Hydroxychloroquine and Ivermectin for the Treatment of COVID-19 Infection


Background: In December 2019, patients with pneumonia secondary to a new subtype of Coronavirus (COVID-19) were identified in China. In a few weeks the virus spread and cases started practically all over the world. In February 2020, the WHO declared a pandemic. Severe symptoms have been found in patients mainly with comorbidities and over 50 years of age. At this time there is no proven therapeutic alternative. In vitro studies and observational experiences showed that antimalarial drugs (Chloroquine and hydroxychloroquine) had antiviral activity and increased viral clearance. Ivermectin, on the other hand, has been shown in vitro to reduce viral replication and in an observational cohort, greater viral clearance with promising clinical results. So far there is no standard of treatment and clinical trials are needed to find effective treatment alternatives. Objective: To evaluate the safety and efficacy of treatment with hydroxychloroquine and ivermectin for serious COVID-19 infections in no critical hospitalized patients. Material and methods: Randomized controlled trial of patients diagnosed with respiratory infection by COVID-19, who present criteria for hospitalization. Randomization will be performed to receive hydroxychloroquine at a dose of 400 mg every 12 hours for one day and then 200 mg every 12 hours, to complete a 5-day treatment schedule. Group 2: Ivermectin 12 mg every 24 hours for one day (less than 80 kg) or Ivermectin 18 mg every 24 hours for one day (greater than 80 kg) + placebo until the fifth day. Group 3: Placebo. Prior to randomization, the risk of cardiovascular complications determined by corrected QT interval, related to hydroxychloroquine intake will be assessed. If the patient is at high risk, the allocation will be to ivermectin only or to placebo in an independent randomization, if the risk is low, any of the three groups could be assigned. Outcomes: The primary outcome will be discharge from hospital for improvement. The safety outcomes will be requirement of mechanical intubation, septic shock or death. Viral clearance will also be evaluated by means of PCR, which will be taken on the 5th day after admission, day 14 and 21.

Full Title of Study: “Efficacy and Safety of Hydroxychloroquine and Ivermectin in Hospitalized no Critical Patients Secondary to COVID-19 Infection: Randomized Controlled Trial”

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: Randomized
    • Intervention Model: Parallel Assignment
    • Primary Purpose: Treatment
    • Masking: Double (Participant, Care Provider)
  • Study Primary Completion Date: August 30, 2020

Detailed Description

Background In late December 2019, the health authorities of the People's Republic of China reported several cases of pneumonia of unknown origin in Wuhan City, Hubei Province, China. On December 31, 2019, the Chinese Center for Disease Control and Prevention began etiological and epidemiological research on this disease. Three samples of bronchoalveolar lavage were taken from patients from the Jinyintan hospital in Wuhan and through various processes they came to identify a new coronavirus that they initially called on January 7, 2020 as: 2019-nCoV. On January 2020, the World Health Organization (WHO) made the first recommendations on the epidemiological surveillance of this new coronavirus.

On January 22, 2020, the first session of the Emergencies Committee was convened by WHO in Geneva, Switzerland and on January 30 Public Health Emergency of International Importance (ESPII) was declared to the 2019 outbreak.

On February 11, the International Committee on Virus Taxonomy made up of experts, based on the biology, species and type of virus isolated, names this new coronavirus as SARS-CoV-2 and responds to "Severe Acute Respiratory Syndrome Coronavirus 2 "(Severe Acute Respiratory Syndrome CoronaVirus 2 for its acronym in English), the WHO proposes that same day to call the disease caused by SARS-CoV-2 as COVID-19.

The first case reported in Latin America was in Brazil on February 26 and on the 28th of the same month, Mexico communicates its first confirmed case of the new coronavirus in a 35-year-old patient from a trip to Italy. Given the alarming levels of spread and severity of COVID-19, at a press conference on March 11, 2020, WHO Director-General Tedros Adhanom Ghebreyesus declares the SARS-CoV-2.5 outbreak as a pandemic.

IVERMECTIN The SARS-CoV-2 viral genome was rapidly sequenced to allow for a diagnostic test, epidemiological follow-up, and the development of preventive and therapeutic strategies, however, to date there is no evidence from clinical trials for any therapy that improves the evolution of patients suspected or confirmed with COVID-19.

