COVID-19 Scientific Advisory Group Rapid Response Report

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COVID-19 Scientific Advisory Group Rapid
                 Response Report

Key Research Question:

What is the evidence for and risks of using hydroxychloroquine (HQ) as a
treatment and prophylaxis for SARS-CoV-2? [Updated April 16, 2020]

Context
   •   There is widespread concern of contracting the virus that causes COVID-19 among
       both the public and among health care workers.
   •   HQ has been suggested as treatment and prophylaxis for COVID-19 illness in social
       media, news reports, some scientific data and announcements from politicians.
   •   In Alberta, there have been anecdotal reports of physicians prescribing HQ for their
       colleagues or staff. This has prompted an advisory from the Alberta College of
       Pharmacy for their members not to dispense HQ when stockpiling is suspected
       (Alberta College of Pharmacy, March, 2020). A similar advisory was sent from the
       College of Physicians and Surgeons of Alberta to its members (April 2020).
   •   There is ongoing controversy about the role of HQ in the treatment of COVID with
       evolving signals of potential harm in COVID-19 patients. Recommendations that HQ
       be taken off order sets for COVID management in AHS outside the setting of
       monitored randomized controlled trials have been made to reflect changes to major
       national guidelines (Association of Medical Microbiology and Infectious Diseases
       Canada, Infectious Diseases Society of America, American Thoracic Society) in
       Canada and the US.

Key Messages from the Evidence Summary
   •   The evidence of HQ effectiveness in treating COVID-19 illness is limited. Although there
       is plausible in vitro activity of HQ against COVID-19, there is equivocal in vivo data
       across observational studies and small randomized controlled trials with significant
       methodologic concerns.
   •   There is no evidence for HQ for use as prophylaxis for COVID-19 illness. There are
       multiple randomized trials underway to explore this in health care workers and close
       contacts to known cases.
   •   HQ risks, particularly when used for patients with cardiopulmonary compromise due to
       COVID-19 infection, include the potential for serious clinical and laboratory adverse
       effects, potential drug interactions, and carry a risk to children if unintentionally ingested.

Committee Discussion
The committee recommended prioritizing use of HQ for patients with rheumatologic disease,
and those in COVID-19 randomized controlled clinical trials and recommended removing HQ
from COVID-19 order sets. The committee felt strongly that any off-label use of HQ requires the
prescribers’ careful consideration of risk/benefit, consultation between experts and attending
physicians, and documenting a verbal consent from patients after discussion of the current state

                                  © 2020, Alberta Health Services,
                                 COVID-19 Scientific Advisory Group                              April 16, 2020
Hydroxychloroquine as treatment/prophylaxis for COVID-19 • 2

of evidence of benefit and harms. This reflects the content of an Ethics consult that was done in
the context of this review. Committee members noted that if used outside the context of clinical
trials, adverse events of HQ for hospitalized patients should be documented/collected by
clinicians through the AHS Reporting and Learning System for Patient Safety at
https://insite.albertahealthservices.ca/tools/rls/Page1820.aspx. One committee member felt
strongly that HQ should not be used outside the context of a clinical trial. It was noted that the
HOPE Alberta COVID trial is collecting information on the safety of HQ at 7 and 30 days in trial
participants.

There were concerns raised by the Divisions of Infectious Diseases regarding continuation of
the recommendation for mandatory Infectious Disease (ID) consult or approval, because of the
variation in opinion of ID physicians on off label investigational therapies in COVID-positive
patients. Therefore, we recommend to remove this from the existing process and instead leave
it as an option on a case by case basis reflecting usual clinical considerations. Since an option
of using HQ for hospitalized patients will still exist, it is important to prescribers to determine the
risk of adverse events prior to initiation. This includes ensuring physicians are aware of and
mitigate the risk of prolonged QTc (including ordering baseline ECG, and assessing drug
interactions with patient’s existing medications) and hypoglycemia. Pharmacy Services will be in
a position to assist with the drug interaction check. The committee also felt that the additional
safety concerns that exist for azithromycin and HQ, while specifically note in literature because
these have been recommended for COVID19 in the past, are similar for all macrolides as the
QTc prolongation is a class effect (i.e. same would happen with clarithromycin or erythromycin).

With respect to prophylaxis, there was agreement with the recommendation to restrict use of
HQ for prophylaxis to only within clinical trials as there is no existing evidence to support benefit,
and there are concerns with increased household use of hydroxychloroquine given concerns
around risk and toxicity to children who might unintentionally access this within the home
setting.

Recommendations
   1. Hydroxychloroquine is not currently recommended to be used as prophylaxis for COVID-
      19 outside clinical trials, given the lack of established benefit to counterbalance potential
      harms, and no existing data on prophylaxis.
   2. Given the significant increased risk of QT prolongation and cardiac arrhythmias, HQ
      should not be used with azithromycin or other macrolide antibiotics unless in the context
      of a clinical trial. These medications should also not be used sequentially given very long
      half-lives and continued QT prolongation risk.
   3. As there are limited supplies of hydroxychloroquine within AHS, and concerns may
      eventually arise with supply in Alberta’s community pharmacies, its use should be
      prioritized to those patients who are on it for chronic rheumatologic conditions, where
      there is stronger evidence of benefit.
Hydroxychloroquine as treatment/prophylaxis for COVID-19 • 3

   4. For patients with COVID-19 disease, in both the hospital and the community, preference
      for use of HQ as treatment is given to those enrolled in clinical trials investigating the
      effects of HQ in treating and preventing severe COVID-19 illness.
   5. Off-label prescribing of hydroxychloroquine for treatment of COVID-19 positive inpatients
      should only be performed after careful consideration of the potential harms,
      consideration of expert consultation as needed (e.g., Infectious Disease, Respiratory
      Medicine, and General Internal Medicine) and discussion between the Most Responsible
      Physician and the patient.
   6. If all criteria in #5 are met and the decision is made to use HQ:
           a. The use of a risk stratification tool (e.g. Tisdale et al, 2013) to access the risk of
                QTc prolongation must be considered when evaluating the benefit vs harm of
                using HQ as treatment in SARS-CoV-2 patients.
           b. A drug interaction check between HQ and the patient’s medications must be
                completed using the website https://www.covid19-druginteractions.org/ or a
                suitable alternative. Pharmacy Services can assist with performing the drug
                interaction check.
           c. While the patient is on HQ, baseline and intermittent ECGs to assess the
                corrected QT (QTc) interval during treatment should be considered depending on
                the patient’s baseline risk.
           d. Adverse events with respect to off-label use of HQ for inpatient treatment should
                be documented and reported by clinicians through the AHS Reporting and
                Learning System for Patient Safety at
                https://insite.albertahealthservices.ca/tools/rls/Page1820.aspx.
           e. These recommendations will be updated as the published data evolves.

Summary of Evidence
Literature for this rapid review was gathered in a search strategy performed by Knowledge
Resource Services (KRS) in AHS, pulling from a pragmatic search of the COVID-19 literature,
as well as through medication safety sources (e.g.: LexiComp). Limitations to this review are the
lack of available scientific peer reviewed evidence on this topic for COVID-19 and there may be
evidence from the SARS and MERS experience that was missed by this strategy. A total of 61
references were included in this review. Inclusion/exclusion criteria can be found in the
Appendix.

