Yuri Clement1, Satish Jankie2, Shalini Pooransingh1, Diane Ignacio2, Avril E. Reid3, Shurla Sampson-Francis1, Stanley Giddings4, Harold Watson5
1Department of Para-clinical Sciences, 2School of Pharmacy, 3Medical Sciences Library, 4Department of Clinical Medical Sciences, Faculty of Medical Sciences, The University of the West Indies, St, Augustine, Trinidad and Tobago.
5Department of Medicine, Faculty of Medical Sciences, The University of the West Indies, Cave Hill, Barbados.
Corresponding author:
Yuri Clement, PhD
Department of Paraclinical Sciences
Faculty of Medical Sciences
St. Augustine
Trinidad and Tobago
Telephone/Fax: 1-868-663-8613
Email: [email protected]
Copyright: This is an open-access article under the terms of the Creative Commons Attribution License which permits use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Objectives: To review the published evidence of repurposed drugs, antivirals and biologics for the treatment of COVID-19.
Materials and Methods: A literature review was conducted in several databases and research portals. Search terms included COVID-19, SARS-Cov-2, MERS, MERS-CoV, SARS, SARS-CoV, coronavirus, beta-coronavirus, influenza, pneumonia and several drugs considered for use in COVID-19.
Results: There is a paucity of clinical evidence regarding the safety and efficacy of most agents being considered for the treatment of COVID-19. However, based on promising preliminary research the US Food and Drugs Administration has authorized the emergency use of hydroxychloroquine and remdesivir for hospitalized COVID-19 patients. To date, the most robust evidence for lopinavir-ritonavir (LPV/r) found that it was no better than standard care. Overwhelming evidence suggests that corticosteroids increase mortality, nosocomial infections and lengthen hospitalization in SARS and MERS patients, and should be used cautiously in patients with severe respiratory symptoms. Additionally, low level evidence suggests that tocilizumab may be useful to reduce the cytokine storm precipitated by SARS-CoV-2 infection.
Conclusions: Hydroxychloroquine and remdesivir have surged to the front of the race to repurpose drugs in the fight against COVID-19. With hundreds of ongoing trials it is envisaged that indisputable evidence would be provided for prophylactic and therapeutic use of drugs and biologics within the next few months. However, in our setting it would be worthwhile to consider the availability and accessibility of some of these agents.
Introduction
The world is facing its second pandemic of the 21st century caused by a new coronavirus, SARS-CoV-2, that emerged in China in December 2019. In February 2020 the World Health Organization (WHO) announced an official name for the disease caused by SARS-CoV-2 as Coronavirus Disease 2019 (COVID-19). Similar to the emergence of severe acute respiratory syndrome (SARS-CoV) in 2003 and Middle East respiratory syndrome (MERS-CoV) in 2012, SARS-CoV-2 is a Betacoronavirus which may have originated in bats.1 As of 07thMay 2020, there were over 3.8 million persons with confirmed SARS-CoV-2 infection worldwide and COVID-19 has claimed the lives of over 265,000.2
There are currently no approved drugs for COVID-19 and several clinical trials are ongoing. However, several drugs approved for other conditions are also being considered as probable treatment options and some countries are using anecdotal evidence, laboratory-based studies and limited clinical studies to guide drug use in critically-ill hospitalized patients. On 28th March 2020, the US Food and Drugs Administration authorized the emergency use of chloroquine phosphate and hydroxychloroquine sulphate for certain hospitalized patients.3
This literature review presents the most current evidence for a number of drugs being considered as possible treatments for COVID-19. It was recognized that there may be few studies that specifically evaluated the efficacy of drugs against SARS-CoV-2; therefore, we included studies in similar respiratory tract infections, including severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS) and influenza.
Methodology
A review of the literature was conducted, in the following databases and research portals: PubMed, NIH Clinical Trials Database, Cochrane, Evidence Portal of the UK National Institute for Health and Care Excellence (NICE) the EPPI-Centre and UpToDate©.
Articles from pre-defined searches for COVID-19 treatment were reviewed. Searches were also conducted for chloroquine, hydroxychloroquine, lopinavir/ritonavir, remdesivir, interferon, corticosteroids, umifenovir (arbidol), ribavirin, favipiravir, sofosbuvir, tocilizumab, ivermectin, baricitinib, ruxolitinib and fedratinib AND COVID-19. Additional search terms used included MERS, SARS, coronavirus, betacoronaviruses, SARS-CoV, SARS-CoV-2, influenza, pneumonia, in vivo, in vitro. Filters applied included clinical trials, systematic reviews and meta-analysis. Publishers COVID-19 Special collections were also consulted on Open Access Platforms. We also conducted a search on the use of ibuprofen, angiotensin converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) in COVID-19 as there are concerns regarding worsening of symptoms.
Details of published studies were extracted and the methodological quality assessed using the Cochrane Risk of Bias tool.4 For each drug an overall grade (very low, low, moderate or high) was assigned based on the totality of the evidence.
Results & Discussion
Several drugs approved for other indications and experimental drugs are now being considered as treatment for COVID-19. Findings from laboratory studies, observational studies, small open-labelled studies and anecdotal evidence are guiding emergency use in severe respiratory distress. It is on this premise that this literature review was undertaken to assess the quality of the evidence being advanced for emergency use and to guide clinical trials. Summaries of the identified articles are presented in the following sections. The characteristics of studies and the Cochrane risk of bias tool used to assess the level of evidence of these studies are presented online supplementary files 1 and 2 respectively.
Chloroquine
Chloroquine is a 4-aminoquinoline compound used for prophylaxis and treatment of malaria and amebiasis.5 It also has potent anti-inflammatory properties and is useful in the treatment of rheumatoid arthritis and systemic lupus erythematosus.