New potential candidates for the treatment of this disease have emerged. A preclinical study showed that ivermectin, an FDA-approved antiparasitic drug, reduces the viral load of SARS-CoV-2 in vitro.

Ivermectin is a broad-spectrum antiparasitic that has shown antiviral activity against a broad group of viruses in recent years. It has been shown to inhibit the import of HIV viral integrase into the nucleus of human cells and also replication of the virus. It does something similar with other proteins of the SV40 virus and the dengue virus. It has also been shown to limit the infection of RNA viruses such as dengue, West Nile virus, Venezuelan equine encephalitis virus, and influenza virus. It has also been shown to be effective against DNA viruses such as pseudorabies of the mice. On the other hand, it has not been shown to be effective against the zika virus in mice, although this should be re-evaluated.

Studies on the SARS-CoV-1 coronavirus have revealed that the alpha/beta1 importin of the virus plays a role in infection in relation to intracellular signals of the capsid protein, which may have an impact on the division of host cells. Studies in cultures of infected cells show that ivermectin has a potent antiviral effect against SARS-CoV-2 and opens up hopeful expectations for using this antiparasitic in the early treatment of COVID-19 which is likely to help reduce the viral load, prevent progression to severe phase and limit person-to-person transmission. Therefore, the development of clinical protocols comparing it with other antivirals with alternate mechanisms of action is important and should be established as soon as possible.

In the study by Patel et al., Ivermectin was evaluated in a cohort of patients requiring invasive mechanical ventilation. In the ivermectin group, they were admitted to a dose of 150mcg/kg once they were intubated and observed a significant reduction in mortality, as well as significant reductions in the length of hospitalization and days in the intensive care unit.

Hydroxychloroquine Antimalarial drugs such as chloroquine (CQ) and hydroxychloroquine (HCQ) have been used for more than a century. They have been used not only for malaria but also in rheumatic conditions due to their anti-inflammatory properties and good safety profile. That is why, in the midst of a pandemic, the question of the use of antimalarials in the treatment and prophylaxis of covid-19 has been raised.

Kayaerts et al. demonstrated the inhibition of SARS-CoV by chloroquine in Vero E6 cells at different post-infection times. Vincent et al. demonstrated the dose-dependent inhibition effect of the virus on Vero E6 cells immediately after viral absorption and also 3 to 5 hours later. They also demonstrated that the cells pre-treated with CQ were refractory to the virus in addition to improving terminal glycosylation of the ACE2 receptor, decreasing the viral affinity for the receptor and also reducing the onset of infection. The above illustrates the possibility of using HCQ for prophylaxis or treatment against SARS-CoV. Due to the similarities of SARS-CoV-2 with the SARS virus, several studies have proposed the use of HCQ and CQ for management of the current pandemic.

Wang et al. tested the in vitro effect of several antivirals approved by the Food and Drug Administration (FDA) of the United States of America. Remdesivir showed blocking of viral infection after virus entry with an Effective Concentration of 50% (EC50) of 0.77 μM and a cytotoxic concentration of 50% (CC50) greater than 100μM. Chloroquine had an EC50 = 1.13μM, and a CC50 greater than 100μM and an EC90 of 6.9μM. Chloroquine was effective at the viral entry and post-entry level, while remdesivir was only effective at the post-entry level. The above suggests a possible use of CQ as a prophylactic for SARS-CoV-2.19 infection.

Yao et al. Also tested the effect of HCQ and CQ in vitro. They tested the pharmacological activity of chloroquine and hydroxychloroquine using Vero cells infected with SARS-CoV-2. Physiology-based pharmacokinetic models (PBPK) were implemented for both drugs separately integrating their in vitro data. Using PBPK models, hydroxychloroquine concentrations in the lung fluid were simulated under 5 different dosing regimens to explore the most effective regimen while considering the safety profile of the drug. In this study, it was found that HCQ (EC50 = 0.72 μM) is more potent than chloroquine (EC50 = 5.47 μM) in vitro. Based on the results of the PBPK models, a loading dose of 400 mg twice daily of orally administered hydroxychloroquine sulfate is recommended, followed by a maintenance dose of 200 mg twice daily for 4 days for infection by SARS-CoV-2, since it reached three times the potency of CQ phosphate when administered 500 mg twice a day 5 days in advance.