What is the evidence that HQ is effective as a treatment for COVID-19?
In Vitro
Both chloroquine (CQ) and HQ have been shown in vitro to inhibit the growth of coronavirus
(Keyaerts et al., 2004; Liu J et al, 2020; Vincent et al., 2005; Kono et al., 2008; Yao et al., 2020;
Wang et al., 2020). Yao (2020) and Wang (2020) are already referenced in the Alberta Health
Services (AHS) antimicrobial recommendations document (AHS, 2020). In summary, in vitro
studies show a plausible role of HQ in the treatment of SARS-CoV-2.
Hydroxychloroquine as treatment/prophylaxis for COVID-19 • 4

In Vivo
In vivo studies in mice have also shown that CQ improves survivability in mice infected with
human coronavirus (Keyaerts et al., 2009). With respect to human studies, the first clinical trial
data became available mid-March from an open label nonrandomized trial, looking at the
efficacy of 600 milligrams of hydroxychloroquine twice a day (plus/minus azithromycin) in
reducing nasal swab viral burden by polymerase chain reaction (PCR) positivity in a cohort of 20
patients. At days 3 and 6 post-therapy, PCR was negative in 50% and 70% of the treated
patients, respectively, compared to 6.3% and 12.5% in the untreated group (Gautret et al.,
2020a). No clinical outcomes were reported, and patients with severe illness in the HQ arm
were censored from the data after ICU admission. A small pilot randomized controlled trial in
China (n=30) showed no difference in virologic or clinical patterns between HQ treated and
untreated patients (Chen J, et al, 2020). A preprint randomized parallel-group trial of 62 patients
reported that patients in the treatment arm (5-day HQ 200mg b.i.d.) had a significantly
shortened body temperature recovery time (3.2 days [1.3 SD] vs 2.2 days [0.4 SD]; p=.0008])
and cough remission time (3.15 days [1.5 SD] vs 2.0 days [0.2]; p=.0016) and improved
pneumonia (80.6% vs 54.8%) (Chen Z et al, 2020). Notably, the original trial registered for this
study included a sample size of 100 per group, with only 31 patients per group being reported
(Chinese Clinical Trial Registry (ChiCTR), identifier: ChiCTR2000029559).
In summary, these studies provide some preliminary evidence that HQ may be effective in
treatment of COVID-19; however, severe limitations and criticism of the Gautret et al (2020a)
study are well known (Dahly D, Gates S & Morris T, 2020; Frie, K, & Gbinigie K, 2020; Kim et al,
2020; Lowe D, 2020; Retraction Watch, 2020; Yazdany & Kim 2020), and the Chen study was
underpowered. Thus further evolution of this evidence is required.
Current State of Recommendations in Other Jurisdictions
Recommendations for the use of CQ/HQ in SARS-CoV-2 patients have been released
beginning in China with respect to pulmonary disease (Dong et al., 2020, Gao J, Tian Z & Yang
X, 2020; Liang et al., 2020) but there are recommendations in support of its use available
internationally, including an Emergency Use Authorization issued by the US FDA on March 28,
2020 (Hinton, 2020, US FDA 2020a; US FDA 2020b). To date, recommendations are based on
these in vitro data, limited and weak human studies and physician opinion rather than on clinical
trial evidence. As such, recommendations for the use of HQ in SARS-CoV-2 patients would
have to be made in the absence of high-quality clinical trial evidence at this time. Recently
released guidelines for COVID-19 therapy from the Infectious Diseases Society of
America,(IDSA, 2020) using the Grading of Recommendations Assessment, Development and
Evaluation (GRADE) approach concluded that the currently available best evidence failed to
demonstrate or exclude a beneficial effect of HQ on the clinical progression of COVID-19, noting
that current trails assess only indirect outcomes. Very high risk selection bias was noted in the
virologic outcomes described fro HQ plus azithromycin use. Two studies described significant
QT prolongation in 10 of 95 patients (Chorin et al, 2020; Molina et al, 2020).
What is the evidence that HQ is effective as a prophylaxis for COVID-19?
As of April 13, 2020, there are no available data from randomized clinical trials, cohort or
observational studies to inform clinical guidance on the use, dosing, or duration of CQ or HQ for
Hydroxychloroquine as treatment/prophylaxis for COVID-19 • 5

prophylaxis of SARS-CoV-2 infection (Clinicaltrials.gov, 2020). A document circulating on
Twitter indicates that HQ is being used for COVID-19 prophylaxis in India, using its purported
benefits as a treatment as the rationale for prophylaxis (Bargahva, 2020). There is insufficient
evidence on the effectiveness of HQ as a prophylactic for COVID-19.
What are the risks of using HQ as prophylaxis or as treatment for COVID-19?
In addition to the fact that RCTs are lacking, making it difficult to quantify risks in this specific
uninfected population, the risks for HQ prophylaxis for SARS-CoV-2 include the following:
    1. Acute adverse effects may include serious clinical and laboratory features, including
       prolonged QTc and hypoglycemia.
    2. Multiple potential drug interactions with patient’s therapeutic medications.
    3. Risk of pediatric morbidity and mortality with increased unintentional exposures in the
       home if used widely for prophylaxis.
Safety considerations for the use of CQ, HQ and AZM and other macrolide antibiotics in the
management of SARS-CoV-2 infections identified the potential risks of treatment using CQ/HQ
to include QTc prolongation (Chorlin et al, 2020), particularly in patients with pre-existing cardiac
disease or if used in combination with AZM, as well as other known risks associated with these
drugs including hypoglycemia (Unübol M et al, 2011), drug-drug interactions (Somer M et al,
2000) and neuropsychiatric effects (Bhatia 1991; Das P et al, 2014). Evidence of adverse
events is now available, including a preprint retrospective study that reported significant QTc
prolongation (p500ms (Chorin, E et al, 2020). In this study, both baseline QTc and
QTc >460ms were not reliable predictors of extreme QTc prolongation in this preliminary work.
Risk of pediatric morbidity and mortality with unintentional exposures is also concerning (Smith
& Klein-Schwartz, 2005).
With respect to CQ, a parallel, double-blind randomized trial in Brazil on CQ as treatment for
SARS-CoV-2 was required to shut down recruitment to the high dose arm (CQ 600mg b.i.d. for
10 days (total CQ=12g) due to fatal cardiac complications (13.5%) (Silva Borba et al, 2020).

How stable is the supply of HQ to Alberta?
HQ is an oral tablet is offered by four manufacturers in Canada. Overall there is a commitment
to ensure continued supply at historical rates to ensure continued access for patients on HQ for
other conditions (e.g., systemic lupus erythematosus, rheumatoid arthritis). With the worldwide
focus on HQ use in COVID-19, it is anticipated that supplies beyond historical use will be limited
and inappropriate use will result in reduced access for patients with chronic rheumatologic
conditions such as lupus and rheumatoid arthritis that require ongoing maintenance therapy.
While AHS can directly assess its current HQ stock, this is not possible for community
pharmacies.
Hydroxychloroquine as treatment/prophylaxis for COVID-19 • 6

Evolving Evidence
The evidence for these research questions is rapidly evolving. There are several clinical trials
underway investigating the prophylactic and treatment effectiveness of HQ. This review will be
updated as new data from additional trials is made available. It will be important to be able to
assess the quality and outcomes of these upcoming human clinical trials to understand the
efficacy of HQ in COVID-19.

