for people ages 18 years and up (full criteria)
at Sacramento, California and other locations
study started



ORCHID is a multicenter, blinded, placebo-controlled, randomized clinical trial evaluating hydroxychloroquine for the treatment of adults hospitalized with COVID-19. Patients, treating clinicians, and study personnel will all be blinded to study group assignment.

Official Title

Outcomes Related to COVID-19 Treated With Hydroxychloroquine Among In-patients With Symptomatic Disease


Effective therapies for COVID-19 are urgently needed. Hydroxychloroquine is an antimicrobial agent with immunomodulatory and antiviral properties that has demonstrated in vitro activity against SARS-CoV-2, the virus that causes COVID-19. Preliminary reports suggest potential efficacy in small human studies. Clinical trial data are needed to determine whether hydroxychloroquine is effective in treating COVID-19.

Study Aim: To compare the effect of hydroxychloroquine versus placebo on clinical outcomes, measured using the COVID Ordinal Outcomes Scale at Day 15, among adults with COVID-19 requiring hospitalization.

Study Hypothesis: Among adults hospitalized with COVID-19, administration of hydroxychloroquine will improve clinical outcomes at Day 15.



Coronavirus Acute Respiratory Infection SARS-CoV Infection COVID-19 Infection Communicable Diseases Respiratory Tract Infections Coronavirus Infections Severe Acute Respiratory Syndrome Hydroxychloroquine Hydroxychlorquine


You can join if…

Open to people ages 18 years and up

  1. Age ≥18 years
  2. Currently hospitalized or in an emergency department with anticipated hospitalization.
  3. Symptoms of acute respiratory infection, defined as one or more of the following:
  4. cough
  5. fever (> 37.5° C / 99.5° F)
  6. shortness of breath (operationalized as any of the following: subjective shortness of breath reported by patient or surrogate; tachypnea with respiratory rate ≥22 /minute; hypoxemia, defined as SpO2 <92% on room air, new receipt of supplemental oxygen to maintain SpO2 ≥92%, or increased supplemental oxygen to maintain SpO2 ≥92% for a patient on chronic oxygen therapy).
  7. sore throat
  8. Laboratory-confirmed SARS-CoV-2 infection within the past 10 days prior to randomization.

You CAN'T join if...

  1. Prisoner
  2. Pregnancy
  3. Breast feeding
  4. Symptoms of acute respiratory infection for >10 days before randomization
  5. >48 hours between meeting inclusion criteria and randomization
  6. Seizure disorder
  7. Porphyria cutanea tarda
  8. Diagnosis of Long QT syndrome
  9. QTc >500 ms on electrocardiogram within 72 hours prior to enrollment
  10. . Known allergy to hydroxychloroquine, chloroquine, or amodiaquine
  11. . Receipt in the 12 hours prior to enrollment, or planned administration during the 5-day study period that treating clinicians feel cannot be substituted for another medication, of any of the following: amiodarone; cimetidine; dofetilide; phenobarbital; phenytoin; sotalol
  12. . Receipt of >1 dose of hydroxychloroquine or chloroquine in the 10 days prior to enrollment
  13. . Inability to receive enteral medications
  14. . Refusal or inability to be contacted on Day 15 for clinical outcome assessment if discharged prior to day 15
  15. . Previous enrollment in this trial
  16. . The treating clinical team does not believe equipoise exists regarding the use of hydroxychloroquine for the treatment of this patient


  • UC Davis Medical Center
    Sacramento California 95817 United States
  • UCSF Medical Center
    San Francisco California 94143 United States


accepting new patients
Start Date
Completion Date
Massachusetts General Hospital
Website for the PETAL Network Sign up for this study
Phase 3
Study Type
Last Updated