Gao et al. demonstrated the superiority of CQ over control treatment in more than 100 patients with respect to inhibition of exacerbation of pneumonia, improvement in lung imaging findings, promoting negative virus conversion and shortening the course of disease in more than 10 hospitals in China. Gautret et al. treated 20 patients with hydroxychloroquine and compared the results with 16 controls in France. They used PCR to measure viral load on days 3, 4, 5, and 6 post-inclusion. The treatment group had a higher mean age, but no gender difference was made between the two groups. Asymptomatic patients and patients with upper and lower respiratory tract infections were treated. They concluded that HCQ was effective in reducing viral load. The results on day 3 indicated that 50% of the patients treated with HCQ had a reduction in viral load (p = 0.005), on day 4 it showed a 60% reduction (p = 0.04) on day 5, a 65% reduction (p= 0.006) and on day 6, 70% of the patients showed a reduction in the viral load (p= 0.001). Furthermore, they described the synergistic effect of azithromycin when used in conjunction with HCQ to decrease viral load. Dual treatment showed a 100% decrease in viral load (p <0.001) for day 6, while hydroxychloroquine alone showed a 70% decrease.

In the recently published recommendations of the American Society for Infectious Diseases (IDSA) on April 11, 2020, it is established that in hospitalized patients with COVID-19, the use of HCQ / CQ should only be given in the context of a clinical trial.

The best evidence currently available has failed to demonstrate or exclude a beneficial effect of HCQ on the clinical progression of COVID-19, as inferred by radiological findings, or on viral clearance by means of PCR tests, although a somewhat higher proportion in the HCQ group experienced clinical improvement (RR: 1.47; 95% CI 1.02 – 2.11, p=0.04). However, the certainty in the evidence was rated as very low mainly due to small sample sizes, co-interventions, and risk of bias due to methodological limitations. Furthermore, the selected results should be considered indirect, since significant patient outcomes (eg, mortality, rate of progression to ARDS, and need for mechanical ventilation) were not available.

Studies evaluating the addition of azithromycin (AZ) to HCQ provided indirect comparisons of failure of virological clearance with historical controls. The observed risk of mortality among patients who received HCQ + AZ during the hospitalization was 3.4% (6/175 patients). However, an estimated mortality rate in an untreated cohort was not provided in the manuscript. Compared to the lack of viral clearance in historical controls (100% virological failure), 12 symptomatic patients were compared on day 5 or 6 of a separate hospital in France. Patients who received HCQ + AZ treatment experienced numerically fewer cases of virologic failure (43% combined virologic failure; 29/71 patients). There is very low certainty in this comparison of treatment effect, mainly due to very high risk selection bias, making any claims of effectiveness highly uncertain. Furthermore, relying on intermediate outcomes, such as viral clearance to determine important outcomes for the patient (including a reduction in the development of pneumonia, hospital or ICU admission, or the need for intubation) adds another layer of imprecision.

Finally, Barbosa et al conducted a comparative study of hospitalized adults with viral pneumonia secondary to SARS-CoV-2 during the last two weeks of March 2020. A group receiving HCQ and support measures against another group that only received support measures. The primary endpoints were the effect of hydroxychloroquine use on the need to increase respiratory support, change in lymphocyte count, and change in neutrophil-lymphocyte ratio. In this study, of 63 included patients, 32 were assigned to the HCQ arm. The administration of HCQ was associated with the need to increase the degree of ventilatory support compared to those who did not receive HCQ for 5 days (p = 0.013). The change in total lymphocytes in the HCQ group was not different from that in the group that only received support measures. These authors concluded that the use of HCQ tends to worsen the neutrophil / lymphocyte ratio compared to the group that only received supportive measures, in addition to the fact that the use of HCQ was found to increase the risk that the patient required ventilatory management with intubation.

Definition of the problem

Due to the high rate of spread of COVID-19 infection, associated with a high rate of hospitalization due to respiratory failure, empirical treatment of active agents in vitro has become a common practice.

Hydroxychloroquine and ivermectin have demonstrated viral inhibition in vitro and observational experiences have proposed them as potentially safe alternatives with clinical efficacy.