 Date question received by advisory group: 24 March 2020
 Date report submitted to committee: 26 March 2020
 Date of first assessment: 25 March 2020
 Date of re-assessment: April 16, 2020

Authorship & Committee Members
This review was updated by Jamie Boyd and scientifically reviewed by Mark Yarema (external
reviewer), Braden Manns (co-chair), and Riley Hartmann (external reviewer). The full Scientific
Advisory Group was involved in discussion and revision of the document: Lynora Saxinger (co-
chair), John Conly, Alexander Doroshenko, Shelley Duggan, Nelson Lee, Elizabeth MacKay,
Andrew McRae, Jeremy Slobodan, James Talbot, Brandie Walker, and Nathan Zelyas.

© 2020, Alberta Health Services, COVID-19 Scientific Advisory Group

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COVID-19 Scientific Advisory Group Rapid
               Response Report

Appendix

List of non-clinical abbreviations
AHS: Alberta Health Services
AZM: Azithromycin
CalHR: Calibrated hazard ratio
CQ: Chloroquine
CIOMS: Council for International Organizations of Medical Sciences
HQ: Hydroxychloroquine
RCT: randomized controlled trial

Inclusion and Exclusion Criteria for Studies Eligible for Data Extraction
 Inclusion*                                      Exclusion
 • HQ as treatment or prophylactic for           • SARS or MERS studies
     COVID-19                                    • Describes basic findings without
 • Describes clinical or public health              application to clinical or public health
     application of HQ for COVID-19                 context
 • Describes coordination of research efforts • No outcomes described
     for use of HQ in COVID-19 cases             • Influenza, RSV, circulating coronavirus, or
 • Describes outcomes of HQ-based therapy           other contagious virus
     for COVID-19
 • Human or animal studies (in vivo/ in vitro)
 • Any population
 • SARS-CoV-2 (COVID-19)
 • Any jurisdiction
 • Guidelines
 • Article is peer-reviewed, is from a
     reputable source, or has a described
     methodology (includes letters, abstracts,
     reviews)
* Letters to the editor and commentaries were reviewed for primary sources.

Evidence Review
Literature for this rapid review was gathered in a search strategy performed by Knowledge
Resource Services (KRS) in AHS, pulling from personal literature libraries and a pragmatic
search of the COVID-19 literature. This is an important limitation of this review, as there may be

                                  © 2020, Alberta Health Services,
                                 COVID-19 Scientific Advisory Group                           April 16, 2020
Hydroxychloroquine as treatment/prophylaxis for COVID-19 • 8

evidence from the SARS and MERS experience that was missed by this strategy. The review is
also limited by the lack of available COVID-19 evidence. A total of 61 references were included
in this review. Inclusion/exclusion criteria can be found in the Appendix.
What is the evidence that HQ is effective as a treatment for COVID-19?
Findings from previous in vitro studies on a different corona virus, SARS-CoV, have suggested
that chloroquine and hydroxychloroquine may inhibit the coronavirus through a series of steps.
The drugs can inhibit glycosylation of the ACE2 receptor required for viral fusion to the cell
membrane (Vincent et al, 2005). Additionally, it can change the pH of endosomes, causing
further interference with cell fusion, along with inhibition of nucleic acid replication, glycosylation
of viral proteins, virus assembly, new virus particle transport, virus release to achieve its antiviral
effects.
In Vitro
There are in vitro studies for the use of CQ and HQ to inhibit SARS-CoV-2, such as Wang et al
(2020) reporting that CQ in vitro showed antiviral activity in simian kidney cells at dosages and
concentrations typical of chronic rheumatoid arthritis patients (Mackenzie, 1983). Lui et al
(2020) reported that both CQ and HQ were potent compounds against viral particles finding
comparable 50% cytotoxic concentration, with CQ having a lower 50% maximal effect than HQ.
Whereas Yao and colleagues (2020) reported that HQ was stronger than CQ in vitro. The
authors used in vitro data and theoretical physiologically based pharmacokinetic models to
predict that these molecules will work in humans at the recommended dose. These two in vitro
studies (Yao et al, 2020; Wang et al, 2020) are already referenced within the AHS COVID-19
antimicrobial recommendations document (AHS, 2020).
A Belgian study demonstrated that CQ demonstrated both antiviral and cytostatic activity in
SARS-CoV-cultured cells (Keyaerts et al, 2004), which was also demonstrated in a study from
the United States (Vincent et al, 2005). Vincent et al. also commented that CQ was effective
both before and after the cells were cultured with the virus, and suggested a potential role for
CQ in prophylaxis. One Japanese study also demonstrated CQ’s ability to inhibit viral replication
in human coronavirus 229E-infected cells (Kono et al, 2008).
In Vivo
There is one animal study from Belgium that demonstrated that CQ improved survival in mice
infected with human coronavirus OC43 (Keyaerts et al, 2009).
Human trials
With respect to human trials, the first clinical trial data became available mid-March from an
open label nonrandomized trial was published looking at the efficacy of 600 milligrams of
hydroxychloroquine twice a day (plus azithromycin) in reducing nasal swab polymerase chain
reaction (PCR) positivity in a cohort of 20 patients (Gautret et al, 2020a). At days 3 and 6 post-
therapy, PCR was negative in 50% and 70% of the treated patients, respectively, compared to
6.3% and 12.5% in the untreated group (Gautret et al., 2020a). No clinical outcomes were
reported, and patients with severe illness in the HQ arm were censored from the data after ICU
admission. This study has been widely criticized including lack of randomization, handling of
Hydroxychloroquine as treatment/prophylaxis for COVID-19 • 9

patients lost to follow-up (patients excluded without intention to treat analysis), insufficient
sample size to reach 85% power and absence of clinical outcomes reported (Dahly D, Gates S
& Morris T, 2020; Frie, K, & Gbinigie K, 2020; Kim et al, 2020; Lowe D, 2020; Retraction Watch,
2020; Yazdany & Kim 2020). The results of this study built upon a February 2020 news briefing
from China that reported clinical results in 100 patients showing reduced duration of illness and
significant improvement in CT imaging following treatment with chloroquine phosphate, with no
adverse events reported (Gao J, Tian Z & Yang X, 2020). Importantly, these findings seem to be
a combination of ongoing clinical trials with varied study design and, to date, there is no
empirical evidence available to confirm these findings.
Other human trials include a small pilot randomized controlled trial in China (n=30) which
showed no difference in virologic or clinical patterns between HQ treated and untreated patients
(Chen J, et al, 2020). A small, preprint randomized parallel-group trial of 62 patients with SARS-
CoV-2 and chest CT confirming pneumonia found that, compared to the control group, the 31
patients in the HQ treatment arm (5-day HQ 200mg b.i.d) showed a significantly shortened body
temperature recovery time (3.2 days [1.3 SD] vs 2.2 days [0.4 SD]; p=.0008]) and cough
remission time (3.15 days [1.5 SD] vs 2.0 days [0.2]; p=.0016), with a larger CT improvement
seen in the treatment arm compared to the control arm (80.6% vs 54.8%, respectively) (Chen Z
et al, 2020). Patients with any cardiac arrhythmia were excluded. 4 patients in the control group
progressed to severe illness. In the treatment group, 2 patients experienced mild adverse
effects (1 headache, 1 rash). Notably, the original trial registered for this study included a
sample size of 100 per group, with only 31 patients per group being reported (Chinese Clinical
Trial Registry (ChiCTR), identifier: ChiCTR2000029559).

