Combination Therapy with Fluoxetine and the Nucleoside Analog GS-441524 Exerts Synergistic Antiviral Effects against Different SARS-CoV-2 Variants In Vitro

Comparable Efficacy of Lopinavir/Ritonavir and Remdesivir in Reducing Viral Load and Shedding Duration in Patients with COVID-19

The spread of COVID-19 has significantly increased research on antiviral drugs and measures such as case isolation and contact tracing. This study compared the effects of lopinavir/ritonavir and remdesivir on COVID-19 patients with a control group receiving no antiviral drugs. Patients confirmed to have a SARS-CoV-2 infection via real-time RT-PCR were divided into three groups: lopinavir/ritonavir, remdesivir, and control. We assessed the efficacy of these drugs in reducing viral load and viral shedding duration using real-time RT-PCR and Vero E6 cell cultures. Lopinavir/ritonavir led to no detectable infectious SARS-CoV-2, with a median viral clearance time of one day, whereas one remdesivir-treated case remained culture-positive until day 12. Lopinavir/ritonavir significantly reduced viral load compared to remdesivir and control groups (p = 0.0117 and p = 0.0478). No infectious virus was detected in the lopinavir/ritonavir group, and the non-infectious SARS-CoV-2 proportion remained constant at 90%, higher than in the remdesivir and control groups (p = 0.0097). There was a significant difference in culture positivity among the groups (p = 0.0234), particularly between the lopinavir/ritonavir and remdesivir groups (p = 0.0267). These findings suggest that lopinavir/ritonavir reduces viral load and shortens the viral shedding duration compared to remdesivir, despite not being an effective treatment option.

Potent Dual Polymerase/Exonuclease Inhibitory Activities of Antioxidant Aminothiadiazoles Against the COVID-19 Omicron Virus: A Promising In Silico/In Vitro Repositioning Research Study

Recently, natural and synthetic nitrogenous heterocyclic antivirals topped the scene as first choices for the treatment of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections and their accompanying disease, the coronavirus disease 2019 (COVID-19). Meanwhile, the mysterious evolution of a new strain of SARS-CoV-2, the Omicron variant and its sublineages, caused a new defiance in the continual COVID-19 battle. Hitting the two principal coronaviral-2 multiplication enzymes RNA-dependent RNA polymerase (RdRp) and 3'-to-5' exoribonuclease (ExoN) synchronously using the same ligand is a highly effective novel dual pathway to hinder SARS-CoV-2 reproduction and stop COVID-19 progression irrespective of the SARS-CoV-2 variant type since RdRps and ExoNs are widely conserved among all SARS-CoV-2 strains. Herein, the present computational/biological study screened our previous small libraries of nitrogenous heterocyclic compounds, searching for the most ideal drug candidates predictably able to efficiently act through this double approach. Theoretical filtration gave rise to three promising antioxidant nitrogenous heterocyclic compounds of the 1,3,4-thiadiazole type, which are CoViTris2022, Taroxaz-26, and ChloViD2022. Further experimental evaluation proved for the first time, utilizing the in vitro anti-RdRp/ExoN and anti-SARS-CoV-2 bioassays, that ChloViD2022, CoViTris2022, and Taroxaz-26 could effectively inhibit the replication of the new virulent strains of SARS-CoV-2 with extremely minute in vitro anti-RdRp and anti-SARS-CoV-2 EC50 values of 0.17 and 0.41 μM for ChloViD2022, 0.21 and 0.69 μM for CoViTris2022, and 0.23 and 0.73 μM for Taroxaz-26, respectively, transcending the anti-COVID-19 drug molnupiravir. The preliminary in silico outcomes greatly supported these biochemical results, proposing that the three molecules potently strike the key catalytic pockets of the SARS-CoV-2 (Omicron variant) RdRp's and ExoN's vital active sites. Moreover, the idealistic pharmacophoric hallmarks of CoViTris2022, Taroxaz-26, and ChloViD2022 molecules relatively make them typical dual-action inhibitors of SARS-CoV-2 replication and proofreading, with their highly flexible structures open for various kinds of chemical derivatization. To cut it short, the present pivotal findings of this comprehensive work disclosed the promising repositioning potentials of the three 2-aminothiadiazoles, CoViTris2022, Taroxaz-26, and ChloViD2022, to successfully interfere with the crucial biological interactions of the coronaviral-2 polymerase/exoribonuclease with the four principal RNA nucleotides, and, as a result, cure COVID-19 infection, encouraging us to rapidly start the three drugs' broad preclinical/clinical anti-COVID-19 evaluations.

