Ivermectin and Nitazoxanide Combination Therapy for COVID-19

Research Background and Rationale

In December 2019, a new infectious respiratory disease emerged in Wuhan, Hubei province, China. An initial cluster of infections was linked to Huanan seafood market, potentially due to animal contact. Subsequently, human-to-human transmission occurred and the disease, now termed coronavirus disease 19 (COVID-19) rapidly spread within China and all over the world. A novel coronavirus, SARS-coronavirus 2 (SARS-CoV-2), which is closely related to SARS-CoV, was detected in patients and is believed to be the etiologic agent of the new lung disease. The causative agent of the current COVID-19 pandemic, SARS-CoV-2, is a single stranded positive sense RNA virus that is closely related to severe acute respiratory syndrome coronavirus (SARS-CoV).

Selected Drugs

Ivermectin has anti-parasitic effect along with anti-viral activity against a broad range of viruses in vitro. Ivermectin was identified as an inhibitor of interaction between the human immunodeficiency virus-1 (HIV-1) integrase protein (IN) and the importin (IMP) α/β1 heterodimer responsible for IN nuclear import. Ivermectin has since been confirmed to inhibit HIV-1 replication. Importantly, Ivermectin has been demonstrated to limit infection by RNA viruses such as West Nile Virus and influenza. This broad-spectrum activity is believed to be due to the reliance by many different RNA viruses on IMPα/β1 during infection. Ivermectin has similarly been shown to be effective against the DNA virus pseudorabies virus (PRV) both in vitro and in vivo. Finally, Ivermectin was the focus of a phase III clinical trial in Thailand against DENV infection, in which a single daily oral dose was observed to be safe and resulted in a significant reduction in serum levels of viral NS1 protein, but no change in viremia or clinical benefit was observed.

The causative agent of the current COVID-19 pandemic, SARS-CoV-2, is a single stranded positive sense RNA virus that is closely related to severe acute respiratory syndrome coronavirus (SARS-CoV). Studies on SARS-CoV proteins have revealed a potential role for IMPα/β1 during infection in signal-dependent nucleocytoplasmic shutting of the SARS-CoV nucleocapsid protein that may impact host cell division. In addition, the SARS-CoV accessory protein ORF6 has been shown to antagonize the antiviral activity of the STAT1 transcription factor by sequestering IMPα/β1 on the rough ER/Golgi membrane.

Taken together, these reports suggested that Ivermectin's nuclear transport inhibitory activity may be effective against SARS-CoV-2. Interestingly, it has been postulated that the FDA-approved drug Ivermectin inhibits the replication of SARS-CoV-2 in vitro whereas a single treatment was able to provoke approximately 5000-fold reduction in viral load within 48h. Ivermectin has an established safety profile for human use. Recent reviews and meta-analysis indicate that high dose Ivermectin has comparable safety as the standard low-dose treatment, although there is not enough evidence to make conclusion about the safety profile in pregnancy. In clinical setting, Ivermectin was the focus of a phase III clinical trial on patients with dengue viral infection in Thailand, in which a single daily dose (200 - 400 µg/kg once daily for 2 days in one arm and 200-400 µg/kg once daily for 3 days in the other arm) was found to be safe but did not produce any clinical benefit. In previous clinical study, one dose of Ivermectin 200 μg/kg or four doses of Ivermectin 200 μg/kg (given on days 1, 2, 15, and 16) for the treatment of non-disseminated strongyloidiasis were implicated. The author proposed that, multiple doses of Ivermectin did not show higher efficacy and was tolerated less than a single dose. A single dose should, therefore, be preferred for the treatment of non-disseminated strongyloidiasis.

Nitazoxanide is originally developed as an antiprotozoal agent and has a broad-spectrum antiviral activity undergoing development for the treatment of influenza and other viral respiratory infections. In addition to its antiviral activity, Nitazoxanide inhibits the production of pro-inflammatory cytokines TNFα, IL-2, IL-4, IL-5, IL-6, IL-8 and IL-10 in peripheral blood mononuclear cells. Nitazoxanide could improve outcomes in patients infected with MERS-CoV by suppressing overproduction of pro-inflammatory cytokines, including IL-6. Nitazoxanide has been tested in clinical setting for the treatment of acute uncomplicated influenza, where the subjects received either 600 or 300 mg of Nitazoxanide or placebo orally twice daily for five days and were followed for 28 days. Subjects who received Nitazoxanide 600 mg twice daily experienced shorter times to alleviation of symptoms compared with subjects who received 300 mg Nitazoxanide twice daily, which in turn, was shorter than placebo.

According to the National Health Commission of the People's Republic of China, there is lack of effective antiviral therapy against COVID-19. Nearly all patients who suffered from COVID-19-associated pneumonia accepted oxygen therapy and WHO recommended extracorporeal membrane oxygenation (ECMO) to patients with refractory hypoxemia. Rescue treatment with convalescent plasma and immunoglobulin G are delivered to some critical cases according to their condition.

