Adverse Drug Events Associated With Remdesivir in Real-World Hospitalized Patients With COVID-19, Including Vulnerable Populations: A Retrospective Multicenter Study

In silico studies to understand the interactions of flavonoid inhibitor with nsp12-RNA dependent RNA polymerase of SARS-CoV-2 and its homologs

Aim

COVID 19 continues to be a major health concern. RNA dependent RNA polymerase of SARS-CoV-2 which is crucial for replication is therefore a potential drug target.

Methodology

Based on experimental structures of RdRp from SARS-CoV-2, computational models were generated of its homologs from SARS-C o V-1, MERS and Bat. SARS CoV-2 RdRp was used for virtual screening at nucleotide binding site with molecule from COCONUT Natural Products database using Glide. Complexes with the top inhibitor molecule were modelled using Discovery Studio and Desmond suite of programs.

Results

SARS-CoV-2 RdRp has a minimum of 80 % sequence similarity with its homologs, with the secondary structural elements, catalytic residues and metal binding residues being conserved. Certain residue variations in SARS-CoV-2 RdRp seems to be responsible for the stability of the enzyme. Docking and simulation studies showed that a flavonoid molecule with Coconut ID: CNP0127177.0 (HHF318) has binding affinity in low nano-molar range against RdRp from SARS-CoV-2 which was comparable or better than currently used inhibitors. This affinity stems from cationic-π with Arg555, and π-stacking interactions with a nucleobase of RNA. Molecule also engages with other residues that are crucial for its functions. This flavonoid molecule has similar physio-chemical properties like ATP towards SARS-CoV-2 RdRp, and has low potency for human ATP binding proteins.

Conclusion

HHF318 is a potential inhibitor of SARS-CoV-2 RdRp with good potency, specificity and pharmacokinetic properties for it to be developed as a drug candidate for COVID19.

Effectiveness and Safety of Remdesivir for the Treatment of COVID-19 Patients with Liver Cirrhosis: A Retrospective Cohort Study

BACKGROUND

Patients with liver cirrhosis are at an increased risk of mortality from coronavirus disease 2019 (COVID-19). Remdesivir, an adenosine analog, exhibits activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and is thus recommended for inpatients with COVID-19. This study evaluated the effectiveness and safety of remdesivir in patients with COVID-19 and liver cirrhosis.

METHODS

This retrospective study was conducted using data from Taiwan's largest healthcare system. The study cohort comprised adult patients with COVID-19 and liver cirrhosis who visited our emergency department between April 2021 and September 2022. Remdesivir's adverse effects, including bradycardia, anemia, unstable glucose levels, and abnormal liver function test results, were recorded. Treatment outcomes were assessed in terms of hospitalization duration, mortality, intubation, and intensive care unit admission.

RESULTS

This study included 1368 patients with COVID-19 and liver cirrhosis, of whom 46 received remdesivir. Remdesivir recipients were older (66.5 vs. 62 years; p = 0.042) and had a higher rate of oxygen therapy use (56.52% vs. 32.22%; p = 0.001) than nonrecipients. Common adverse effects of remdesivir included lower heart rates (83 vs. 96 bpm; p < 0.001) and decreased hemoglobin levels (9.5 vs. 10.2 g/dL; p = 0.003) without fatal consequences. No statistically significant difference between remdesivir recipients and nonrecipients in hospitalization duration, intubation rates, or mortality rates was found.

CONCLUSIONS

Remdesivir is safe for treating COVID-19 in patients with liver cirrhosis. Although remdesivir recipients exhibited trends toward improved outcomes in our study, large-scale studies are required to confirm its efficacy in this population.