The drug inhibits viral growth in cells previously exposed to or following exposure to SARS-CoV virus.6 This study also found that the virus was unable to replicate following chloroquine treatment, probably by increasing lysosomal pH and preventing cell/virus fusion. Additionally, chloroquine negatively affected glycosylation of SARS-CoV and ACE-2 cellular receptors (which are the portals for viral entry into the cell). An in vitro study in Vero E6 cells found that chloroquine affected both entry and post-entry stages of SARS-nCoV-2 infection.7 In addition to its antiviral activity, chloroquine has immune-modulating effects by suppressing cytokine release, which may synergistically enhance its antiviral effect in vivo.8
Chloroquine inhibited cell death in human lung carcinoma A549-avian-influenza A H5N1 infected cells by reducing viral load when administered both as prophylaxis and post-infection.9 The treatment results were replicated in vivo in H5N1 virus-infected mice with a dramatic increase in survival rate from 0% to 70% on day eight post-infection. However, the drug had no effect as prophylaxis to improve survival rates. A randomized, placebo-controlled, double-blinded clinic trial in 1516 eligible participants found that chloroquine prophylaxis (500mg once per day for one week, then once per week for a further 11 weeks) did not prevent infection with influenza (1% versus 2%; relative risk 1·53), but significantly increased the risk of causing adverse effects.10
In the literature search 118 articles were found, of which two were clinical studies using chloroquine in the treatment of COVID-19. The first study, a case report in a symptomatic 34-year old male patient with COVID-19, found that co-administration of clarithromycin and chloroquine resulted in significant clinical improvement.11 The second study was a randomized clinical trial in 81 patients with severe COVID-19.12 This study found that high dose chloroquine (600mg bid for 10 days) had higher mortality (39.0% versus 15.0%) and incidence of QTc prolongation (18.9% versus 11.1%) compared to low dose chloroquine (450mg bid for 10 days).12 It was noted that patients in the high dose group were older and had higher rates of heart disease, which may have put them at higher risk of mortality and side effects. From these findings it could be concluded that chloroquine should not be used as prophylaxis and should be restricted to use under trial conditions.
Hydroxychloroquine
Hydroxychloroquine sulfate is a derivative of chloroquine and in vivo studies show that it is considerably less toxic than the parent compound.13 Similarly, it is an antimalarial drug, with therapeutic use in systemic lupus erythematosus and rheumatoid arthritis. Studies in vitro found that hydroxychloroquine was more potent than chloroquine14 and was effective at very low concentrations against SARS-CoV-2.6
Like chloroquine, hydroxychloroquine causes significant QT prolongation and increases the incidence of sudden cardiac death by blocking the KCNH2-encoded hERG/Kv11.1 potassium channel.15 The US FDA has cited 222 documented cases of QT prolongation due to hydroxychloroquine use with 105 cardiac arrests noted.15 Case reports have noted the incidence of hydroxychloroquine-induced torsades de pointes associated with chronic use of the drug, and more likely in patients with pre-existing prolonged QT intervals. The half-life of hydroxychloroquine is between 32-50 days16, which explains the dangers of long QT syndrome in long term use. However, as it would be associated with long term use of the drug, which is unlikley in COVID-19 patients, as they may use this drug for a few days or weeks.
In the literature search 144 articles were found, of which three were clinical studies using hydroxychloroquine in the treatment of COVID-19. A recent open-labelled, randomized clinical trial in 62 COVID-19-positive patients in China found that hydroxychloroquine (400mg/day) over five days significantly reduced body temperature, recovery time and cough remission time.17 Another open-label non-randomized study in France enrolled 36 patients with confirmed diagnosis of COVID-19.18 Twenty patients were administered hydroxychloroquine (200 mg, tid) over 10 days and six of these patients were also given azithromycin to prevent bacterial superinfection. The researchers found that patients given hydroxychloroquine had a significantly higher rate of testing negative for the virus (virologically cured) six days after treatment compared to those who were not given the drug (70% versus 12.5%, p<0.001).
Moreover, all six patients on combination therapy were virologically cured by day 6, showing a potential synergistic effect. This study had poor methodological quality, being non-randomized, insufficiently powered and with high attrition in the treatment arm. The overall level of evidence from these studies was low.
On 4th April 2020, the US Food and Drugs Administration issued an advisory cautioning against the use of both chloroquine and hydroxychloroquine in non-hospitalized patients, due to increased risk for heart rhythm problems including prolongation of QT interval and ventricular tachycardia, which could be fatal.19 Therefore, it was recommended that use of these drugs be restricted to the hospital setting on a compassionate basis with appropriate monitoring or under strict clinical trial conditions. At this point, there is no clinical evidence to support the prophylactic use of hydroxychloroquine.
Lopinavir/ritonavir
Lopinavir/ritonavir (LPV/r) is a unique protease inhibitor combination sold under the proprietary name Kaletra™. Ritonavir inhibits CYP3A4/5 and subsequently increases the bioavailability of lopinavir.20
In the literature review 73 articles were found; four of these reports were clinical studies using LPV/r in the treatment of COVID-19. A case report of the index patient at the start of the pandemic in China suggested successful treatment of COVID-19 patients with LPV/r.21 Furthermore, two small studies (a retrospective study and a case series) reported clinical improvement in patients with mild or severe COVID-19 symptoms treated with LPV/r with or without arbidol 22 and lopinavir alone.23 A randomized, open-labelled trial in 199 hospitalized patients with severe COVID-19 found that LPV/r was no better than standard care with regards to clinical improvement or throat viral RNA detectability.24 Although the mortality rate at day 28 was lower in the LPV/r-treated group (19.2% versus 25.0%), this was not statistically significant.
There was a notable benefit in the reduced time spent in ICU (median, 6 days vs. 11 days; difference, −5 days; 95% CI, −9 to 0). However, use of LPV/r produced higher rates of gastrointestinal adverse events where 13 out of 99 patients (13.8%) stopped treatment due to side effects. It was uncertain whether the sample size was sufficiently powered to detect a statistical difference. Overall, this intervention was not beneficial and further studies should include well-designed, placebo-controlled trials that would provide unequivocal evidence. Nonetheless, the level of evidence from this study was moderate. From these findings it could be concluded that LPV/r may not have efficacy in the treatment of COVID-19 and should be restricted to use under trial conditions.
Remdesivir
Remdesivir is a nucleotide analogue inhibitor of RNA-dependent RNA polymerases and has broad-spectrum antiviral activity at a post-entry stage following viral entry into the cell.25 Tchesnokov and colleagues26 reported that remdesivir was active against the Ebola virus. A comparative, randomized clinical study evaluated four investigational therapies (including remdesivir) in addition to standard care in 681 persons infected with Ebola; unfortunately, remdesivir was discontinued in the trial as it was inferior to other treatments with respect to reducing mortality rate.27
An in vitro study found that remdesivir and chloroquine effectively blocked SARS-CoV-2 infection at very low concentrations, with high selectivity.28 The in vivo aspect of this study found that remdesivir reduced the viral load in mice lung tissue infected with MERS-CoV in addition to improving lung function and lessening pathological damage to the tissue. Remdesivir and interferon β had superior antiviral activity against MERS-CoV compared to lopinavir and ritonavir in vitro.29 They also reported that remdesivir administered to mice before and after exposure to MERS-CoV significantly improved pulmonary function, reduced lung viral loads and reduced severity in lung pathology.