Drug-drug interactions between COVID-19 drug therapies and antidepressants

INTRODUCTION

Antidepressants are widely used for the pharmacological treatment of anxiety and mood disorders. Since the eruption of the SARS-COV-2 pandemic and the later development of targeted treatments against COVID-19, inevitably many patients receive antidepressants as well as targeted treatments against COVID-19 against COVID-19. Co-administration of antidepressants with COVID-19 therapeutics has the potential of drug-drug interactions, of varying severity and clinical significance.

AREAS COVERED

This is a curated narrative review of the current state of the art regarding drug-drug interactions between COVID-19 therapeutics and medications licensed for the pharmacotherapy of depression. A systematic search of electronic databases, using as keywords the international nonproprietaty names of currently approved COVID-19 therapeutics and antidepressants was performed, and additionally online interaction checker tools were consulted. Derived data were synthesized for each COVID-19 therapeutic and presented with up-to-date guidance.

EXPERT OPINION

Several COVID-19 therapeutics have potential for drug-drug interactions with antidepressants. Remdesivir and Nirmatrelvir-Ritonavir have the higher risk, whereas several monoclonal antibodies appear safer. The most serious drug-drug interactions (serotonin syndrome and QTc prolongation) require close monitoring; however, DDI toward reducing the efficacy of antidepressants may be difficult to recognize. As COVID-19 treatment protocols take precedence, psychiatrists should exert flexibility in antidepressant use and proactively monitor treatment progress.

Association of fluvoxamine with mortality and symptom resolution among inpatients with COVID-19 in Uganda: a prospective interventional open-label cohort study

Prior research suggests that fluvoxamine, a selective serotonin reuptake inhibitor (SSRI) used for the treatment of obsessive-compulsive disorder and major depressive disorder, could be repurposed against COVID-19. We undertook a prospective interventional open-label cohort study to evaluate the efficacy and tolerability of fluvoxamine among inpatients with laboratory-confirmed COVID-19 in Uganda. The main outcome was all-cause mortality. Secondary outcomes were hospital discharge and complete symptom resolution. We included 316 patients, of whom 94 received fluvoxamine in addition to standard care [median age, 60 years (IQR = 37.0); women, 52.2%]. Fluvoxamine use was significantly associated with reduced mortality [AHR = 0.32; 95% CI = 0.19-0.53; p < 0.001, NNT = 4.46] and with increased complete symptom resolution [AOR = 2.56; 95% CI = 1.53-5.51; p < 0.001, NNT = 4.44]. Sensitivity analyses yielded similar results. These effects did not significantly differ by clinical characteristic, including vaccination status. Among the 161 survivors, fluvoxamine was not significantly associated with time to hospital discharge [AHR 0.81, 95% CI (0.54-1.23), p = 0.32]. There was a trend toward greater side effects with fluvoxamine (7.45% versus 3.15%; SMD = 0.21; χ2 = 3.46, p = 0.06), most of which were light or mild in severity and none of which were serious. One hundred mg of fluvoxamine prescribed twice daily for 10 days was well tolerated and significantly associated with reduced mortality and with increased complete symptom resolution, without a significant increase in time to hospital discharge, among inpatients with COVID-19. Large-scale randomized trials are urgently needed to confirm these findings, especially for low- and middle-income countries, where access to vaccines and approved treatments against COVID-19 is limited.

