Trial · NCT04328961
Hydroxychloroquine for COVID-19 Post-exposure Prophylaxis (PEP)
NCT04328961, Phase 2, Phase 3, Completed, University of Washington; results first posted 2021-12-16
3 sourcestrials-2026-11-12-0.5.0
Cite this record
ConductScience Library. Hydroxychloroquine for COVID-19 Post-exposure Prophylaxis (PEP). Trials, record NCT04328961. Release trials-2026-11-12-0.5.0, 12 Nov 2026. https://conductscience.org/library/trials/NCT04328961
On this page
Trial
As registered on ClinicalTrials.gov, in the graph's capture of the registry.
- Title
- Hydroxychloroquine for COVID-19 Post-exposure Prophylaxis (PEP)
- NCT number
- NCT04328961
- Status
- Completed
- Phases
- Phase 2, Phase 3
- Enrollment
- 943 participants, actual
- Lead sponsor
- University of Washington
- Conditions
- COVID-19, Corona Virus Infection, SARS (Severe Acute Respiratory Syndrome), SARS-CoV-2
- Interventions
- Hydroxychloroquine Sulfate, Ascorbic Acid
- First posted
- 2020-04-01
- Last updated
- 2021-12-16
- Results first posted
- 2021-12-16
Source ClinicalTrials.gov
Registered outcomes4
Each outcome the trial registered, primary first, in ClinicalTrials.gov's words.
| List | Outcome | Time frame | Description |
|---|---|---|---|
| Primary | Number of Participants Who Had Polymerase Chain Reaction (PCR) Confirmed SARS-CoV-2 Infection | Day 1 through Day 14 after enrolment | Polymerase chain reaction (PCR) confirmed severe acute respiratory syndrome coronavirus 2 of the genus Betacoronavirus (SARS-CoV-2) infection from self-collected samples collected daily for 14 days |
| Primary | The Number of Participants Who Had Polymerase Chain Reaction (PCR) Confirmed SARS-CoV-2 Infection | Day 28 after enrolment | Polymerase chain reaction (PCR) confirmed SARS-CoV-2 infection from self-collected samples collected at study exit |
| Secondary | Rate of Participant-reported Adverse Events | 28 days from start of Hydroxychloroquine therapy | Safety and tolerability of Hydroxychloroquine as SARS-CoV-2 PEP in adults |
| Secondary | Number of Participants Who Had COVID-19 Disease | 28 days from enrolment | Participants who had a PCR-confirmed SARS-CoV-2 infection and met the Center for Disease Control (CDC) defined criteria for symptomatic COVID-19 disease. |
Source ClinicalTrials.gov
Outcomes4
Each outcome the trial posted results for, in ClinicalTrials.gov's words.
| Type | Outcome | Time frame | Population | Units | Measured as |
|---|---|---|---|---|---|
| PRIMARY | Number of Participants Who Had Polymerase Chain Reaction (PCR) Confirmed SARS-CoV-2 Infection | Day 1 through Day 14 after enrolment | The above participants qualified for the Modified Intention-to-Treat Cohort | Participants | COUNT_OF_PARTICIPANTS |
| PRIMARY | The Number of Participants Who Had Polymerase Chain Reaction (PCR) Confirmed SARS-CoV-2 Infection | Day 28 after enrolment | Participants | COUNT_OF_PARTICIPANTS | |
| SECONDARY | Rate of Participant-reported Adverse Events | 28 days from start of Hydroxychloroquine therapy | Participants | COUNT_OF_PARTICIPANTS | |
| SECONDARY | Number of Participants Who Had COVID-19 Disease | 28 days from enrolment | Participants | COUNT_OF_PARTICIPANTS |
Source ClinicalTrials.gov
Results by group8
Each measurement the trial posted, group by group, in the words and numbers it posted.
| Outcome | Group | Category | Value | Spread | Units |
|---|---|---|---|---|---|
| Number of Participants Who Had Polymerase Chain Reaction (PCR) Confirmed SARS-CoV-2 Infection | Ascorbic Acid | 45 | Participants | ||
| Number of Participants Who Had Polymerase Chain Reaction (PCR) Confirmed SARS-CoV-2 Infection | Hydroxychloroquine | 53 | Participants | ||
| The Number of Participants Who Had Polymerase Chain Reaction (PCR) Confirmed SARS-CoV-2 Infection | Ascorbic Acid | 48 | Participants | ||
| The Number of Participants Who Had Polymerase Chain Reaction (PCR) Confirmed SARS-CoV-2 Infection | Hydroxychloroquine | 58 | Participants | ||
| Rate of Participant-reported Adverse Events | Ascorbic Acid | 46 | Participants | ||
| Rate of Participant-reported Adverse Events | Hydroxychloroquine | 66 | Participants | ||
| Number of Participants Who Had COVID-19 Disease | Ascorbic Acid | 26 | Participants | ||
| Number of Participants Who Had COVID-19 Disease | Hydroxychloroquine | 37 | Participants |
Source ClinicalTrials.gov
Participant flow6
How many started, completed or left each group, period by period.