The rationale of the use of Ivermectin and Nitazoxanide combination for treatment of COVID-19 infected patients is based on the antiviral and anti-inflammatory activity of the selected drugs. Since the two drugs exhibit different modes of action, it would be of value in containing the viral infection through targeting different sites in the pathophysiology of the disease.

Diagnostic criteria

The viral research institution in China has conducted preliminary identification of the SARS-CoV-2 through the classical Koch's postulates and observing its morphology through electron microscopy. So far, the golden clinical diagnosis method of COVID-19 is nucleic acid detection in the nasal and throat swab sampling or other respiratory tract samplings by real-time PCR and further confirmation by next-generation sequencing.

Common Side Effects of Ivermectin

* Itching and rash
* Swelling
* Headache
* Joint pain
* Pink eye, inflammation of the eyes or discomfort
* Dizziness and drop in blood pressure upon standing
* Racing heart beat
* Changes in liver function tests
* Serious Side Effects of Ivermectin (Generally with Ivermectin tablets)
* Severe skin reactions
* Seizures
* Asthma flare-up
* Changes in vision
* Sudden drop in blood pressure
* Dizziness upon standing
* Liver dysfunction
* Bleeding

Drug interactions of Ivermectin

1. Warfarin and Coumarin Ivermectin may decrease the anticoagulant activities of warfarin and 4-hydroxycoumarin
2. Albendazole The metabolism of Albendazole can be increased when combined with Ivermectin
3. Doxycyline

Additive pharmacodynamic effect

* Contraindication of Ivermectin
* Abnormal liver function tests
* Allergies towards Ivermectin
* Side effects of Nitazoxanide
* The most common adverse effects are GIT as nausea and occasional stomach cramps with mild diarrhea, reduced appetite and vomiting. Nervous system side effects as headache, dizziness, somnolence, insomnia, tremor, and hypesthesia have been reported in less than 1% of the patients.

Contraindications of Nitazoxanide

* There are no data on the excretion of Nitazoxanide into human milk. The manufacturer recommends that caution should be used when administering Nitazoxanide to nursing women.

Interactions of Nitazoxanide

* Tizoxanide (the active metabolite of Nitazoxanide) is highly bound to plasma protein (\> 99.9%). Therefore, it is necessary to monitor for adverse reactions when administering Nitazoxanide concurrently with other highly plasma protein-bound drugs with narrow therapeutic indices, as competition for binding sites may occur (e.g., warfarin).

Warning

* Nitazoxanide should be used with caution in patients with significant renal and hepatic impairment.

Research Objectives

The pandemic disease COVID-19 is particularly of major importance in Egypt where a heavy population lives. There is an acute need for comprehensive, continuous, and cost-effective health care delivery for infected people. Early detection and strategies for prevention of progression of COVID-19 would make a major difference for these patients and would also be economically beneficial for a resource-constrained country.

This research proposal was employed as a practical strategy for providing a suitable drug combination for possible treatment of COVID-19 infected patients. This drug combination may help to prevent the progression of respiratory complications. This can be achieved through different goals as follows:

1. Screening of different drugs related to different pharmacological classes depending on its possible activity against COVID-19 virus.
2. Providing cost-effective and easy-to-implement treatment strategy for infected patients and/or patients with high risk of developing respiratory failure.
3. Finally, this clinical strategy remains an important goal in improving Egyptian health state which can save people life and save a lot of money.

Scope of Work

The scope of work will be conducted through

1. Use of new drug combination of Ivermectin and Nitazoxanide for treatment of COVID-19 infected people. Since the two drugs exhibit different modes of action, it would be of value in containing the viral infection through targeting different sites in the pathophysiology of the disease.
2. Evaluation of the effect of new drug combination on the symptomatic treatment of COVID-19 patients according to WHO (Clinical management of severe acute respiratory infection (SARI) when COVID-19 disease is suspected) interim guidance published at 13 March 2020.
3. Investigating the impact of new drug combination on the prevention of severe compilations such as acute respiratory distress syndrome (ARDS).

Eligibility Criteria:
Inclusion Criteria:

* Adult symptomatic patients (18-65 years old), both sexes, and PCR positive in nasopharyngeal sample at admission.

Exclusion Criteria:

* Abnormal liver function (ALT, AST), chronic kidney disease or dialysis (CrCl\< 30 ml/min), immunocompromised patients taking medication upon screening, subjects on warfarin or dicumarol therapy and those with comorbid condition like hypertension, hypotension, cardiovascular disease, diabetes mellitus, asthma, COPD, seizures, coagulation disorder and malignancy.
* Patients will be also excluded if they had a known allergy to Ivermectin and/or Nitazoxanide, and those with contraindication towards the study medication.
* Pregnant women or women who are breastfeeding will be also excluded.