As of April 13, 2020, there are 43 studies registered on Clinicaltrials.gov to examine the
effectiveness of HQ in the treatment of SARS-CoV-2, of which two have a large focus on
prophylaxis but are listed as treatment trials.
Cohort and Observational Studies
In response to the findings of Gautret et al (2020a), a small prospective study tested the
virologic and clinical outcomes of SARS-CoV-2 patients treated with a combination of HQ
(600mg/d for 10 days) and AZM (500mg day 1, 250mg days 2 to 5) (Molina et al, 2020). Of the
11 patients, treatment was discontinued in 1 patient due to QT prolongation, 1 patient died and
2 were admitted to ICU. Overall, 8 out of 10 patients (80%, 95% CI: 49 94) had nasopharyngeal
swabs still testing positive for SARS-CoV-2 RNA at study day 5 to 6. HQ and AZM showed no
difference in this study, contrasting the findings of the Gautret and colleagues study (2020a).
A follow-up observational cohort study by Gautret and colleagues (2020b) examined the efficacy
of HQ in combination with AZM in 80 SARS-CoV-2 patient. Patients were included in the
analysis if they received treatment for at least 3 days with follow-up for at least 6 days.
Treatment offered to patients without contraindications was HQ at 200mg 3 times per day for 10
days & AZM at 500mg on day 1, followed by 250mg/day for the next 4 days. Of the included
patients, 81.3% showed clinical improvement on a combination treatment of HQ & AZM, 15%
required oxygen therapy, 3 patients were admitted to ICU and one 86yo patient died in the
Infectious Disease unit. The authors conclude that there is “efficacy” for the use HQ in
Hydroxychloroquine as treatment/prophylaxis for COVID-19 • 10

combination with AZM for the treatment of COVID-19 (Gautret et al, 2020b). Notably, no control
group was used in this study. As observational studies do not equate to determining efficacy,
the findings are overstated by the authors.
There is a new unpublished abstract just released by the same research group as the Gautret
studies (2020a; 2020b) that reports a cohort study of 1,061 patients treated with a combination
of HQ and AZM for at least 3 days with 9 days follow-up found virological cure in 91.7% of
patients with 4.3% of patients experiencing poor outcomes (ICU admission n=10; hospitalization
longer than 10 days n=31; and death n=5) (Marseilles IHU group, 2020). Older age (OR 1.11)
and initial severity (OR 10.05) were associated with poor clinical outcomes. Currently there is no
manuscript available to assess study quality or examine data and outcomes, however as this
study lacks a control group it contains the same limitations of other observational studies in that
it does not determine efficacy.
Further, a new preprint study examining the effectiveness of HQ in SARS-CoV-2 patients
(n=181) with pneumonia and oxygen requirements of ≥2L/min used routine clinical data to
emulate a target trial. No difference were found between the treatment group (n=84; HQ at
600mg/d started within 48 hours of hospitalization) and the control group (n=94; no HQ for first
48 hours of hospital admission) in either transfer to ICU within 7 days (20.2% vs 22.1%,
respectively; relative risk [RR]: 0.91, 95%CI: 0.47, 1.80) or mortality within 7 days (2.8% vs
4.6%; RR: 0.61, 95%CI: 0.13, 2.89) (Mahévas et al, 2020). Notably, HQ was discontinued for
eight patients in the treatment group due to changes in their electrocardiogram (ECG).
Current State of Recommendations in Other Jurisdictions
The early ‘findings’, in combination with anecdotal perspectives, spurred several regions (CDC
MICC Team, 2020; Hinton, 2020; Mount Sinai, 2020; Multicenter Collaboration Group, 2020;
Sciensano, 2020) to support the use of CQ/HQ in SARS-CoV-2 patients, despite a severe
paucity of evidence to support the effectiveness and safety of these medications within this
population. There are several published letters (Dong et al, Gao et al) and a Handbook for
diagnosis and management of COVID-19 from China (Liang et al). All of these recommend
chloroquine as part of treatment for established COVID-19 pulmonary disease based on the
recent experience of physicians in that country. A recent review on HQ in patients with diabetes
in India concluded that HQ could be used with careful consideration in this population (Singh et
al, 2020).

On March 28, 2020 the US FDA approved an Emergency Use Authorization for the use of CQ
and HQ in SARS-CoV-2 patients (Hinton, 2020, US FDA 2020a; US FDA 2020b). Mount Sinai
Health System has released treatment guidelines for use of HQ in COVID-19 patients stating
that Infectious Disease (ID) consultation is available for COVID-19 patients but ID approval to
prescribe HQ and AZM for treatment is not required (Mount Sinai, 2020). Conversely, European
guidelines on the use of HQ in critically ill patients states there is insufficient evidence to
recommend the use of CQ or HQ in critically ill adults with SARS-CoV-2 (Alhazzani et al, 2020).
Insufficient evidence is also reported by several others (Agency for Care Effectiveness, 2020;
Lenzer, 2020; Lowe D, 2020; Mc Cormack, 2002; Sciensano, 2020; Yazdany & Kim, 2020).
Hydroxychloroquine as treatment/prophylaxis for COVID-19 • 11

The American Heart Association, American College of Cardiology, and heart Rhythm Society
have recommended that HQ and azithromycin be withheld in patients with baseline QT
prolongation.
What is the evidence that HQ is effective as a prophylaxis for COVID-19?
The aforementioned in vitro studies do suggest potential benefit for HQ as a prophylactic for
SARS-CoV-2 (Lui et al, 2020; Mackenzie, 1983; Wang et al, 2020; Yao et al, 2020). As of April
13, 2020, there are no available data from randomized clinical trials, cohort or observational
studies to inform clinical guidance on the use, dosing, or duration of chloroquine (CQ) or
hydroxychloroquine (HQ) for prophylaxis of SARS-CoV-2 infection.
There are 21 clinical trials registered on clinicaltrials.gov whose purpose is to study the
effectiveness of CQ or HQ prophylaxis in healthcare workers or household contacts of people
known to be COVID-19 positive.
There is a document circulating on Twitter that indicates that India has approved HQ
prophylaxis for healthcare workers and household contacts in that country (Barghava, 2020). It
appears that the rationale for approving it for prophylaxis is an extension of its benefits when
used in treatment. Reports of toxicity have also circulated (see next Section).
In summary, there are no data to support the use of HQ as a prophylactic in SARS-CoV-2
patients. In the setting of known potential harms, HQ for SARS-CoV-2 prophylaxis should be
avoided until there is quality trial data available (Kim et al 2020, Yazdany & Kim, 2020).
What are the risks of using HQ prophylactically or as treatment for COVID-19?
Since an early, now highly criticized, study (Gautret et al, 2020a) suggested that a combination
of HQ and Azithromycin (AZM) resulted in improvement of clinical outcomes and viral loads in
SARS-CoV-2 patients, many jurisdictions and clinicians have adopted the regimen; however,
there is insufficient evidence to support this treatment combination in SARS-CoV-2 patients.