Promising Experimental Anti-SARS-CoV-2 Agent "SLL-0197800": The Prospective Universal Inhibitory Properties against the Coming Versions of the Coronavirus

Isoquinoline derivatives having some nucleosidic structural features are considered as candidate choices for effective remediation of the different severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections and their following disease, the coronavirus disease 2019 (COVID-19). SLL-0197800 is a recently discovered isoquinoline compound with potential strong universal anticoronaviral activities against SARS-CoV-2 and its previous strains. SLL-0197800 nonspecifically hits the main protease (Mpro) enzyme of the different coronaviruses. Herein in the present study, we tested the probability of the previous findings of this experimental agent to be extended to comprise any coronavirus through concurrently disrupting the mutable-less replication enzymes like the RNA-dependent RNA polymerase (RdRp) protein as well as the 3'-to-5' exoribonuclease (ExoN) protein. The in vitro anti-RdRp/ExoN assay revealed the potent inhibitory activities of SLL-0197800 on the coronaviral replication with minute values of anti-RdRp and anti-RdRp/ExoN EC50 (about 0.16 and 0.27 μM, respectively). The preliminary in silico outcomes significantly supported these biochemical findings. To put it simply, the present important results of these extension efforts greatly reinforce and extend the SLL-0197800's preceding findings, showing that the restraining/blocking actions (i.e., inhibitory activities) of this novel investigational anti-SARS-CoV-2 agent against the Mpro protein could be significantly extended against other copying and multiplication enzymes such as RdRp and ExoN, highlighting the potential use of SLL-0197800 against the coming versions of the homicidal coronavirus (if any), i.e., revealing the probable nonspecific anticoronaviral features and qualities of this golden experimental drug against nearly any coronaviral strain, for instance, SARS-CoV-3.

Antipsychotic use and 28-day mortality in patients hospitalized with COVID-19: A multicenter observational retrospective study

Prior research has yielded conflicting results about the potential influence of antipsychotics in patients with COVID-19. In this multicenter retrospective study, we examined the association of antipsychotic use at admission with 28-day all-cause mortality in a sample of 59,021 adult patients hospitalized with COVID-19 from January 2020 to November 2021. In a 1:1 ratio matched analytic sample (N=1,454) accounting for age, sex, hospital, hospitalization period, the Elixhauser Comorbidity Index, other psychotropic medications, medications prescribed according to compassionate use or as part of a clinical trial, current diagnoses of psychiatric disorders, and clinical and biological markers of COVID-19 severity, antipsychotic use was not associated with 28-day mortality [23.5% (N=727) versus 18.6% (N=727); OR=1.16; 95%CI=0.89-1.51; p=0.280]. This association remained non-significant in exploratory analyses across all classes of antipsychotics and individual molecules, except for typical antipsychotics and loxapine, which were significantly linked to increased 28-day mortality, associations likely due to residual indication bias. Contrariwise, antipsychotics prescribed at daily doses higher than 200 mg of chlorpromazine-equivalents might be associated with reduced 28-day mortality when compared to patients not taking antipsychotics in the matched analytic sample [10.4% (N=154) versus 18.6% (N=727); AOR=0.56; 95%CI=0.31-0.96; p=0.040]. These results suggest that antipsychotic use, when prescribed at usual doses, are not be associated with 28-day mortality in patients hospitalized with COVID-19.

Drug-induced phospholipidosis is not correlated with the inhibition of SARS-CoV-2 - inhibition of SARS-CoV-2 is cell line-specific