In the literature review 72 articles were found, of which two were clinical studies using remdesivir in the treatment of COVID-19. The first confirmed case of COVID-19 in the US reported the intravenous use of remdesivir on day six following hospitalization with worsening symptoms; there was significant improvement by day eight.30 More recently, 36 of 53 (68%) severely-ill COVID-19 patients given a ten day course of remdesivir (for compassionate use) showed significant improvement in the category of oxygen support.31 However, overall mortality rate from time of admission did not differ between patients receiving invasive ventilation compared to those not receiving non-invasive ventilation. Despite these findings the current level of evidence for remdesivir is low and rigorous clinical trials are needed to confirm these findings in larger patient populations. Therefore, at this time we recommend the use of remdesivir be restricted to the conduct of clinical trials. On 1st May 2020, the US Food and Drugs Administration authorized the emergency use of remdesivir for hospitalized COVID-19 patients.
Interferons
Interferons (IFNs) are naturally occurring proteins produced by the immune system and belong to three classes: α, β and γ. They augment host immune responses to viruses, bacteria and cancer cells. Coronaviruses have been shown to suppress the interferon response in hosts. Several studies reviewed the effects of interferons in combination with ribavirin. Several in vitro and in vivo studies have shown positive effects of IFNα and IFNβ on SARS-CoV and MERS-CoV.32-34 IFNs have been shown to have greatest efficacy as prophylaxis or early treatment following exposure in the laboratory setting.35
In the literature review 631 articles were found, of which three were clinical studies using interferons in the treatment of MERS and SARS-CoV. These retrospective clinical studies in patients with severe symptoms of MERS showed no benefit; small sample sizes and poor study design may have accounted for these findings.36-38 Additionally, there is a paucity of randomized controlled trials for the use of interferon monotherapy in other coronaviruses. The overall quality of evidence for the use of interferons in SARS and MERS is low. As there are no published clinical studies on interferon use in COVID-19, their use should be restricted to clinical trials.
Ribavirin
Ribavirin is a nucleoside analogue with direct activity against RNA viruses, suppressing viral RNA synthesis and mRNA capping. Ribavirin as monotherapy is not recommended for SARS-CoV and has not been studied in MERS-CoV.26 Ribavirin and interferon appear to have synergistic effects in vitro and in vivo studies.32-34
In the literature search 208 articles were found, of which three were clinical studies using interferons in the treatment of MERS and SARS-CoV. However, retrospective observational studies do not support synergistic effects of ribavirin and interferon in patients with severe symptoms of MERS.36, 37 The overall quality of the evidence for ribavirin in the treatment of SARS and MERS is low. As there are no published clinical studies on ribavirin use in COVID-19, their use should be restricted to clinical trials.
Corticosteroids
Corticosteroids (which include prednisolone, hydrocortisone, methylprednisolone and prednisone) suppress inflammation and dampen the immune response.
In the literature search 696 articles were found related to corticosteroid and influenza, of these ten selected clinical studies are discussed here. Two retrospective studies in hospitalized patients with confirmed influenza A (pH1N1) found that early use of corticosteroids was associated with increased risk of critical disease or death.39, 40 A prospective cohort study in 1846 ICU patients with severe influenza pneumonia found that corticosteroid use significantly increased mortality rate.41 This finding of increased mortality was also observed in a case-control study in 288 severely-ill patients with influenza A (H7N9) viral pneumonia; however, disaggregation of the results found that low-to-moderate doses of corticosteroids had no significant impact on mortality rate.42
A multi-centred observational study in 607 hospitalized patients with influenza A (H1N1) found that corticosteroid use significantly increased mortality and prolonged ventilator use.43 A retrospective database analysis of corticosteroid use among 2141 cases of influenza A (H1N1) found that these drugs (preferentially used in severe cases) significantly increased nosocomial infection rates with a non-statistical increase in mortality rate.44 A matched case-control study in 108 hospitalized influenza pH1N1 patients found that glucocorticoid use significantly increased the risk of worsening illness and mortality in patients treated prior to onset of symptoms of severe acute respiratory infection (SARI).45 Notably, symptom severity and mortality rates did not worsen when corticosteroids were given after the onset of symptoms of SARI. On the other hand, multicentre studies in ICU patients with H1N1 viral pneumonia found that corticosteroid use did not increase mortality.46-48 One systematic review and meta-analysis examined 6637 patients with influenza-related acute respiratory distress syndrome, across 19 studies.49 In this review corticosteroid use (mostly in severe cases) was associated with significantly higher rates of mortality and incidence of nosocomial infections.49
In the literature search 180 articles were found related to corticosteroid and MERS, of these two were clinical studies and are discussed here. A recent retrospective study in 314 symptomatic MERS patients found that corticosteroid use significantly increased mortality rate.50 On the other hand, a retrospective study in 309 critically-ill MERS patients found that although corticosteroid use had no effect on mortality rates, these drugs significantly reduced MERS viral clearance.51
In the literature search 157 articles were found related to corticosteroid and SARS, of these 3 were clinical studies are discussed here. A small retrospective study in 78 patients with SARS found that corticosteroid use more than doubled the incidence of adverse outcomes.52 On the other hand, a large retrospective study in Hong Kong which included 1313 patients with SARS found that crude death rate was lower in patients treated with corticosteroids compared to those not treated with corticosteroids (17.0% versus 28.3%).53 It should be noted that a disproportionately higher number of patients were given corticosteroids compared to those not given corticosteroids (90.5% versus 9.5%).
In another large retrospective study in 1291 SARS cases it was shown that corticosteroid use increased mortality rate (relative risk = 1.334), which was exacerbated by comorbidities.54 Initiation of corticosteroid use from day five to seven had the lowest risk of fatality and the authors concluded that an “appropriate dose and a right time of application (may) decrease the risk of death”.
The possible explanation for these negative effects may be that corticosteroids dampen immune responses needed to eliminate the virus. A dampened immune response may lead to delayed viral clearance and increased risk of progression to more severe respiratory injury and mortality.
In the literature search 33 articles were found related to corticosteroid and COVID-19, only one of was a clinical study which is discussed here. This small observational study in 31 patients with COVID-19 found that corticosteroid use was not associated with viral clearance time, length of hospitalization or duration of symptoms.55 However, this evidence from a single observation study is insufficient to make a firm recommendation on the use of corticosteroids in COVID-19. Furthermore, there is a debate between those against their use based on evidence from influenza, MERS and SARS56 and those advocating for cautious use of low-doses in a subset of critically ill patients.57 Based on the overwhelming evidence against the use of corticosteroids, we recommend avoidance or cautious use in critically and severely ill COVID-19 patients.
