19: a systematic review and meta-analysis.Jornal brasileiro de pneumologia : publicacao oficial da Sociedade Brasileira de Pneumologia e Tisilogia · 2021Pooled it
- Hydroxychloroquine for prophylaxis of COVID-19 in health workers: A randomized clinical trial.PloS one · 2022Trial
- The future is now: our experience starting a remote clinical trial during the beginning of the COVID-19 pandemic.Trials · 2021Trial
- Safety of Hydroxychloroquine for COVID-19 Prophylaxis in Healthcare Workers: A Cross-Sectional Study.Cureus · 2025Article
- A Roadmap for the Application of Convalescent Plasma and Hyperimmune Globulins in Emerging Viral Outbreaks.TheScientificWorldJournal · 2025Review
- The efficacy and safety of hydroxychloroquine for COVID-19 prophylaxis and clinical assessment: an updated meta-analysis of randomized trials.Journal of thoracic disease · 2024Article
- A narrative review on adverse drug reactions of COVID-19 treatments on the kidney.Open medicine (Warsaw, Poland) · 2024Review
- Analysis of the Prophylactic use of Hydroxychloroquine at the Beginning of the COVID-19 Pandemic Among Physicians.Infectious diseases & clinical microbiology · 2022Article
- Potential interactions between antineoplastic agents and medicines used to treat Covid-19.Journal of oncology pharmacy practice : official publication of the International Society of Oncology Pharmacy Practitioners · 2022Article
- Safety of Short-Term Treatments with Oral Chloroquine and Hydroxychloroquine in Patients with and without COVID-19: A Systematic Review.Pharmaceuticals (Basel, Switzerland) · 2022Review
- Nutritional risk of vitamin D, vitamin C, zinc, and selenium deficiency on risk and clinical outcomes of COVID-19: A narrative review.Clinical nutrition ESPEN · 2022Review
- Chloroquine drops against SARS-CoV-2 infection.The Indian journal of medical research · 2022Article
- Authors' response.The Indian journal of medical research · 2022Article
- Effects of hydroxychloroquine and favipiravir on clinical course in outpatients with COVID-19Turkish journal of medical sciences · 2021Article
- Efficacy of chloroquine and hydroxychloroquine for the treatment of hospitalized COVID-19 patients: a meta-analysis.Future virology · 2021Review
- Drug repurposing against SARS-CoV-1, SARS-CoV-2 and MERS-CoV.Future microbiology · 2021Article
- Structural deformability induced in proteins of potential interest associated with COVID-19 by binding of homologues present in ivermectin: Comparative study based in elastic networks models.Journal of molecular liquids · 2021Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
8 authors at 4 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundPopulations such as healthcare workers (HCW) that are unable to practice physical distancing are at high risk of acquiring Coronavirus disease-2019 (COVID-19). In these cases pharmacological prophylaxis would be a solution to reduce severe acute respiratory syndrome coronavirus-2 (SARS CoV-2) transmission. Hydroxychloroquine has in vitro antiviral properties against SARS CoV-2. We therefore sought to determine the efficacy and safety of hydroxychloroquine as prophylaxis for COVID-19. METHODS AND
findingsWe electronically searched EMBASE, MEDLINE, the Cochrane COVID-19 Register of Controlled Trials, Epistemonikos COVID-19, clinicaltrials.gov, and the World Health Organization International Clinical Trials Registry Platform up to September 28th, 2020 for randomized controlled trials (RCTs). We calculated pooled relative risks (RRs) for dichotomous outcomes with the corresponding 95% confidence intervals (CIs) using a random-effect model. We identified four RCTs (n = 4921) that met our eligibility criteria. The use of hydroxychloroquine, compared to placebo, did not reduce the risks of developing COVID-19 (RR 0.82, 95% CI 0.65 to 1.04, moderate certainty), hospitalization (RR 0.72, 95% CI 0.34 to 1.50, moderate certainty), or mortality (RR 3.26, 95% CI 0.13 to 79.74, low certainty), however, hydroxychloroquine use increased the risk of adverse events (RR 2.76, 95% CI 1.38 to 5.55, moderate certainty).
conclusionAlthough pharmacologic prophylaxis is an attractive preventive strategy against COVID-19, the current body of evidence failed to show clinical benefit for prophylactic hydroxychloroquine and showed a higher risk of adverse events when compared to placebo or no prophylaxis.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.