COVID-19-Induced Refractory Symptomatic Hypocalcemia in a Patient With Parathyroid Gland Reimplantation

Background: Several cases of severe hypocalcemia in the setting of COVID-19 have been reported. The proposed mechanisms include direct viral interaction with ACE2 receptors in the parathyroid gland, viral chelation of calcium, worsening hypovitaminosis D, critical illness leading to unbound fatty acids binding calcium, and inflammatory cytokines leading to PTH resistance. Given the life-threatening nature of hypocalcemia, this underrecognized phenomenon should be on the forefront of the clinician's attention. This case highlights a rare manifestation of COVID-19 and further complicated by the patient's reimplanted parathyroid gland. Presentation: A 73-year-old female with primary hyperparathyroidism status post parathyroidectomy with reimplantation in the left forearm presented with 4 days of viral syndrome, found to have tetany and Chvostek's sign on physical exam. Pertinent laboratory abnormalities included calcium 5.3 mg/dL, ionized calcium 0.44 mmol/L, magnesium 1.4 mg/dL, phosphorous 5.5 mg/dL, PTH 242 pg/mL, and 25-OH vitamin D 56 ng/mL. Chest CT revealed multifocal pneumonia consistent with positive COVID-19 testing. She was subsequently admitted to the ICU for severe, symptomatic hypocalcemia and was initiated on a continuous calcium infusion, remdesivir, baricitinib, and steroids. Tetany resolved after 9 g calcium repletion, and she was transferred to the medical floor with an ionized calcium of 0.83 mmol/L. On hospital day 3, repeat ionized calcium was 0.78 mmol/L despite ongoing repletion. Given the persistence of hypocalcemia, a repeat PTH level was obtained which remained high at 487 pg/mL, suggesting ongoing PTH interference in the setting of COVID-19. PTH was obtained from the right (nonimplanted) arm which was normal at 74 pg/mL. This indicated an appropriate PTH response from the reimplanted gland, and that ongoing hypocalcemia may be due to insufficient PTH function to maintain systemic calcium levels or a peripheral interference with PTH level. With continued calcium supplementation and treatment of COVID-19, the patient's calcium stabilized at 8.6 mg/dL. She was discharged on oral calcium supplementation with endocrinology follow-up. Conclusion: Acute hypocalcemia strongly correlates with a profound inflammatory response in COVID-19 patients. This case corroborates the cytokine/PTH hypothesis. This patient had a high PTH sampled near the reimplanted gland but an inappropriately normal PTH from the nonimplanted arm, indicating that direct viral interaction interfering with PTH release is an unlikely mechanism. This case represents a scenario where PTH can be sampled directly from the source and this type of model could aid in the process of determining the etiology of hypocalcemia in COVID-19.

Review of COVID-19 Therapeutics by Mechanism: From Discovery to Approval

The global research and pharmaceutical community rapidly mobilized to develop treatments for coronavirus disease 2019 (COVID-19). Existing treatments have been repurposed and new drugs have emerged. Here we summarize mechanisms and clinical trials of COVID-19 therapeutics approved or in development. Two reviewers, working independently, reviewed published data for approved COVID-19 vaccines and drugs, as well as developmental pipelines, using databases from the following organizations: United States Food and Drug Administration (US-FDA), European Medicines Agency (EMA), Japanese Pharmaceutical and Medical Devices Agency (PMDA), and ClinicalTrials.gov. In all, 387 drugs were found for initial review. After removing unrelated trials and drugs, 66 drugs were selected, including 17 approved drugs and 49 drugs under development. These drugs were classified into six categories: 1) drugs targeting the viral life cycle 2) Anti-severe acute respiratory syndrome coronavirus 2 Monoclonal Antibodies, 3) immunomodulators, 4) anti-coagulants, 5) COVID-19-induced neuropathy drugs, and 6) other therapeutics. Among the 49 drugs under development are the following: 6 drugs targeting the viral life cycle, 12 immunosuppression drugs, 2 immunostimulants, 2 HIF-PHD targeting drugs, 3 GM-CSF targeting drugs, 5 anti-coagulants, 2 COVID-19-induced neuropathy drugs, and 17 others. This review provides insight into mechanisms of action, properties, and indications for COVID-19 medications.