Tocilizumab
Several studies suggest that severe SARS-CoV-2 infection activates an extreme immune response which precipitates a “cytokine storm” with excessive production of granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukins (IL-6, IL-2, IL-7, IL-10) and other immune proteins.58-60 There is accumulating evidence that tocilizumab, a recombinant humanized anti-human IL-6 receptor monoclonal antibody used to treat rheumatoid arthritis, may be a potential treatment for COVID-19 induced cytokine storms.59, 61,62
In the literature search 43 articles were found related to tocilizumab and COVID-19, of these, six were clinical studies. These case reports and small observational studies reported that the use of tocilizumab, in addition to standard care, was effective treatment in patients to ameliorate the severe cytokine storm precipitated by COVID-19.59, 60, 63-66 However, these findings were from studies with poor methodological quality. Subsequently, the level of evidence is low and more robust clinical studies are needed to support the use of tocilizumab in the treatment of COVID-19 induced cytokine storms. Therefore, we recommend its use be restricted to clinical trials and probably to patients with confirmed cytokine storm.
Umifenovir (Arbidol)
Umifenovir is an indole-based, hydrophobic dual-acting direct antiviral and host-targeting agent which acts at several stages in the viral life cycle, including cell entry, attachment and replication. An in vitro study in cell cultures found that arbidol and arbidol mesylate were effective in suppressing early-stage replication of SARS-CoV virus, with arbidol mesylate being almost 5 times more effective than arbidol.67
In the literature search seven articles were found related to umifenovir and COVID-19, of these four were clinical studies. A retrospective study in 33 COVID-19 patients compared the efficacy of arbidol and LPV/r versus LPV/r alone over five to 21 days.22 After seven and 14 days of treatment, significantly more patients given the combination therapy had a negative nasopharyngeal swab.
At day seven, significantly more patients in the combination group showed improvement in CT chest scans. Another retrospective study in 66 patients evaluated a nine day follow-up after hospitalization with and without arbidol.68 Significantly more arbidol treated patients were discharged from hospital compared with those who were not. Additionally, the five patients who died in the study did not receive arbidol. It was concluded that arbidol improved discharge rate and decreased mortality rate. A small, non-randomized, controlled retrospective study in 81 mildly symptomatic COVID-19 patients found that arbidol did not reduce the rate of conversion to negative pharyngeal SARS-CoV-2 swab test, in one week or the time for disappearance of symptoms.69 Another study found that arbidol was more efficient at clearing SARS-CoV-2 than LPV/r over a 14 day period.70
Considering the low methodological quality of these clinical studies it was concluded that the use of arbidol be restricted to prospective, randomized controlled studies to determine its efficacy in COVID-19.
Favipiravir
Favipiravir is an anti-viral agent that selectively and potently inhibits RNA-dependent RNA polymerase of RNA viruses. We found 15 articles in the literature search, two of which were clinical studies for the use of favipiravir.
A small open-labelled, non-randomized study in 80 COVID-19 patients found that favipiravir had greater efficacy compared to LPV/r with significant improvement in chest imaging and viral clearance, with fewer adverse effects.71 A larger, randomized trial in 240 patients found that favipiravir was not superior to arbidol with similar rates of recovery at seven days post-diagnosis.72 However, favipiravir caused a significant reduction in time-to-relief from fever and cough. Although these studies provide promising results for favipiravir, the comparators (LPV/r and arbidol) are drugs not proven to be effective in the treatment of COVID-19. At this time, with the low level of evidence, we recommend that the use of favipiravir be restricted to the conduct of clinical trials.
Sofosbuvir
Sofosbuvir is a direct-acting antiviral against hepatitis C virus and inhibits RNA-dependent RNA polymerase. Elfiky reported a study using the AutoDock Vina software to identify drugs that would bind to SARS-CoV-2 RNA-dependent RNA polymerase and thereby predict antiviral activity73. Among other candidate drugs, it was found that sofosbuvir was tightly bound to SARS-CoV-2 RNA-dependent RNA polymerase which could possibly lead to viral eradication. There were no clinical studies which evaluated the efficacy of sofobuvir in COVID-19; therefore, there is no evidence to recommend its use.
Ivermectin
Ivermectin, is a broad spectrum anti-parasitic agent, and its anti-viral activity against SARS-CoV-2 was evaluated using in vitro cell culture.74 It was shown that a single dose had the ability to control viral replication within 24-48 hours by inducing a 5000-fold reduction in viral RNA at 48 hours. There were no clinical studies which evaluated the efficacy of ivermectin in COVID-19; therefore, there is no evidence to recommend its use.
Baricitinib, Ruxolitinib and Fedratinib
The search for drugs against COVID-19 also involved the use of artificial intelligence which use algorithms that could identify approved drugs that are targets and potential therapeutic agents for SARS-CoV-2. In this study, the proprietary artificial intelligence, BenevolentAI, identified the selective JAK inhibitors baricitinib, ruxolitinib and fedratinib as drugs that inhibited the endocytosis of SARS-CoV-2.75
These drugs possess potent anti-inflammatory properties and are approved for rheumatoid arthritis and myelofibrosis. Although upper respiratory tract infection is a common long-term side effect of these drugs the authors propose that their short term use in COVID-19 would have minimal risk. It was also suggested that these drugs could be used in combination with antivirals (such as LPV/r and remdesivir) to reduce viral infectivity, viral replication and dampen host immune response. However, there are no clinical studies which evaluated the efficacy of these drugs in COVID-19 and there is no evidence to recommend their use.
