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Hydroxychloroquine in the Prevention of COVID-19 Infection in Healthcare Workers

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
ClinicalTrials.gov Identifier: NCT04333225
Recruitment Status : Completed
First Posted : April 3, 2020
Results First Posted : August 20, 2021
Last Update Posted : August 20, 2021
Information provided by (Responsible Party):
Baylor Research Institute

Brief Summary:
In order to assess the efficacy of hydroxychloroquine treatment weekly for a total of 7 weeks in the prevention of COVID-19 infection, three hundred sixty (360) Healthcare workers with high risk exposure to patients infected with COVID-19 will be tested for COVID-19 infection via nasopharyngeal (NP) swab once weekly for 7 weeks. Of those, one hundred eighty (180) will receive weekly doses of hydroxychloroquine for the duration of the study. Subjects who opt not to receive the study drug will form the control group.

Condition or disease Intervention/treatment Phase
COVID-19 Drug: Hydroxychloroquine Phase 2

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 221 participants
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Prevention
Official Title: A Prospective Clinical Study of Hydroxychloroquine in the Prevention of SARS- CoV-2 (COVID-19) Infection in Healthcare Workers After High-risk Exposures
Actual Study Start Date : April 3, 2020
Actual Primary Completion Date : June 30, 2020
Actual Study Completion Date : June 30, 2020

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Experimental: Hydroxychloroquine
Subjects who chose to enter the HCQ arm received a loading dose of 800 mg HCQ on day 1 followed by two 200 mg tablets once a week for a total of 7 weeks
Drug: Hydroxychloroquine
Weekly treatment in individuals at high risk
Other Names:
  • Plaquenil
  • HCQ

No Intervention: Control
Subjects who declined taking HCQ were considered as controls

Primary Outcome Measures :
  1. Number of Participants Infected With COVID-19 or COVID-19 Like Illness During the Trial [ Time Frame: Up to 7 weeks after study initiation ]
    Number of participants infected with COVID-19 or identified as having COVID-19 like illness during the trial

Secondary Outcome Measures :
  1. Time From Study Initiation Until the Occurrence of COVID-19 or COVID-19 Like Illness or Being Censored [ Time Frame: Up to 7 weeks after study initiation ]

    Time-to-first clinical event consisting of a persistent change for any of the following:

    • diagnosis of COVID-19
    • clinical characteristics of COVID-19 like illness
    • being censored

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 75 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  1. Adult male and female healthcare workers ≥ 18 to ≤ 75 years of age upon study consent
  2. Healthcare workers with

    • One day or more of exposure to suspect and/or positive COVID-19 patients, including but not limited to those working in the Emergency Department or Intensive Care Unit.


    • Unprotected exposure to a known positive COVID-19 patient within 72 hours of screening.

  3. Afebrile with no constitutional symptoms
  4. Willing and able to comply with scheduled visits, treatment plan, and other study procedures
  5. Evidence of a personally signed and dated informed consent document indicating that the subject (or a legally acceptable representative) has been informed of all pertinent aspects of the study prior to initiation of any subject-mandated procedures

Exclusion Criteria:

  1. Participation in other investigational clinical trials for the treatment or prevention of SARS-COV-2 infection within 30days
  2. Unwilling to practice acceptable methods of birth control (both males who have partners of childbearing potential and females of childbearing potential) during Screening, while taking study drug, and for at least 30 days after the last dose of study drug is ingested Note: the following criteria follow standard clinical practice for FDA approved indications of this medication
  3. Having a prior history of blood disorders such as aplastic anemia, agranulocytosis, leukopenia, or thrombocytopenia
  4. Having a prior history of glucose-6-phosphate dehydrogenase (G-6-PD) deficiency
  5. Having dermatitis, psoriasis or porphyria
  6. Taking Digoxin, Mefloquine, methotrexate, cyclosporine, praziquantel, antacids and kaolin, cimetidine, ampicillin, Insulin or antidiabetic drugs, arrhythmogenic drugs, antiepileptic drugs, loop, thiazide, and related diuretics, laxatives and enemas, amphotericin B, high dose corticosteroids, and proton pump inhibitors, neostigmine, praziquantel, Pyridostigmine, tamoxifen citrate
  7. Allergies: 4-Aminoquinolines
  8. Pre-existing retinopathy of the eye
  9. Has a chronic liver disease or cirrhosis, including hepatitis B and/or untreated hepatitis
  10. Untreated or uncontrolled active bacterial, fungal infection
  11. Known or suspected active drug or alcohol abuse, per investigator judgment
  12. Women who are pregnant or breastfeeding
  13. Known hypersensitivity to any component of the study drug
  14. A known history of prolonged QT syndrome or history of additional risk factors for torsades de pointe (e.g., heart failure, requires a lab test , family history of Long QT Syndrome), or the use of concomitant medications that prolong the QT/QTc interval

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04333225

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United States, Texas
Baylor University Medical Center
Dallas, Texas, United States, 75226
Sponsors and Collaborators
Baylor Research Institute
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Principal Investigator: Peter A McCullough, MD, MPH Baylor Health Care System
  Study Documents (Full-Text)

Documents provided by Baylor Research Institute:
Study Protocol  [PDF] May 28, 2020
Statistical Analysis Plan  [PDF] May 28, 2020

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Responsible Party: Baylor Research Institute
ClinicalTrials.gov Identifier: NCT04333225    
Other Study ID Numbers: 020-132
First Posted: April 3, 2020    Key Record Dates
Results First Posted: August 20, 2021
Last Update Posted: August 20, 2021
Last Verified: May 2020
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: Yes
Studies a U.S. FDA-regulated Device Product: No
Product Manufactured in and Exported from the U.S.: No
Keywords provided by Baylor Research Institute:
Additional relevant MeSH terms:
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Respiratory Tract Infections
Pneumonia, Viral
Virus Diseases
Coronavirus Infections
Coronaviridae Infections
Nidovirales Infections
RNA Virus Infections
Lung Diseases
Respiratory Tract Diseases
Antiprotozoal Agents
Antiparasitic Agents
Anti-Infective Agents
Enzyme Inhibitors
Molecular Mechanisms of Pharmacological Action
Antirheumatic Agents