The proposed treatments have an adequate margin of safety, in addition to the fact that we have extensive clinical experience because they were previously used in humans to treat malaria, rheumatologic diseases, or parasitosis. Due to this, in conjunction with the urgent need to seek therapeutic alternatives, controlled studies are required without assuming efficacy.

Justification COVID-19 infection has collapsed health systems in industrialized countries due to the large number of patients requiring respiratory assistance. There is no standard treatment for the management of this infection and the focus has been on the already known life support and management of Adult Respiratory Failure Syndrome in critically ill patients. The treatments used empirically have an adequate safety profile due to the experience in other clinical settings. The use of these empirical alternatives should be based on clinical trials since efficacy and safety should not be assumed in the group of patients with COVID-19. The Miguel Hidalgo Centennial Hospital has been assigned as a hospitalization center for COVID-19 patients in Aguascalientes Mexico.


Treatment with hydroxychloroquine or Ivermectin will be superior to placebo, with a shorter hospital stay and a lower rate of complications (intubation, septic shock, or death).


  • Drug: Hydroxychloroquine
    • Hydroxychloroquine: 400 mg PO every 12 hours for one day. Subsequently 200 mg every 12 hours per 4 more days.
  • Drug: Ivermectin
    • Ivermectin 12 mg PO every 24 hours for one day (in case of weight less than 80 kg) or 18 mg PO every 24 hours for one day (in case of weight over 80 kg) Subsequently this group will take two tablets of placebo 12 hrs after ivermectin ingestion and then one tablet of placebo each 12 hrs per 4 more days.
  • Drug: Placebo
    • Two tablets of placebo PO every 12 hours for one day. Subsequently one tablet of placebo every 12 hours per 4 more days.

Arms, Groups and Cohorts

  • Experimental: Hospitalized patients with COVID-19 QTc < 500 mseg
    • Patients with confirmed COVID-19 infection by RT-qPCR SARS-CoV-2 or suspected by chest computed tomography with criteria of hospitalization because emergency medical criteria, with no need of critical care assistance. The risk of hydroxychloroquine complications will be assessed by QT corrected by Bazett formula. If QTc < 500 ms could be randomized to hydroxychloroquine, ivermectin or placebo.
  • Experimental: Hospitalized patients with COVID-19 infection with QTc >500ms
    • Patients with confirmed COVID-19 infection by RT-qPCR SARS-CoV-2 or suspected by chest computed tomography with criteria of hospitalization because emergency medical criteria, with no need of critical care assistance. The risk of hydroxychloroquine complications will be assessed by QT corrected by Bazett formula. If QTc > 500 ms could be randomized to ivermectin or placebo.

Clinical Trial Outcome Measures

Primary Measures

  • Mean days of hospital stay
    • Time Frame: Three months
    • Days from admission as a suspected case of COVID with hospitalization criteria until discharge
  • Rate of Respiratory deterioration, requirement of invasive mechanical ventilation or dead
    • Time Frame: Three months
    • Respiratory deterioration defined by respiratory rate > 25 per minute, requirement of high oxygen supply (FiO2 > 80% ) to maintain oxygen saturation > 90 %, invasive mechanical ventilation or dead.
  • Mean of oxygenation index delta
    • Time Frame: Three months
    • Daily delta of oxygenation index during the hospitalization

Secondary Measures

  • Mean time to viral PCR negativization
    • Time Frame: 5, 14, 21 and 28 days after the first positive PCR
    • Mean time to viral negativization of RT-qPCR SARS-CoV-2. Pre Specified time: 5, 14, 21 and 28 days after the first positive PCR.

Participating in This Clinical Trial

Inclusion Criteria

  • RT-qPCR SARS-CoV-2 positivity or chest computed Tomography with suspected COVID-19 pneumonia
  • Hospitalization by medical emergency staff criteria

Exclusion Criteria

  • Other confirmed viral active and acute infection

Gender Eligibility: All

Minimum Age: 16 Years

Maximum Age: 90 Years

Are Healthy Volunteers Accepted: No

Investigator Details

  • Lead Sponsor
    • Centenario Hospital Miguel Hidalgo
  • Provider of Information About this Clinical Study
    • Sponsor
  • Overall Contact(s)
    • Jose Manuel Arreola Guerra, MD, MSc, PhD, 4494632049, dr.jmag@gmail.com


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