| Period | Milestone | Group | Participants | Units counted |
|---|---|---|---|---|
| Overall Study | STARTED | Ascorbic Acid | 422 | |
| Overall Study | STARTED | Hydroxychloroquine | 407 | |
| Overall Study | COMPLETED | Ascorbic Acid | 336 | |
| Overall Study | COMPLETED | Hydroxychloroquine | 353 | |
| Overall Study | NOT COMPLETED | Ascorbic Acid | 86 | |
| Overall Study | NOT COMPLETED | Hydroxychloroquine | 54 |
Source ClinicalTrials.gov
Adverse events26
Each adverse event the trial posted, group by group: the participants affected out of those at risk.
| Type | Event | Organ system | Group | Affected | At risk | Events |
|---|---|---|---|---|---|---|
| other | Diarrhea, abdominal discomfort, or vomiting | Gastrointestinal disorders | Ascorbic Acid | 7 | 422 | 7 |
| other | Diarrhea, abdominal discomfort, or vomiting | Gastrointestinal disorders | Hydroxychloroquine | 25 | 407 | 25 |
| other | Nausea or upset stomach | Gastrointestinal disorders | Ascorbic Acid | 10 | 422 | 10 |
| other | Nausea or upset stomach | Gastrointestinal disorders | Hydroxychloroquine | 14 | 407 | 14 |
| other | Skin reaction/rash | Skin and subcutaneous tissue disorders | Ascorbic Acid | 8 | 422 | 8 |
| other | Skin reaction/rash | Skin and subcutaneous tissue disorders | Hydroxychloroquine | 11 | 407 | 11 |
| other | Neurologic reaction: irritability, dizziness, or vertifgo | General disorders | Ascorbic Acid | 11 | 422 | 11 |
| other | Neurologic reaction: irritability, dizziness, or vertifgo | General disorders | Hydroxychloroquine | 6 | 407 | 6 |
| other | Headache | General disorders | Ascorbic Acid | 7 | 422 | 7 |
| other | Headache | General disorders | Hydroxychloroquine | 5 | 407 | 5 |
1 to 10 of 26Source ClinicalTrials.gov
See all 26 adverse eventsAdverse event totals6
The totals the trial posted for each group.
| Total | Group | Affected | At risk |
|---|---|---|---|
| Total, all-cause mortality | Ascorbic Acid | 0 | 422 |
| Total, all-cause mortality | Hydroxychloroquine | 0 | 407 |
| Total, other adverse events | Ascorbic Acid | 46 | 422 |
| Total, other adverse events | Hydroxychloroquine | 66 | 407 |
| Total, serious adverse events | Ascorbic Acid | 2 | 422 |
| Total, serious adverse events | Hydroxychloroquine | 2 | 407 |
Source ClinicalTrials.gov
Papers2
The papers the trial lists on ClinicalTrials.gov.
Grants0
The grants NIH RePORTER links to the trial, newest funded first: NIH's, and some of AHRQ's, CDC's, FDA's and VA's. Each shows its title, principal investigators, organization and funder in its newest year.
None in this release.
Trial comparisons6
Comparisons of the trial's two groups, calculated by ConductScience from the counts it posted.
| Comparison | Source |
|---|---|
| Ascorbic Acid vs Hydroxychloroquine: Rate of Participant-reported Adverse Events | Trial comparisons |
| Ascorbic Acid vs Hydroxychloroquine: Number of Participants Who Had Polymerase Chain Reaction (PCR) Confirmed SARS-CoV-2 Infection | Trial comparisons |
| Ascorbic Acid vs Hydroxychloroquine: Number of Participants Who Had COVID-19 Disease | Trial comparisons |
| Ascorbic Acid vs Hydroxychloroquine: The Number of Participants Who Had Polymerase Chain Reaction (PCR) Confirmed SARS-CoV-2 Infection | Trial comparisons |
| Ascorbic Acid vs Hydroxychloroquine: deaths from any cause | Trial comparisons |
| Ascorbic Acid vs Hydroxychloroquine: serious adverse events | Trial comparisons |
Tests0
The ConductCognition tests this trial's registered outcomes name, as ScienceGraph matched them in trial-tests-2026-11-12-0.2.1.
None in this release.
Data dates
The day each source was copied for this release.
Sources 3
- ClinicalTrials.gov's posted results, through CTTI's AACTFreely available. Acknowledgement requested
- ClinicalTrials.govNo license stated
- NIH RePORTER's clinical studies and project filesPublic domain
Each source's terms
- ClinicalTrials.gov's posted results, through CTTI's AACTClinicalTrials.gov data via Aggregate Analysis of ClinicalTrials.gov (AACT), CTTI. CTTI makes its materials freely available and requests acknowledgement. https://aact.ctti-clinicaltrials.org/documentation/299
- ClinicalTrials.govnone stated
- NIH RePORTER's clinical studies and project filesPublic domain (NIH RePORTER)
ClinicalTrials.gov's data carry an international copyright outside the United States: https://clinicaltrials.gov/about-site/terms-conditions.
For software
Read this trial from software.
The record and each of its lists are JSON, twenty rows a page. No key.
GET https://conductscience.org/api/trials/v1/NCT04328961
GET https://conductscience.org/api/trials/v1/NCT04328961/events?page=2