Recently, Tummino et al. reported that 34 compounds, including Chloroquine and Fluoxetine, inhibit SARS-CoV-2 replication by inducing phospholipidosis, although Chloroquine failed to suppress viral replication in Calu-3 cells and patients. In contrast, Fluoxetine represses viral replication in human precision-cut lung slices (PCLS) and Calu-3 cells. Thus, it is unlikely that these compounds have similar mechanisms of action. Here, we analysed a subset of these compounds in the viral replication and phospholipidosis assays using the Calu-3 cells and PCLS as the patient-near system. Trimipramine and Chloroquine induced phospholipidosis but failed to inhibit SARS-CoV-2 replication in Calu-3 cells, which contradicts the reported findings and the proposed mechanism. Fluoxetine, only slightly induced phospholipidosis in Calu-3 cells but reduced viral replication by 2.7 orders of magnitude. Tilorone suppressed viral replication by 1.9 orders of magnitude in Calu-3 cells without causing phospholipidosis. Thus, induction of phospholipidosis is not correlated with the inhibition of SARS-CoV-2, and the compounds act via other mechanisms. However, we show that compounds, such as Amiodarone, Tamoxifen and Tilorone, with antiviral activity on Calu-3 cells, also inhibited viral replication in human PCLS. Our results indicate that antiviral assays against SARS-CoV-2 are cell-line specific. Data from Vero E6 can lead to non-transferable results, underlining the importance of an appropriate cell system for analysing antiviral compounds against SARS-CoV-2. We observed a correlation between the active compounds in Calu-3 cells and PCLS.

Medications Modulating the Acid Sphingomyelinase/Ceramide System and 28-Day Mortality among Patients with SARS-CoV-2: An Observational Study

Prior evidence indicates the potential central role of the acid sphingomyelinase (ASM)/ceramide system in the infection of cells with SARS-CoV-2. We conducted a multicenter retrospective observational study including 72,105 adult patients with laboratory-confirmed SARS-CoV-2 infection who were admitted to 36 AP-HP (Assistance Publique-Hôpitaux de Paris) hospitals from 2 May 2020 to 31 August 2022. We examined the association between the ongoing use of medications functionally inhibiting acid sphingomyelinase (FIASMA), which reduces the infection of cells with SARS-CoV-2 in vitro, upon hospital admission with 28-day all-cause mortality in a 1:1 ratio matched analytic sample based on clinical characteristics, disease severity and other medications (N = 9714). The univariate Cox regression model of the matched analytic sample showed that FIASMA medication use at admission was associated with significantly lower risks of 28-day mortality (HR = 0.80; 95% CI = 0.72-0.88; p < 0.001). In this multicenter observational study, the use of FIASMA medications was significantly and substantially associated with reduced 28-day mortality among adult patients hospitalized with COVID-19. These findings support the continuation of these medications during the treatment of SARS-CoV-2 infections. Randomized clinical trials (RCTs) are needed to confirm these results, starting with the molecules with the greatest effect size in the study, e.g., fluoxetine, escitalopram, and amlodipine.

Dual computational and biological assessment of some promising nucleoside analogs against the COVID-19-Omicron variant

Nucleoside analogs/derivatives (NAs/NDs) with potent antiviral activities are now deemed very convenient choices for the treatment of coronavirus disease 2019 (COVID-19) arisen by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. At the same time, the appearance of a new strain of SARS-CoV-2, the Omicron variant, necessitates multiplied efforts in fighting COVID-19. Counteracting the crucial SARS-CoV-2 enzymes RNA-dependent RNA polymerase (RdRp) and 3'-to-5' exoribonuclease (ExoN) jointly altogether using the same inhibitor is a quite successful new plan to demultiplicate SARS-CoV-2 particles and eliminate COVID-19 whatever the SARS-CoV-2 subtype is (due to the significant conservation nature of RdRps and ExoNs in the different SARS-CoV-2 strains). Successive in silico screening of known NAs finally disclosed six different promising NAs, which are riboprine/forodesine/tecadenoson/nelarabine/vidarabine/maribavir, respectively, that predictably can act through the planned dual-action mode. Further in vitro evaluations affirmed the anti-SARS-CoV-2/anti-COVID-19 potentials of these NAs, with riboprine and forodesine being at the top. The two NAs are able to effectively antagonize the replication of the new virulent SARS-CoV-2 strains with considerably minute in vitro anti-RdRp and anti-SARS-CoV-2 EC50 values of 189 and 408 nM for riboprine and 207 and 657 nM for forodesine, respectively, surpassing both remdesivir and the new anti-COVID-19 drug molnupiravir. Furthermore, the favorable structural characteristics of the two molecules qualify them for varied types of isosteric and analogistic chemical derivatization. In one word, the present important outcomes of this comprehensive dual study revealed the anticipating repurposing potentials of some known nucleosides, led by the two NAs riboprine and forodesine, to successfully discontinue the coronaviral-2 polymerase/exoribonuclease interactions with RNA nucleotides in the SARS-CoV-2 Omicron variant (BA.5 sublineage) and accordingly alleviate COVID-19 infections, motivating us to initiate the two drugs' diverse anti-COVID-19 pharmacological evaluations to add both of them betimes in the COVID-19 therapeutic protocols.