A new user cohort study (n=351,956) examined the risk associated with the addition of AZM to
HQ treatment in patients with rheumatoid arthritis to guide decision making during the COVID-
19 pandemic. The study reported an increased risk of 30-day cardiovascular mortality
(calibrated hazard ratio [CalHR] 2.19 [95% CI 1.22, 3.94]), chest pain/angina (CalHR 1.15 [95%
CI 1.05, 1.26]), and heart failure (CalHR 1.22 [95% CI 1.02, 1.45]) (Lane et al, 2020).

In SARS-CoV-2 patients, a preprint retrospective study of 84 consecutive adult patients found
significant QTc prolongation (p500ms (Chorin, E et al, 2020). In this study, both
baseline QTc and QTc >460ms were not reliable predictors of significant QTc prolongation.

A case study of a comorbid 70yo female initially treated for community-acquired pneumonia
describes that following a positive test for SARS-CoV-2, the patient was prescribed HQ starting
1 day after AZM and ceftriaxone were discontinued. The patient suffered ventricular fibrillation
and cardiac arrest on day 5 of HQ due to QTc prolongation from a combination of HQ and AZM.
HQ was prescribed after stopping AZM; however, it is suspected that the long half-life of AZM
would put concentration still near or at therapeutic concentration (ISMP, 2020).
Hydroxychloroquine as treatment/prophylaxis for COVID-19 • 12

Further, a parallel, double-blind randomized Phase IIb clinical trial (ClinicalTrials.gov, number
NCT04323527) run out of Brazil examining CQ use in SARS-CoV-2 patients was forced to shut
down recruitment due to fatal cardiac complications in the high dose group, the dosing level
recommended by Chinese guidelines (no in-text citation provided in current preprint) (Silva
Borba et al, 2020). A total of 81 patients were enrolled into the trial (virological confirmation
n=40; clinical-epidemiological suspicion n=41). Patients randomized to the low CQ dose arm
received 400mg for 5 days, b.i.d. only on day 1 (total CQ= 2.7g) and the high CQ dose arm
received 600mg b.i.d. for 10 days (total CQ = 12g). All patients were given azithromycin and
ceftriaxone. Patient characteristics were similar between each group apart from all patients
>75yo (n=5) were enrolled in the high dose arm. In the intention to treat population until Day 6
showed no differences in either safety outcomes (QTc prolongation [using Fridericia’s formula],
increased creatinine, decreased hemoglobin or ventricular tachycardia) or efficacy outcomes
including death, admission to ICU, need for inotropics, oxygen support needed, invasive
mechanical ventilation or naso/oropharyngeal swab viral clearance which was measured on Day
4. The fatality rate until Day 6 was 13.5% (95%CI: 6.9, 23.0%; n=11) with a trend of higher
fatalities in the high dose group. Due to these findings, the high dose arm of the study was
interrupted to unmask and transition patients to the low dose arm. The authors conclude that
treatment with high dose CQ for 10 days is not sufficiently safe and should no longer be used in
severe SARS-CoV-2 patients (Silva Borba et al, 2020).

Safety considerations for the use of CQ, HQ and AZM or other macrolide antibiotics in the
management of SARS-CoV-2 infections identified the potential risks of treatment using CQ/HQ
to include QTc prolongation (Chorlin et al, 2020), particularly in patients with pre-existing cardiac
disease or if used in combination with AZM, as well as other known risks associated with these
drugs including hypoglycemia (Unübol M et al, 2011), drug-drug interactions (Somer M et al,
2000) and neuropsychiatric effects (Das P et al, 2014). Although in vitro studies and low quality
human studies suggest the use of CQ/HQ in the treatment and prevention of SARS-CoV-2,
clinicians and patients should be aware of the potential risks associated with this treatment,
particularly in the absence of high quality evidence of this treatment within humans (Juurlink,
2020). Use of a tool (Tisdale et al, 2013) to access the risk of QTc prolongation must be
considered when evaluating the benefit vs harm of using HQ as treatment in SARS-CoV-2
patients.

General Considerations regarding HQ use
Given that HQ is more readily available in Canada, the focus of this section is on HQ. Moreover,
CQ is 2-3 times more toxic than HQ in animal studies, hence the use of CQ for malaria
prophylaxis and HQ as an anti-inflammatory for patients with lupus or rheumatoid arthritis.
The daily doses of HQ in the trials listed above range from 200 to 600 mg/day for 4 days. In two
of the trials, a loading dose of 800 mg X 1 dose precedes the daily dose. This is the same as
the current treatment dose as described in the AHS COVID-19 antimicrobial treatment
document (AHS, 2020).
1. Adverse effects
Hydroxychloroquine as treatment/prophylaxis for COVID-19 • 13

The following Council for International Organizations of Medical Sciences (CIOMS) frequency
rating for adverse effects is used, when applicable:

   •   Very common: ≥ 10 %
   •   Common: ≥ 1 and
Hydroxychloroquine as treatment/prophylaxis for COVID-19 • 14

One of the most concerning aspects of CQ is its toxicity in children with unintentional ingestions
of someone else’s medication. Ingestion of as little as 1-2 grams can be fatal to small children
(ToxiNZ 2020, Cann 1961, Kelly 1990).
Pediatric patients with CQ or HQ toxicity may present with severe manifestations of the adverse
effects listed above. This includes seizures, coma, hypoglycemia and dysrhythmias. Since
hospitalized patients have their medications administered to them and are stored away from
children, unintentional pediatric access is much less of an issue. If used for prophylaxis, it must
be anticipated that there will be up to 5 days’ worth of HQ pills in homes with children in them.
A toxic dose for both adult and pediatric patients has not been established. Having said that, a
pediatric dose of HQ for malaria treatment is 25 mg/kg over 3 days. Hence, a 2 year old
weighing 14 kg would require a total of 350 mg over 3 days.
Using the prophylactic doses above, and assuming the ingestion occurred all at once, there may
be anywhere from 1600-3200 mg in the house, for an estimate of 114-228 mg/kg in the same 2
year old.
How stable is the supply of HQ to Alberta?

Chloroquine
Chloroquine is currently on long term back order, therefore there is no anticipated availability in
Alberta at this time.
Hydroxychloroquine
Within Alberta Health Services, all current supply of hydroxychloroquine is restricted to patients
admitted with COVID-19, as outlined in the Recommendations for Antimicrobial
Management of Adult Hospitalized Patients with COVID-19:
https://www.albertahealthservices.ca/assets/info/ppih/if-ppih-covid-19-recommendations.pdf
(AHS, 2020).
At this time, AHS is confident that there is adequate supply to continue to treat all patients
previously on hydroxychloroquine as well as 4,300 patients that would be admitted to an AHS or
Covenant facility with COVID-19, assuming treatment of 14 tablets per patient. The current
projections for admitted patients is slightly above 2000 patients. AHS continues to work to
obtain additional supply of hydroxychloroquine to manage our patient’s needs. Additional
sources being looked into include, but are not limited to:
   1) Securing additional supply from our current supplier
   2) Securing supply announced by Jamp Pharmaceuticals on March 23rd. How supplied is to
      be divided between the different health authorities has not yet been confirmed
At this time, all hydroxychloroquine prescribing needs to be restricted to hospitalized patients
with COVID-19, in accordance with the Recommendations for Antimicrobial Management of
Adult Hospitalized Patients with COVID-19. Use for treatment for non-hospitalized patients or
prophylaxis for patients/health care providers is not permitted at this time.
Hydroxychloroquine as treatment/prophylaxis for COVID-19 • 15

In the community, there is limited supply of hydroxychloroquine. The Canadian Pharmacists
Association has issued a statement recommending against using hydroxychloroquine in
ambulatory patients (Canadian Pharmacists Association, 2020), as has the College of
Physicians and Surgeons of Alberta (CPSA, 2020).
Hydroxychloroquine as treatment/prophylaxis for COVID-19 • 16

Reference List
Agency for Care Effectiveness. Can Antimalarials Be Used to Treat COVID-19? Appropriate
Care Guides, Agency for Care Effectiveness (Singapore). http://www.ace-hta.gov.sg/public-
data/covid-19-resources/Antimalarials%20for%20COVID-19%20(25%20March%202020).pdf.
Updated March 25, 2020. Accessed April 12, 2020.