Ongoing Clinical Trials
With no approved drugs or vaccines for COVID-19, the race for discovery is on. As of 30th April 2020 there were over 600 registered clinical trials for drug use in COVID-19.76 Most of these trials would be conducted in countries hardest affected by COVID-19, in Asia, Europe and North America. On 20th March 2020, the WHO launched the SOLIDARITY TRIAL that would evaluate the efficacy of five of the more promising drug candidates (chloroquine, hydroxychloroquine, LPV/r, remdesivir and interferon β-1a) in several countries around the world. It is expected that findings of these studies would provide the robust evidence needed to use these drugs with confidence in the fight against COVID-19.77
Rational use of ibuprofen, ACE Inhibitors (ACEIs) and Angiotensin Receptor Blockers (ARBs) in COVID-19
Ibuprofen
There are concerns that NSAIDS may prolong illness and recurrence in acute respiratory tract infection.78 However, there is no data on the effect of NSAID use in COVID-19 patients. The use of ibuprofen in COVID-19 patients is not recommended against by WHO guidelines.79 However, the use of ibuprofen should be cautiously undertaken as there is overlap of the clinical picture with dengue fever in regions where it is endemic.80
ACEIs and ARBs
It was proposed that ACEIs and ARBs may be harmful in COVID-19 due to up-regulation of ACE 2 receptors, which is the gateway for entry of SARS-CoV-2 into the cell.81 ACEIs and ARBs are beneficial in diabetic and hypertensive patients and the European Society of Cardiology (ESC) and other international cardiology societies have all strongly recommended continuation of ACEIs and ARBs, even with confirmed diagnosis COVID-19.82
Conclusions
With the high infection and mortality rates of COVID-19 there is an urgent need to find therapeutic options within the shortest possible timeframe. Several drugs approved for other conditions and experimental drugs are coming to the forefront for consideration. Some of these drugs are available locally and regionally, but careful attention to the current clinical evidence must be given before initiating use in the treatment of COVID-19 patients.
Chloroquine and hydroxychloroquine are available for the treatment of malaria, lupus and rheumatoid arthritis, but these drugs carry a burden of cardiac toxicity, even in the short term. The unequivocal evidence for their use in the general public for the prevention and treatment of COVID-19 is still emerging, and the benefit-risk balance should be a major consideration for these drugs.
Lopinavir/ritonavir (LPV/r) is also available locally for the treatment of HIV and is a frontline drug in the WHO’s SOLIDARITY trial. However, the best available evidence suggests that LPV/r is no better than standard care and further studies are needed to confirm or refute these findings. In the meantime, it would be recommended that the use of LPV/r be restricted to clinical trials.
Remdesivir, an experimental antiviral drug first tested in Ebola, is probably the brightest hope in the therapeutic armament in the fight against COVID-19. The limited clinical evidence is encouraging and larger trials are underway; but, there are a few considerations to be noted. Being an experimental drug would mean severe restrictions to its access from the pharmaceutical company (Gilead); and even in an environment of scaled-up production the cost to the healthcare systems in low-income countries would be prohibitive.
Interferons (also locally available) and ribavirin are also being considered, but the evidence for their use in SARS and MERS is not very convincing. The overwhelming majority of clinical studies on corticosteroid use in influenza, SARS and MERS have shown deleterious effects in critically-ill patients, including increased mortality, and experts have warned against their use in COVID-19. Most of the other drugs (tocilizumab, arbidol and favipiravir) being considered have far less evidence and their use should be restricted to clinical trials.
With the emergence of evidence to support the use of drugs in COVID-19 it would be prudent in the meantime that patient management include supportive care, infection prevention and control measure, as well as a multidisciplinary team approach suitable for the level of care.
Authors’ contribution
Yuri Clement: Conceptualization, Supervision, Project administration, Methodology, Investigation (data collection & analysis), Writing – Original Draft, review & editing; Satish Jankie: Investigation (data collection & analysis), Writing – review and editing; Shalini Pooransingh: Conceptualisation, Methodology, Investigation (data collection & analysis), Writing (review & editing); Diana Ignacio: Conceptualization, Investigation (data collection & analysis), Writing (review & editing); Avril E. Reid: Investigation (data collection), Resources, Data Curation, Writing (review & editing); Shurla Sampson-Francis: Resources, Writing (review & editing), Project administration; Stanley Giddings: Investigation (data collection & analysis), Writing (review & editing); Harold Watson: Resources, Investigation (data collection & analysis), Writing (review & editing).
Acknowledgements
This review was conducted following a request by the Ministry of Health (MoH) in Trinidad and Tobago for a report that would provide evidence for decision-making in the use of drugs in treatment of COVID-19. Professor Terence Seemungal (Dean, Faculty of Medical Sciences, The University of the West Indies in Trinidad and Tobago) was instrumental in assembling the team (The Faculty of Medical Sciences COVID-19 Therapeutics Review Committee) to review the evidence and provide the Government of the Republic of Trinidad and Tobago with a report that would guide on therapeutic options. Professor Sureshwar Pandey was involved in the development of initial parts of the MoH report.
Funding
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
References
[1] Petrosillo N, Viceconte G, Ergonul O et al.. COVID-19, SARS and MERS: are they closely related? Clin Microbiol Infect. 2020; pii: S1198-743X(20)30171-3. https://doi: 10.1016/j.cmi.2020.03.026
[2] Johns Hopkins University & Medicine. Coronavirus Resource Center, https://coronavirus.jhu.edu/map.html; 2020 (Accessed 12/04/2020).
[3] U.S. Food and Drug Administration: Emergency Use Authorization,
https://www.fda.gov/emergency-preparedness-and-response/mcm-legal-regulatory-and-policy-framework/emergency-use-authorization#covidtherapeutics;2020 (Accessed 09/03/2020).
[4] Sterne JAC, Savović J, Page MJ et al. RoB 2: a revised tool for assessing risk of bias in randomised trials, BMJ 2019; 366: l4898.
[5] Sidhu A, Verdier-Pinard D, Fidock D. pfcrt mutations confer chloroquine resistance to Plasmodium falciparum malaria parasites. Science. 2002;298:210-3. https://doi.org/10.1126/science.1074045.
[6] Vincent MJ, Bergeron E, Benjannet S et al. Chloroquine is a potent inhibitor of SARS coronavirus infection and spread. Virol J 2005;2(1):69. https://doi:10.1186/1743-422X-2-69.
[7] Wang M, Cao R., Zhang L et al. Remdesivir and chloroquine effectively inhibit the recently emerged novel coronavirus (2019-nCoV) in vitro. Cell Res 2020;30(3):269-71. https://doi.org/10.1038/s41422-020-0282-0.
[8] Savarino A, Boelaert JR, Cassone A et al. Effects of chloroquine on viral infections: an old drug against today’s diseases. Lancet Infectious diseases. 2003; 3(11):722-7. https://doi.org/10.1016/S1473-3099(03)00806-5
[9] Yan Y, Zou Z, Sun Y et al. Anti-malaria drug chloroquine is highly effective in treating avian influenza A H5N1 virus infection in an animal model. Cell Res 2013; 23(2), 300–2. https://doi.org/10.1038/cr.2012.165.