Acid sphingomyelinase (ASM) and COVID-19: A review of the potential use of ASM inhibitors against SARS-CoV-2

In the last 2 years, different pharmacological agents have been indicated as potential inhibitors of SARS-CoV-2 in vitro. Specifically, drugs termed as functional inhibitors of acid sphingomyelinase (FIASMAs) have proved to inhibit the SARS-CoV-2 replication using different types of cells. Those therapeutic agents share several chemical structure characteristics and some well-known representatives are fluoxetine, escitalopram, fluvoxamine, and others. Most of the FIASMAs are primarily used as effective therapeutic agents to treat different pathologies, therefore, they are natural drug candidates for repositioning strategy. In this review, we summarize the two main proposed mechanisms mediating acid sphingomyelinase (ASM) inhibition and how they can explain the inhibition of SARS-CoV-2 replication by FIASMAs. The first mechanism implies a disruption in the lysosomal pH fall as the endosome-lysosome moves toward the interior of the cell. In fact, changes in cholesterol levels in endosome-lysosome membranes, which are associated with ASM inhibition is thought to be mediated by lysosomal proton pump (ATP-ase) inactivation. The second mechanism involves the formation of an extracellular ceramide-rich domain, which is blocked by FIASMAs. The ceramide-rich domains are believed to facilitate the SARS-CoV-2 entrance into the host cells.

Novel Investigational Anti-SARS-CoV-2 Agent Ensitrelvir "S-217622": A Very Promising Potential Universal Broad-Spectrum Antiviral at the Therapeutic Frontline of Coronavirus Species

Lately, nitrogenous heterocyclic antivirals, such as nucleoside-like compounds, oxadiazoles, thiadiazoles, triazoles, quinolines, and isoquinolines, topped the therapeutic scene as promising agents of choice for the treatment of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections and their accompanying ailment, the coronavirus disease 2019 (COVID-19). At the same time, the continuous emergence of new strains of SARS-CoV-2, like the Omicron variant and its multiple sublineages, resulted in a new defiance in the enduring COVID-19 battle. Ensitrelvir (S-217622) is a newly discovered orally active noncovalent nonpeptidic agent with potential strong broad-spectrum anticoronaviral activities, exhibiting promising nanomolar potencies against the different SARS-CoV-2 variants. S-217622 effectively and nonspecifically hits the main protease (Mpro) enzyme of a broad scope of coronaviruses. Herein, in the present computational/biological study, we tried to extend these previous findings to prove the universal activities of this investigational agent against any coronavirus, irrespective of its type, through synchronously acting on most of its main unchanged replication enzymes/proteins, including (in addition to the Mpro), e.g., the highly conserved RNA-dependent RNA polymerase (RdRp) and 3'-to-5' exoribonuclease (ExoN). Biochemical evaluation proved, using the in vitro anti-RdRp/ExoN bioassay, that S-217622 can potently inhibit the replication of coronaviruses, including the new virulent strains of SARS-CoV-2, with extremely minute in vitro anti-RdRp and anti-RdRp/ExoN half-maximal effective concentration (EC50) values of 0.17 and 0.27 μM, respectively, transcending the anti-COVID-19 drug molnupiravir. The preliminary in silico results greatly supported these biochemical results, proposing that the S-217622 molecule strongly and stabilizingly strikes the key catalytic pockets of the SARS-CoV-2 RdRp's and ExoN's principal active sites predictably via the nucleoside analogism mode of anti-RNA action (since the S-217622 molecule can be considered as a uridine analog). Moreover, the idealistic druglikeness and pharmacokinetic characteristics of S-217622 make it ready for pharmaceutical formulation with the expected very good clinical behavior as a drug for the infections caused by coronaviruses, e.g., COVID-19. To cut it short, the current critical findings of this extension work significantly potentiate and extend the S-217622's previous in vitro/in vivo (preclinical) results since they showed that the striking inhibitory activities of this novel anti-SARS-CoV-2 agent on the Mpro could be extended to other replication enzymes like RdRp and ExoN, unveiling the possible universal use of the compound against the next versions of the virus (i.e., disclosing the nonspecific anticoronaviral properties of this compound against almost any coronavirus strain), e.g., SARS-CoV-3, and encouraging us to rapidly start the compound's vast clinical anti-COVID-19 evaluations.

