Convalescent plasma is a blood product believed to provide passive antibody therapy through the transmission of neutralizing viral antibodies. Convalescent plasma has been used for decades for different viral infections including the treatment of H1N1 influenza virus, polio, chicken pox, measles, SARS-CoV-1, and MERS-CoV.
On Aug. 23, 2020, the FDA issued an emergency use authorization for investigational convalescent plasma for the treatment of COVID-19 in hospitalized patients. The FDA recommends neutralizing antibodies of at least 1:160. However, such assays have not been widely available and titers in plasma have often not been assessed prior to infusion.
There is no current standard recommended dosing. Most study protocols infuse 1-2 units of convalescent plasma for persons with COVID-19.
There is insufficient data to recommend either for or against the use of convalescent plasma for the treatment of COVID-19. Existing data suggest that, if a benefit exists, convalescent plasma is most useful when given early and with a high titer of neutralizing antibodies.
The adverse effects of convalescent plasma is very similar to the receipt of other blood products, including allergic reactions to the plasma, transfusion-associated circulatory overload (TACO), transfusion-related acute lung injury (TRALI), and acquisition of infections, though the latter is rare because of the rigorous screening process.
Tocilizumab is a recombinant humanized monoclonal antibody that binds to interleukin (IL)-6 receptors. Tocilizumab is currently FDA approved for the treatment of severe or life-threatening cytokine release syndrome that is associated with chimeric antigen–receptor (CAR) T-cell therapy and for the treatment of rheumatologic disorders.
The interest in using tocilizumab to treat persons with COVID-19 is based on the observations that a subset of patients with COVID-19 develop a severe inflammatory response that can result in cytokine storm resulting in ARDS, multiorgan failure, and potentially death. Very high levels of IL-6 have been observed in these individuals, thereby suggesting IL-6 may play a central role in the acute clinical decompensation seen with severe COVID-19.
The optimal dosing of tocilizumab in patients with COVID-19 is not known. The FDA recommends dosing of tocilizumab for cytokine release syndrome should not exceed 800 mg. There is limited data about the potential benefit of tocilizumab in patients with COVID-19. The COVACTA trial showed no difference between tocilizumab and placebo in regard to mortality. The time to hospital discharge was shorter in patients treated with tocilizumab; however, the difference was not statistically significant.
Reported adverse effects of tocilizumab include increase in ALT and AST, increased risk of serious infections (especially tuberculosis and invasive fungal infections), reactivation of hepatitis B virus, and rare reports of gastrointestinal perforation.
Hydroxycholoroquine (HCQ) and its sister drug chloroquine, have been used for many decades as treatment for malaria and autoimmune diseases. HCQ gained widespread popularity in the early days of the COVID-19 pandemic when clinical studies showed that it had significant in vitro activity against SARS-CoV-2, which provided the rationale for its use in the treatment and prevention of COVID-19 infection.
It was the first drug that was authorized for emergency use by the FDA during the COVID-19 pandemic. However, On June 15, 2020, because of accumulating harmful data, the FDA revoked the emergency authorization use of HCQ as a COVID-19 treatment.
Randomized controlled trials showed that patients treated with HCQ experienced a longer hospital stay with increase in mortality rates and increased likelihood of being placed on mechanical ventilation. In addition, studies revealed an increase in QT prolongation in patients treated with HCQ, especially when coadministered with azithromycin, which can lead to torsades de pointes, ventricular tachycardia, and sudden cardiac death.
The IDSA and National Institutes of Health, both recommend against the use of hydroxychloroquine with or without azithromycin to treat COVID-19 because the harms outweigh the benefits, even if high quality RCTs were to become available in the future.
There have been experimental studies on other medications for the treatment of COVID-19, including losartan, amlodipine, ivermectin, famotidine, Anakinra, Bruton’s tyrosine kinase inhibitors such as ibrutinib, and Janus kinase inhibitors, such as tofacitinib. Additionally, a few supplements such as vitamin C, vitamin D, and zinc have been used in both inpatient and outpatient settings for COVID-19 treatment. Polyclonal antibodies are being investigated in phase 3 trials. However, the data is insufficient, and the effectiveness of these drugs is unknown. The COVID-19 treatment guidelines panel recommends against the use of these treatment modalities.
Dr Tiyouh is an infectious diseases physician at Keystone Health in Chambersburg, Pa. Dr. Tenneti completed medical school at Vydehi Institute of Medical Sciences and Research Centre in Karnataka, India, and is interested in pursuing internal medicine residency. Dr. Tirupathi is the medical director of Keystone Infectious Diseases/HIV in Chambersburg, Pa., and currently chair of infection prevention at Wellspan Chambersburg Hospital and Waynesboro (Pa.) Hospitals. Dr. Palabindala is hospital medicine division chief at the University of Mississippi Medical Center, Jackson, and a member of the editorial advisory board for The Hospitalist.
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