[10] Paton NI, Lee L, Xu Y et al. Chloroquine for influenza prevention: a randomised, double-blind, placebo controlled trial. Lancet Infect Dis 2011; 11: 677–83. https://doi:10.1016/S1473-3099(11)70065-2.
[11] Millán-Oñate J, Millan W, Mendoza LA et al. Successful recovery of COVID-19 pneumonia in a patient from Colombia after receiving chloroquine and clarithromycin. Ann Clin Microbiol Antimicrob. 2020;19(1):16. doi: 10.1186/s12941-020-00358-y.
[12] Borba MGS, Val FFA, Sampaio VS et al. Effect of High vs Low Doses of Chloroquine Diphosphate as Adjunctive Therapy for Patients Hospitalized With Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection: A Randomized Clinical Trial. JAMA Netw Open. 2020; 24;3(4.23):e208857. doi: 10.1001/jamanetworkopen.2020.8857.
[13] McChesney EW. Animal toxicity and pharmacokinetics of hydroxychloroquine sulfate. Am J Med 1983;75(1):11-8.
[14] Yao X, Ye F, Zhang M et al. 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). Clin Infect Dis. 2020; pii: ciaa237. doi: 10.1093/cid/ciaa237.
[15] Giudicessi JR, Noseworthy PA, Friedman PA et al. Urgent Guidance for Navigating and Circumventing the QTc Prolonging and Torsadogenic Potential of Possible Pharmacotherapies for COVID-19. Mayo Clinic Proceedings. 2020. Pre-pub https://mayoclinicproceedings.org/pb/assets/raw/Health%20Advance/journals/jmcp/jmcp_covid19.pdf
[16] Chatre C, Roubille F, Vernhet H et al. Cardiac Complications Attributed to Chloroquine and Hydroxychloroquine: A Systematic Review of the Literature. Drug Saf 2018; 41(10):919-931.
[17] Chen Z, Hu J, Zhang Z, Jiang S et al. Efficacy of hydroxychloroquine in patients with COVID-19: results of a randomized clinical trial. medRxiv 2020. https://doi.org/10.1101/2020.03.22.20040758.
[18] Gautret P, Lagier J-C, Parola P et al. Hydroxychloroquine and azithromycin as a treatment of COVID-19: results of an open-label non-randomized clinical trial. Int J Antimicrob Agents 2020; 105949. https://doi: 10.1016/j.ijantimicag.2020.105949.
[19] US Food and Drugs Administration: Hydroxychloroquine or Chloroquine for COVID-19: Drug Safety Communication – FDA Cautions Against Use Outside of the Hospital Setting or a Clinical Trial Due to Risk of Heart Rhythm Problems. https://www.fda.gov/safety/medical-product-safety-information/hydroxychloroquine-or-chloroquine-covid-19-drug-safety-communication-fda-cautions-against-use (Accessed 28/04/2020).
[20] Corbett AH, Lim ML, Kashuba AD. Kaletra (lopinavir/ritonavir). Ann Pharmacother 2002;36(7-8):1193-203.
[21] Lim J, Jeon S, Shin HY et al. Case of the Index Patient Who Caused Tertiary Transmission of COVID-19 Infection in Korea: the Application of Lopinavir/Ritonavir for the Treatment of COVID-19 Infected Pneumonia Monitored by Quantitative RT-PCR. J Korean Med Sci 2020;35(6). doi: 10.3346/jkms.2020.35.e79.
[22] Deng L, Li C, Zeng Q et al. Arbidol combined with LPV/r versus LPV/r alone against Corona Virus Disease 2019: a retrospective cohort study. J Infect 2020; pii: S0163-4453(20)30113-4. https://doi.org/10.1016/j.jinf.2020.03.002.
[23] Liu F, Xu A, Zhang Y et al. Patients of COVID-19 may benefit from sustained lopinavir-combined regimen and the increase of eosinophil may predict the outcome of COVID-19 progression, Int J Infect Dis 2020; pii: S1201-9712(20)30132-6. https://doi.org/10.1016/j.ijid.2020.03.013.
[24] Cao B, Wang Y, Wen D et al. A trial of lopinavir–ritonavir in adults hospitalized with severe Covid-19. The New England Journal of Medicine. 2020. https://doi: 10.1056/NEJMoa2001282.
[25] Gordon CJ, Tchesnokov EP, Feng JY et al. The antiviral compound remdesivir potently inhibits RNA-dependent RNA polymerase from Middle East respiratory syndrome coronavirus. J Biol Chem. 2020; pii: jbc.AC120.013056. https://doi: 10.1074/jbc.AC120.013056.
[26] Tchesnokov EP, Feng JY, Porter DP et al. Mechanism of Inhibition of Ebola Virus RNA-Dependent RNA Polymerase by Remdesivir. Viruses. 2019;11(4):326. https://doi: 10.3390/v11040326.
[27] Mulangu S, Dodd LE, Davey RT Jr et al. A Randomized, Controlled Trial of Ebola Virus Disease Therapeutics. The New England Journal of Medicine. 2019;381(24):2293-2303. https://doi: 10.1056/NEJMoa1910993.
[28] Wang M, Cao R, Zhang L et al. Remdesivir and chloroquine effectively inhibit the recently emerged novel coronavirus (2019-nCoV) in vitro. Cell Res. 2020;30(3):269-271. doi: 10.1038/s41422-020-0282-0.
[29] Sheahan TP, Sims AC, Leist SR et al. Comparative therapeutic efficacy of remdesivir and combination lopinavir, ritonavir, and interferon beta against MERS-CoV. Nat Commun 2020;11(1):1-14. doi: 10.1038/s41467-019-13940-6.
[30] Holshue ML, DeBolt C, Lindquist S et al. First case of 2019 novel coronavirus in the United States. The New England Journal of Medicine. 2020; 382(10):929-936. https://www.nejm.org/doi/full/10.1056/NEJMoa2001191
[31] Grein J, Ohmagari N, Shin D et al. Compassionate Use of Remdesivir for Patients with Severe Covid-19, The New England Journal of Medicine. 2020. https://doi: 10.1056/NEJMoa2007016.
[32] Stockman LJ, Bellamy R, Garner P. SARS: Systematic review of treatment effects. PLoS Med 2006; 3(9): e343. https://doi: 10.1371/journal. pmed.0030343.
[33] Mo Y, Fisher D. A review of treatment modalities for Middle East Respiratory Syndrome. Journal of Antimicrobial Chemotherapy. 2016; 71: 2016;71(12):3340-50. https://doi:10.1093/jac/dkw338.