Strong Dual Antipolymerase/Antiexonuclease Actions of Some Aminothiadiazole Antioxidants: A Promising In-Silico/In-Vitro Repurposing Research Study against the COVID-19 Omicron Virus (B.1.1.529.3 Lineage)

Currently, nitrogen-containing heterocyclic virucides take the lead as top options for treating the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections and their escorting disease, the coronavirus disease 2019 (COVID-19). But unfortunately, the sudden emergence of a new strain of SARS-CoV-2, the Omicron variant and its lineages, complicated matters in the incessant COVID-19 battle. Goaling the two paramount coronaviral-2 multiplication enzymes RNA-dependent RNA polymerase (RdRp) and 3'-to-5' exoribonuclease (ExoN) at synchronous times using single ligand is a quite effective new binary avenue to restrain SARS-CoV-2 reproduction and cease COVID-19 progression irrespective of the SARS-CoV-2 strain type, as RdRps and ExoNs are vastly conserved in all SARS-CoV-2 strains. The presented in-silico/in-vitro research winnowed our own small libraries of antioxidant nitrogenous heterocyclic compounds, inspecting for the utmost convenient drug candidates expectedly capable of effectively working through this dual tactic. Computational screening afforded three promising compounds of the antioxidant 1,3,4-thiadiazole class, which were named ChloViD2022, Taroxaz-26, and CoViTris2022. Subsequent biological examination, employing the in-vitro anti-RdRp/anti-ExoN and anti-SARS-CoV-2 assays, exclusively demonstrated that ChloViD2022, CoViTris2022, and Taroxaz-26 could efficiently block the replication of the new lineages of SARS-CoV-2 with considerably minute anti-RdRp and anti-SARS-CoV-2 EC50 values of about 0.18 and 0.44 μM for ChloViD2022, 0.22 and 0.72 μM for CoViTris2022, and 0.25 and 0.78 μM for Taroxaz-26, in the order, overtaking the standard anti-SARS-CoV-2 drug molnupiravir. These biochemical findings were optimally presupported by the results of the prior in-silico screening, suggesting that the three compounds might potently hit the catalytic active sites of the virus's RdRp and ExoN enzymes. Furthermore, the perfect pharmacophoric features of ChloViD2022, Taroxaz-26, and CoViTris2022 molecules make them typical dual inhibitors of SARS-CoV-2 replication and proofreading, with their relatively flexible structures eligible for diverse forms of chemical modification. In sum, the current important results of this thorough research work exposed the interesting repurposing potential of the three 2-amino-1,3,4-thiadiazole ligands, ChloViD2022, Taroxaz-26, and CoViTris2022, to effectively conflict with the vital biointeractions between the coronavirus's polymerase/exoribonuclease and the four essential RNA nucleotides, and, accordingly, arrest COVID-19 disease, persuading the relevant investigators to quickly begin the three agents' comprehensive preclinical and clinical anti-COVID-19 assessments.