Alberta College of Pharmacy. Prescribing of Drugs to Treat COVID-19 for the Purposes of
Stockpiling. https://abpharmacy.ca/covid-19-guidance-pharmacists-and-pharmacy-technicians.
Updated April 9, 2020. Accessed April 10, 2020.
Alberta Health Services. Recommendations for Antimicrobial Management of Adult Hospitalized
Patients with COVID-19. https://www.albertahealthservices.ca/assets/info/ppih/if-ppih-covid-19-
recommendations.pdf. Updated March 22, 2020. Accessed April 12, 2020.
Alhazzani, W., Møller, M. H., Arabi, Y. M., Loeb, M., Gong, M. N., Fan, E., Dzierba, A. Surviving
sepsis campaign: guidelines on the management of critically ill adults with coronavirus disease
2019 (COVID-19). Intensive Care Medicine. 2020; 1-34. https://www.esicm.org/wp-
content/uploads/2020/03/SSC-COVID19-GUIDELINES.pdf. Accessed April 13, 2020.
Barghava, B. Advisory on the Use of Hydroxy-chloroquinone as Prophylaxis for SARS-CoV-2
Infection. Indian Council of Medical Research. New Delhi: India. 2020.
https://www.mohfw.gov.in/pdf/AdvisoryontheuseofHydroxychloroquinasprophylaxisforSARSCoV
2infection.pdf. Published March 22, 2020. Accessed April 13, 2020.
Canadian Pharmacists Association. Treatment of COVID-19 with Chloroquine or
Hydroxychloroquine. https://www.pharmacists.ca/cpha-ca/assets/File/cpha-on-the-issues/CQ-
HCQ-COVID-FINAL-EN.pdf. Updated April 12, 2020. Accessed April 12, 2020.
Cann HM, Verhulst MS. Fatal Acute Chloroquine poisoning in children. Pediatrics. 1961;27;95.
https://pediatrics.aappublications.org/content/27/1/95. Accessed April 14, 2020.
Carson III JW, Barringer ML, Jones III RE. Fatal Chloroquine Ingestion: An Increasing Hazard.
Pediatrics. 1967;40;449. http://pediatrics.aappublications.org/content/40/3/449. Accessed April
14, 2020.
CDC MICC Team. Treatment of Confirmed COVID-19 cases by CDC MICC Team.
https://www.medcampus.io/mnotes/protocol-for-treatment-of-confirmed-covid-19-
5e5e2781e86c5d0001f77303. Updated February 28, 2020. Accessed April 12, 2020.
Chen C-Y, Wang F-L and Lin C-C. Chronic hydroxychloroquine use associated with
QT prolongation and refractory ventricular arrhythmia. Clinical Toxicology.
2006;44,173-175. https://www.tandfonline.com/doi/full/10.1080/15563650500514558. Accessed
April 13, 2020.

Chen J, Liu D, Liu L, et al. A pilot study of hydroxychloroquine in treatment of patients with
common coronavirus disease-19 (COVID-19). J Zhejiang Univ (Med Sci). 2020;49.
http://www.zjujournals.com/med/EN/10.3785/j.issn.1008-9292.2020.03.03. Accessed April 10,
2020.
Hydroxychloroquine as treatment/prophylaxis for COVID-19 • 17

Chen Z, et al. Efficacy of hydroxychloroquine in patients with COVID-19: Results of a
randomized clinical Trial. 2020. MedRxiv preprint. https://doi.org/10.1101.2020.03.22.20040758.
Accessed April 13, 2020.
Chorin, et al. The QT interval in patients with SARS-CoV-2 Infection Treated with
Hydroxychloroquine/Azithromycin.
https://www.medrxiv.org/content/10.1101/2020.04.02.20047050v1. Published April 3, 2020.
Accessed April 13, 2020.
Clinicaltrials.gov. Search Terms: Hydroxychloroquine and Coronavirus.
https://clinicaltrials.gov/ct2/results?term=hydroxychloroquine&cond=COVID-19. Updated April
13, 2020. Accessed April 13, 2020.
Dahly, D., Gates, S., & Morris, T. Statistical review of hydroxychloroquine and azithromycin as a
treatment of COVID-19: Results of an open-label non-randomized clinical trial. Covid-19 Ad Hoc
Papers. 2020. https://zenodo.org/record/3725560#.XpSqxvacE2w. Published March 23, 2020.
Accessed April 13, 2020.
Das P, Rai A, Chopra A, et al. Psychosis likely induced by hydroxychloroquine in a patient with
chronic Q fever: a case report and clinically relevant review of pharmacology. Psychosomatics
2014;55:409-13. https://www.sciencedirect.com/sdfe/pdf/download/eid/1-s2.0-
S0033318213001321/first-page-pdf. Accessed April 13, 2020.
Dong, L., Hu, S., & Gao, J. Discovering drugs to treat coronavirus disease 2019 (COVID-
19). Drug Discoveries & Therapeutics, 14(1), 58–60. https://doi.org/10.5582/ddt.2020.01012.
Accessed April 13, 2020.
Frie, K., & Gbinigie, K. Chloroquine and Hydroxychloroquine: Current Evidence for their
Effectiveness in Treating COVID-19. Centre for Evidence-Based Medicine, University of Oxford.
https://www.cebm.net/covid-19/chloroquine-and-hydroxychloroquine-current-evidence-for-their-
effectiveness-in-treating-covid-19/. Published March 25, 2020. Accessed April 13, 2020.
Gao, J., Tian, Z., & Yang, X. (2020). Breakthrough: Chloroquine phosphate has shown apparent
efficacy in treatment of COVID-19 associated pneumonia in clinical studies. Bioscience
trends, 14(1), 72–73. https://doi.org/10.5582/bst.2020.01047
Gautret, P., Lagier, J. C., Parola, P., Meddeb, L., Mailhe, M., Doudier, B. & Honoré, S.
Hydroxychloroquine and azithromycin as a treatment of COVID-19: Results of an open-label
non-randomized clinical trial. International Journal of Antimicrobial Agents. 2020a. 105949.
https://www.medrxiv.org/content/medrxiv/early/2020/03/20/2020.03.16.20037135.full.pdf.
Accessed April 23, 2020.
Gautret P, Lagier JC, Parola P et al. Clinical and microbiological effect of a combination of
hydroxychloroquine and azithromycin in 80 COVID-19 patients with at least a six-day follow up:
An observational study. 2020b. In-press. https://www.mediterranee-infection.com/wp-
content/uploads/2020/03/COVID-IHU-2-1.pdf. Accessed April 12, 2020.
Hinton D. Re: Request for Emergency Use Authorization for Use of Chloroquine Phosphate or
Hydroxychloroquine Sulfate Supplied from the Strategic National Stockpile for Treatment of
Hydroxychloroquine as treatment/prophylaxis for COVID-19 • 18