[34] Morgenstern B, Michaelis M, Baer PC et al. Ribavirin and interferon-beta synergistically inhibit SARS-associated coronavirus replication in animal and human cell lines. Biochem Biophys Res Commun. 2005;326(4):905-8.
[35] Falzarano D, de Wit E, Rasmussen AL et al. Treatment with interferon-α2b and ribavirin improves outcome in MERS-CoV-infected rhesus macaques. Nature Medicine. 2013;19(10):1313-7. https://doi: 10.1038/nm.3362.
[36] Al-Tawfiq JA, Momattin H, Dib J et al. Ribavirin and interferon therapy in patients infected with the Middle East respiratory syndrome coronavirus: an observational study. International Journal of Infectious Disease 2014;20:42-6. https://doi: 10.1016/j.ijid.2013.12.003.
[37] Arabi YM, Shalhoub S, Mandourah Y et al. Ribavirin and Interferon Therapy for Critically Ill Patients With Middle East Respiratory Syndrome: A Multicenter Observational Study. Clin Infect Dis 2019; pii: ciz544. https://doi: 10.1093/cid/ciz544.
[38] Zhao Z, Zhang F, Xu M et al. Description and clinical treatment of an early outbreak of severe acute respiratory syndrome (SARS) in Guangzhou, PR China. J Med Microbiol. 2003;52(Pt 8):715-720. doi: 10.1099/jmm.0.05320-0.
[39] Han K, Ma H, An X et al. Early use of glucocorticoids was a risk factor for critical disease and death from pH1N1 infection. Clin Infect Dis. 2011;53(4):326-33. doi: 10.1093/cid/cir398.
[40] Brun-Buisson C, Richard JC, Mercat A et al. REVA-SRLF A/H1N1v 2009 Registry Group. Early corticosteroids in severe influenza A/H1N1 pneumonia and acute respiratory distress syndrome. Am J Respir Crit Care Med. 2011;183(9):1200-6. doi: 10.1164/rccm.201101-0135OC.
[41] Moreno G, Rodríguez A, Reyes LF et al. Corticosteroid treatment in critically ill patients with severe influenza pneumonia: a propensity score matching study. Intensive Care Med. 2018;44(9):1470-1482. doi: 10.1007/s00134-018-5332-4.
[42] Cao B, Gao H, Zhou B et al. Adjuvant Corticosteroid Treatment in Adults With Influenza A (H7N9) Viral Pneumonia. Crit Care Med. 2016;44(6):e318-28. doi: 10.1097/CCM.0000000000001616.
[43] Delaney JW, Pinto R, Long J et al. Canadian Critical Care Trials Group H1N1 Collaborative. The influence of corticosteroid treatment on the outcome of influenza A(H1N1pdm09)-related critical illness. Crit Care 2016;20 (1):75. https://doi: 10.1186/s13054-016-1230-8.
[44] Li H, Yang SG, Gu L et al. National Influenza A(H1N1)pdm09 Clinical Investigation Group of China. Effect of low-to-moderate-dose corticosteroids on mortality of hospitalized adolescents and adults with influenza A(H1N1)pdm09 viral pneumonia. Influenza Other Respir Viruses. 2017;11(4):345-54. https://doi: 10.1111/irv.12456.
[45] Xing X, Hu S, Chen M et al. Severe acute respiratory infection risk following glucocorticosteroid treatment in uncomplicated influenza-like illness resulting from pH1N1 influenza infection: a case control study. BMC Infect Dis 2019;19(1):1-12. https://doi: 10.1186/s12879-019-4669-9.
[46] Diaz E, Martin-Loeches I, Canadell L et al. Corticosteroid therapy in patients with primary viral pneumonia due to pandemic (H1N1) 2009 influenza. J Infect. 2012;64(3):311-8. doi: 10.1016/j.jinf.2011.12.010. Epub 2012 Jan 2.
[47] Linko R, Pettilä V, Ruokonen E et al. Corticosteroid therapy in intensive care unit patients with PCR-confirmed influenza A(H1N1) infection in Finland. Acta Anaesthesiol Scand. 2011;55(8):971-9. doi: 10.1111/j.1399-6576.2011.02491.x.
[48] Martin-Loeches I, Lisboa T, Rhodes A et al. Use of early corticosteroid therapy on ICU admission in patients affected by severe pandemic (H1N1)v influenza A infection. Intensive Care Med. 2011;37(2):272-83. doi: 10.1007/s00134-010-2078-z. Epub 2010 Nov 24.
[49] Zhou W, Liu Y, Tian D et al. Potential benefits of precise corticosteroids therapy for severe 2019-nCoV pneumonia. Signal Transduct Target Ther. 2020;5:18. doi: 10.1038/s41392-020-0127-9.
[50] Alfaraj SH, Al-Tawfiq JA, Assiri AY et al. Clinical predictors of mortality of Middle East Respiratory Syndrome Coronavirus (MERS-CoV) infection: A cohort study. Travel Med Infect Dis. 2019;29:48-50. doi: 10.1016/j.tmaid.2019.03.004.
[51] Arabi YM, Mandourah Y, Al-Hameed F, Sindi AA et al. Saudi Critical Care Trial Group. Corticosteroid Therapy for Critically Ill Patients with Middle East Respiratory Syndrome. Am J Respir Crit Care Med 2018;197(6):757-67. https://doi: 10.1164/rccm.201706-1172OC.
[52] Auyeung TW, Lee JS, Lai WK et al. The use of corticosteroid as treatment in SARS was associated with adverse outcomes: a retrospective cohort study. J Infect. 2005;51(2):98-102.
[53] Yam LY, Lau AC, Lai FY et al. Corticosteroid treatment of severe acute respiratory syndrome in Hong Kong. J Infect. 2007;54(1):28-39.
[54] Li N, Wang GF, Wu YF et al. [Side effects of glucocorticosteroids in the management of 1291 patients of SARS]. Beijing Da Xue Xue Bao Yi Xue Ban. 2004;36(5):519-24.
[55] Zha L, Li S, Pan L et al. Corticosteroid treatment of patients with coronavirus disease 2019 (COVID-19). Med J Aust. 2020; Apr 8. doi: 10.5694/mja2.50577.
[56] Russell CD, Millar JE, Baillie JK. Clinical evidence does not support corticosteroid treatment for 2019-nCoV lung injury. The Lancet. 2020;395(10223):473-475. doi: 10.1016/S0140-6736(20)30317-2.