2019 Coronavirus Disease [response letter to Bright R]. Washington (DC): United States Food
and Drug Administration. www.fda.gov/media/136534/download. Published March 28, 2020.
Accessed April 12, 2020.
Infectious Diseases Society of America (IDSA). Infectious Diseases Society of America
Guidelines on the Treatment and Management of Patients with COVID-19.
https://www.idsociety.org/practice-guideline/covid-19-guideline-treatment-and-management/
Accessed April 13, 2020.
Institute for Safe Medication Practices (IMSP). Patient Taking Hydroxychloroquine Right After
Discontinuing Azithromycin Develops QTc Prolongation and Cardiac Arrest.
https://ismp.org/acute-care/special-edition-medication-safety-alert-april-9-2020/covid-19.
Published April 9, 2020. Accessed April 12, 2020.
Juurlink DN. Safety Considerations with Chloroquine, Hydroxychloroquine and Azithromycin in
the Management of SARS-CoV-2 Infection. CMAJ. 2020.
https://www.cmaj.ca/content/early/2020/04/08/cmaj.200528. Published April 8, 2020. Accessed
April 13, 2020.

Kelly JC, Wasserman GS, Bernard WD, Schultz C, Knapp J. Chloroquine poisoning in a child.
Ann Emerg Med. 1990 Jan;19(1):47-50. https://www.annemergmed.com/article/S0196-
0644(05)82141-9/fulltext. Accessed April 14, 2020.
Keyaerts, E., Vijgen, L., Maes, P., Neyts, J., & Van Ranst, M. In vitro inhibition of severe acute
respiratory syndrome coronavirus by chloroquine. Biochemical and Biophysical Research
Communications. 2004;323(1), 264–268. https://doi.org/10.1016/j.bbrc.2004.08.085. Accessed
April 13, 2020.
Keyaerts, E., Li, S., Vijgen, L., Rysman, E., Verbeeck, J., Van Ranst, M., & Maes, P. (. Antiviral
activity of chloroquine against human coronavirus OC43 infection in newborn
mice. Antimicrobial Agents and Chemotherapy. 53(8), 3416–3421.
https://doi.org/10.1128/AAC.01509-08. Accessed April 30, 2020.
Kim, A. H., Sparks, J. A., Liew, J. W., Putman, M. S., Berenbaum, F., Duarte-García, A., . . .
Sirotich, E. A rush to judgment? Rapid reporting and dissemination of results and its
consequences regarding the use of hydroxychloroquine for COVID-19. Ann Intern Med. 2020;
M20-1223. https://www.ncbi.nlm.nih.gov/pubmed/32227189. Accessed April 13, 2020.
Kono, M., Tatsumi, K., Imai, A. M., Saito, K., Kuriyama, T., & Shirasawa, H. Inhibition of human
coronavirus 229E infection in human epithelial lung cells (L132) by chloroquine: involvement of
p38 MAPK and ERK. Antiviral Research. 2002; 77(2), 150–152.
https://doi.org/10.1016/j.antiviral.2007.10.011. Accessed April 13, 2020.
Lenzer, J. Covid-19: US gives emergency approval to hydroxychloroquine despite lack of
evidence. BMJ. 2020; 369, m1335. https://www.bmj.com/content/369/bmj.m1335. Accessed
April 13, 2020.
Hydroxychloroquine as treatment/prophylaxis for COVID-19 • 19

Liang, T. Handbook of COVID-19 Prevention and Treatment. Zhejiang University School of
Medicine, China. 2020. https://iau-aiu.net/Zhejiang-University-Handbook-of-COVID-19-
Prevention-and-Treatment. Published March 24, 2020. Accessed: April 13, 2020.
Lowe, D. The Latest Hydroxychloroquine Data, As of April 11 (blog).
https://blogs.sciencemag.org/pipeline/archives/2020/04/11/the-latest-hydroxychloroquine-data-
as-of-april-11. Published April 11, 2020. Accessed April 12, 2020.
Liu, J., Cao, R., Xu, M., Wang, X., Zhang, H., Hu, H., Li, Y., Hu, Z., Zhong, W. and Wang, M.,
Hydroxychloroquine, a less toxic derivative of chloroquine, is effective in inhibiting SARS-CoV-2
infection in vitro. Cell Discovery. 2020; 6(16), pp.1-4. https://www.nature.com/articles/s41421-
020-0156-0. Accessed April 13, 2020.
Mackenzie, AH. Dose refinements in long-term therapy of rheumatoid arthritis with antimalarials.
Am J Med Sci. 1983; 75(1), 40-45. https://doi.org/10.1016/0002-9343(83)91269-X. Accessed
April 13, 2020.
Mahévas, M., Tran, V-T., Roumier, M., Chabrol, A., Paule, R., Guillaud, C., et al. No evidence of
clinical efficacy of hydroxychloroquine in patients hospitalised for COVID-19 infection and
requiring oxygen: results of a study using routinely collected data to emulate a target trial. 2020.
medRxiv preprint. https://doi.org/10.1101/2020.04.10.20060699. Accessed April 14, 2020.
Metz LM, et al. Alberta Hope COVID-19: A randomized, double-blind placebo-controlled trial to
assess the efficacy and safety of oral hydroxychloroquine for the treatment of SARS-CoV-2
positive patients for the prevention of severe COVID-19 disease. Protocol Number: ABCOV-01
v1.1. https://clinicaltrials.gov/ct2/show/NCT04329611. Updated April 7, 2020. Accessed April 13,
2020.
McCormack, J. Hydroxychloroquine With or Without Azithromycin for COVID-19.
https://bccfp.bc.ca/wp-content/uploads/2020/03/Hydrochloroquine-with-or-without-azithromycin-
for-COVID.pdf. Accessed April 13, 2020.
Morgan ND, Patel SV and Dvorkina O. Suspected hydroxychloroquine-associated
QT-interval prolongation in a patient with systemic lupus erythematosus.
Journal of Clinical Rheumatology. 2013;19(5),286-288.
https://www.ncbi.nlm.nih.gov/pubmed/23872551. Published August 2013. Accessed April 12,
2020.
Marseilles IHU group. Abstract (no title). https://www.mediterranee-infection.com/wp-
content/uploads/2020/04/Abstract_Raoult_EarlyTrtCovid19_09042020_vD1v.pdf . Accessed
April 12, 2020.
Molina JM, Delaugerre C, Goff J, et al. No Evidence of Rapid Antiviral Clearance or Clinical
Benefit with the Combination of Hydroxychloroquine and Azithromycin in Patients with Severe
COVID-19 Infection. Médecine et Maladies Infectieuses 2020.
Mount Sinai. Mount Sinai Health System Treatment Guidelines for SARS-CoV-2 patients.
https://www.mountsinai.org/files/MSHealth/Assets/HS/About/Coronavirus/MSHS-Treatment-
Guidelines-COVID.pdf. Updated April 10, 2020. Accessed April 13, 2020.
Hydroxychloroquine as treatment/prophylaxis for COVID-19 • 20

Multicenter collaboration group of Department of Science and Technology of Guangdong
Province and Health Commission of Guangdong Province for chloroquine in the treatment of
novel coronavirus pneumonia. Expert consensus on chloroquine phosphate for the treatment of
novel coronavirus pneumonia]. Zhonghua Jiehe He Huxi Zazhi 2020 Mar 12;43(3):185e8.
https://doi.org/10.3760/cma.j.issn.1001-0939.2020.03.009.. Access April 13, 2020. English
Abstract Only.

Retraction Watch. Hydroxychloroquine-COVID-19 study did not meet publishing society’s
“expected standard.” https://retractionwatch.com/2020/04/06/hydroxychlorine-covid-19-study-
did-not-meet-publishing-societys-expected-standard/. Published April 6, 2020. Accessed April
10, 2020.

Roden DM. Predicting drug-induced QT prolongation and torsades de pointes. J Physiol.
2016;594(9):2459-68. https://www.ncbi.nlm.nih.gov/pubmed/26660066. Accessed April 13,
2020.

Sanofi-Aventis Canada Inc. Product Monograph: Plaquenil.
http://products.sanofi.ca/en/plaquenil.pdf. Updated August 26, 2019. Accessed April 13, 2020.

Sciensano. Interim clinical guidance for patients suspected of/confirmed with COVID-19 in
Belgium. https://epidemio.wiv-isp.be/ID/Documents/Covid19/COVID-
19_InterimGuidelines_Treatment_ENG.pdf. Updated April 7, 2020. Accessed April 12, 2020.

Singh, A. K., Singh, A., Shaikh, A., Singh, R., & Misra, A. Chloroquine and hydroxychloroquine
in the treatment of COVID-19 with or without diabetes: A systematic search and a narrative
review with a special reference to India and other developing countries. Diabetes & Metabolic
Syndrome: Clinical Research & Reviews. May-June 2020; 14(3), 241-246.
https://www.sciencedirect.com/science/article/pii/S1871402120300515. Accessed April 13,
2020.

Silva Borba MG, Val FFA, Sampaio VS, et al. Chloroquine diphosphate in two different dosages
as adjunctive therapy of hospitalized patients with severe respiratory syndrome in the context of
coronavirus (SARS-CoV-2) infection: Preliminary safety results of a randomized, double-
blinded, phase IIb clinical trial (CloroCovid-19 Study). 2020.
https://www.medrxiv.org/content/10.1101/2020.04.07.20056424v1.full.pdf. Accessed April 13,
2020.

Smith ER, Klein-Schwartz W. Are 1-2 Dangerous? Chloroquine and Hydroxychloroquine
Exposure in Toddlers. J Emerg Med, 2005; 28(4), 437-43.
https://pubmed.ncbi.nlm.nih.gov/15837026/. Accessed April 13, 2020.
Somer M, Kallio J, Pesonen U, et al. Influence of hydroxychloroquine on the bioavailability of
oral metoprolol. Br J Clin Pharmacol 2000;49:549-54.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2015042. Accessed April 13, 2020.
Tisdale JE, Jaynes HA, Kingery JR, et al. Development and validation of a risk score to predict
QT interval prolongation in hospitalized patients. Circ Cardiovasc Qual Outcomes. 2013
Jul;6(4):479-87. doi: 10.1161/CIRCOUTCOMES.113.000152.
Hydroxychloroquine as treatment/prophylaxis for COVID-19 • 21

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3788679/pdf/nihms490533.pdf . Accessed April
14, 2020.
Hydroxychloroquine. In ToxiNZ Poisons Information Database [database online]. Dunedin, NZ:
New Zealand National Poisons Centre; 2020. https://www.toxinz.com. Accessed April 13, 2020.
Unübol M, Ayhan M, Guney E. Hypoglycemia induced by hydroxychloroquine in a patient
treated for rheumatoid arthritis. J Clin Rheumatol 2011;17:46-7.
https://insights.ovid.com/article/00124743-201101000-00012. Accessed April 13, 2020.
US Food and Drug Administration (FDA) 2020a. Fact Sheet for Healthcare Providers - EUA for
Hydroxychloroquine Sulfate for COVID-19, version date 3/28/2020.
https://www.fda.gov/media/136537/download. Updated April 3, 2020. Accessed April 12, 2020.
US Food and Drug Administration (FDA) 2020b. Fact Sheet for Patients and Parent/Caregivers:
EUA of Hydroxychloroquine Sulfate for Treatment of COVID-19 in Certain Hospitalized Patients,
version date 3/28/2020. https://www.fda.gov/media/136538/download. Updated March 28, 2020.
Accessed 2020 April 12.
Vincent, M. J., Bergeron, E., Benjannet, S., Erickson, B. R., Rollin, P. E., Ksiazek, T. G., Seidah,
N. G., & Nichol, S. T. Chloroquine is a potent inhibitor of SARS coronavirus infection and
spread. Virology journal. 2005; 2(69). https://doi.org/10.1186/1743-422X-2-69. Accessed April
13, 2020.
Wang L.F., Lin Y.S., Huang N.C., Yu C.Y., Tsai W.L., Chen J.J. Hydroxychloroquine-inhibited
dengue virus is associated with host defense machinery. J Interferon Cytokine Res.
2015;35(3),143–156. https://www.ncbi.nlm.nih.gov/pubmed/25321315. Accessed April 13, 2020.

Wang, M., Cao, R., Zhang, L., Yang, X., Liu, J., Xu, M., Shi, Z., Hu, Z., Zhong, W., & Xiao, G.
Remdesivir and chloroquine effectively inhibit the recently emerged novel coronavirus (2019-
nCoV) in vitro. Cell Research. 2020; 30(3), 269–271. https://doi.org/10.1038/s41422-020-0282-
0. Accessed April 13, 2020.
Yao, X., Ye, F., Zhang, M., Cui, C., Huang, B., Niu, P., Liu, X., Zhao, L., Dong, E., Song, C.,
Zhan, S., Lu, R., Li, H., Tan, W., & Liu, D. In Vitro Antiviral Activity and Projection of Optimized
Dosing Design of Hydroxychloroquine for the Treatment of Severe Acute Respiratory Syndrome
Coronavirus 2 (SARS-CoV-2). Clinical infectious diseases: an official publication of the
Infectious Diseases Society of America, ciaa237. 2020. Advance online publication.
https://doi.org/10.1093/cid/ciaa237. Accessed April 13, 2020.
Yazdany J, Kim AHJ. Use of hydroxychloroquine and chloroquine during the COVID-19
pandemic: What every clinician should know. Ann Intern Med. 2020.
https://annals.org/aim/fullarticle/2764199/use-hydroxychloroquine-chloroquine-during-covid-19-
pandemic-what-every-clinician. Accessed April 13, 2020.

Additional Resources
1. LexiComp database
2. Micromedex database
3. ToxiNZ Poison Information database
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