[57] Zhou Y, Fu X, Liu X et al. Use of corticosteroids in influenza-associated acute respiratory distress syndrome and severe pneumonia: a systemic review and meta-analysis. Sci Rep. 2020 Feb 20;10(1):3044. https://doi: 10.1038/s41598-020-59732-7.
[58] Mehta P, McAuley DF, Brown M et al. COVID-19: consider cytokine storm syndromes and immunosuppression. The Lancet. 2020 Mar 28;395(10229):1033-1034. https://doi: 10.1016/S0140-6736(20)30628-0.
[59] Xu X, Han M, Li T et al. Effective treatment of severe COVID-19 patients with tocilizumab. ChinaXiv. 2020;202003(00026):v
[60] Michot JM, Albiges L, Chaput N et al. Tocilizumab, an anti-IL6 receptor antibody, to treat Covid-19-related respiratory failure: a case report. Ann Onco 2020; pii: S0923-7534(20)36387-0. https://doi.org/10.1016/j.annonc.2020.03.300.
[61] Kaly L, Rosner I. Tocilizumab–A novel therapy for non-organ-specific autoimmune diseases. Best Pract Res Clin Rheumatol 2012;26(1):157-65. http://doi: 10.1016/j.berh.2012.01.001.
[62] Alten R, Maleitzke T. Tocilizumab: a novel humanized anti-interleukin 6 (IL-6) receptor antibody for the treatment of patients with non-RA systemic, inflammatory rheumatic diseases. Ann Med 2013;45(4):357-63. https://doi: 10.3109/07853890.2013.771986.
[63] Zhang X, Song K, Tong F et al. First case of COVID-19 in a patient with multiple myeloma successfully treated with tocilizumab. Blood Adv. 2020;4(7):1307-10. https://doi: 10.1182/bloodadvances.2020001907.
[64] Cellina M, Orsi M, Bombaci F et al. Favorable changes of CT findings in a patient with COVID-19 pneumonia after treatment with tocilizumab. Diagn Interv Imaging. 2020 Mar 31. pii: S2211-5684(20)30087-5. doi: 10.1016/j.diii.2020.03.010.
[65] Radbel J, Narayanan N, Bhatt PJ. Use of tocilizumab for COVID-19 infection-induced cytokine release syndrome: A cautionary case report. Chest. 2020 Apr 25. pii: S0012-3692(20)30764-9. doi: 10.1016/j.chest.2020.04.024.
[66] Luo P, Liu Y, Qiu L et al. Tocilizumab treatment in COVID-19: a single center experience. J Med Virol 2020. https://doi: 10.1002/jmv.2580.
[67] Khamitov RA, Loginova SIa, Shchukina VN et al. Antiviral activity of arbidol and its derivatives against the pathogen of severe acute respiratory syndrome in the cell cultures]. Vopr Virusol. 2008;53(4):9-13.
[68] Wang Z, Yang B, Li Q et al. Clinical features of 69 cases patients infected with 2019 novel coronavirus in Wuhan, China. Clin Infect Dis 2020. https://doi.org/10.1093/cid/ciaa272
[69] Lian N, Xie H, Lin S et al. Umifenovir treatment is not associated with improved outcomes in patients with coronavirus disease 2019: A retrospective study. Clin Microbiol Infect. 2020 Apr 25. pii: S1198-743X(20)30234-2. doi: 10.1016/j.cmi.2020.04.026.
[70] Zhu Z, Lu Z, Xu T et al. Arbidol monotherapy is superior to lopinavir/ritonavir in treating COVID-19. J Infect. 2020 Apr 10. pii: S0163-4453(20)30188-2. doi: 10.1016/j.jinf.2020.03.060.
[71] Cai, Q, Yang M, Liu D et al. (2020). Experimental Treatment with Favipiravir for COVID-19: An Open-Label Control Study. Engineering (Beijing) 2020 Mar 18. doi: 10.1016/j.eng.2020.03.007.
[72] Chen C, Zhang Y, Huang J et al. Favipiravir versus Arbidol for COVID-19: A Randomized Clinical Trial. medRxiv. April 15, 2020. doi: https://doi.org/10.1101/2020.03.17.20037432
[73] Elfiky AA. Anti-HCV, nucleotide inhibitors, repurposing against COVID-19. Life Sci 2020; 248:117477. https://doi.org/10.1016/j.lfs.2020.117477.
[74] Caly L, Druce JD, Catton MG et al. The FDA-approved Drug Ivermectin inhibits the replication of SARS-CoV-2 in vitro. Antiviral Res 2020; 104787. https://doi.org/10.1016/j.antiviral.2020.104787.
[75] Stebbing J, Phelan A, Griffin I et al. COVID-19: combining antiviral and anti-inflammatory treatments. The Lancet Infect Dis 2020; 20(4):400-2. https://doi.org/10.1016/S1473-3099(20)30132-8
[76] NIH: US National Library of Medicine, ClinicalTrials.gov. https://clinicaltrials.gov/; 2020 (Accessed 12/04/2020).
[77] WHO, WHO Director-General’s opening remarks at the media briefing on COVID-19. https://www.who.int/dg/speeches/detail/who-director-general-s-opening-remarks-at-the-media-briefing-on-covid-19—18-march-2020; 2020 (Accessed 12/04/2020).
[78] Day M. Covid-19: ibuprofen should not be used for managing symptoms, say doctors and scientists. BMJ 2020;368:m1086. https:// doi: 10.1136/bmj.m1086
[79] WHO twitter page: https://twitter.com/WHO/status/1240409217997189128; 2020 (Accessed 12/04/2020).
[80] Yan G, Lee CK, Lam LTM et al. (2020) Covert COVID-19 and false-positive dengue serology in Singapore. Lancet Infect Dis 2020; pii: S1473-3099(20)30158-4. https://doi.org/10.1016/S1473-3099(20)30158-4.
[81] Tseng CT, Huang C, Newman P et al. Severe acute respiratory syndrome coronavirus infection of mice transgenic for the human Angiotensin-converting enzyme 2 virus receptor. J Virol 2007;81(3):1162-73.
[82] European Society of Cardiology. Position Statement of the ESC Council on Hypertension on ACE – Inhibitors and Angiotensin Receptor Blockers. https:/www.escardio.org/Councils/Council-on-Hypertension-(CHT)/News/position-statement-of the-esc-council-on-hypertension-on-ace-inhibitors-and-ang?fbclid=lwAR1qYxXs90rs5XFJAolF3Z_WF7QQSobN_gqLS8zyYblpr6xagH5xFSK-Yg; 2020 (Accessed 12/04/2020).