Psychotropic drug repurposing for COVID-19: A Systematic Review and Meta-Analysis

Several psychotropic drugs, including antidepressants (AD), mood stabilizers, and antipsychotics (AP) have been suggested to have favorable effects in the treatment of COVID-19. The aim of this systematic review and meta-analysis was to collect evidence from studies concerning the scientific evidence for the repurposing of psychotropic drugs in COVID-19 treatment. Two independent authors searched PubMed-MEDLINE, Scopus, PsycINFO, and ClinicalTrials.gov databases, and reviewed the reference lists of articles for eligible articles published up to 13th December 2021. All computational, preclinical and clinical (observational and/or RCTs) studies on the effect of any psychotropic drug on Sars-CoV-2 or patients with COVID-19 were considered for inclusion. We conducted random effect meta-analyses on clinical studies reporting the effect of AD or AP on COVID-19 outcomes. 29 studies were included in the synthesis: 15 clinical, 9 preclinical, and 5 computational studies. 9 clinical studies could be included in the quantitative analyses. AD did not increase the risk of severe COVID-19 (RR= 1.71; CI 0.65-4.51) or mortality (RR=0.94; CI 0.81-1.09). Fluvoxamine was associated with a reduced risk of mortality for COVID-19 (OR=0.15; CI 0.02-0.95). AP increased the risk of severe COVID-19 (RR=3.66; CI 2.76-4.85) and mortality (OR=1.53; CI 1.15-2.03). Fluvoxamine might be a possible candidate for psychotropic drug repurposing in COVID-19 due to its anti-inflammatory and antiviral potential, while evidence on other AD is still controversial. Although AP are associated with worse COVID-19 outcomes, their use should be evaluated case to case and ongoing treatment with antipsychotics should be not discontinued in psychiatric patients.

Evaluation of a series of nucleoside analogs as effective anticoronaviral-2 drugs against the Omicron-B.1.1.529/BA.2 subvariant: A repurposing research study

Mysterious evolution of a new strain of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the Omicron variant, led to a new challenge in the persistent coronavirus disease 2019 (COVID-19) battle. Objecting the conserved SARS-CoV-2 enzymes RNA-dependent RNA polymerase (RdRp) and 3'-to-5' exoribonuclease (ExoN) together using one ligand is a successful new tactic to stop SARS-CoV-2 multiplication and COVID-19 progression. The current comprehensive study investigated most nucleoside analogs (NAs) libraries, searching for the most ideal drug candidates expectedly able to act through this double tactic. Gradual computational filtration afforded six different promising NAs, riboprine/forodesine/tecadenoson/nelarabine/vidarabine/maribavir. Further biological assessment proved that riboprine and forodesine are able to powerfully inhibit the replication of the new virulent strains of SARS-CoV-2 with extremely minute in vitro anti-RdRp and anti-SARS-CoV-2 EC50 values of about 0.21 and 0.45 μM for riboprine and about 0.23 and 0.70 μM for forodesine, respectively, surpassing both remdesivir and the new anti-COVID-19 drug molnupiravir. These biochemical findings were supported by the prior in silico data. Additionally, the ideal pharmacophoric features of riboprine and forodesine molecules render them typical dual-action inhibitors of SARS-CoV-2 replication and proofreading. These findings suggest that riboprine and forodesine could serve as prospective lead compounds against COVID-19. Graphical abstract.

Forodesine and Riboprine Exhibit Strong Anti-SARS-CoV-2 Repurposing Potential: In Silico and In Vitro Studies

Lately, nucleos(t)ide antivirals topped the scene as top options for the treatment of coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Targeting the two broadly conserved SARS-CoV-2 enzymes, RNA-dependent RNA polymerase (RdRp) and 3'-to-5' exoribonuclease (ExoN), together using only one shot is a very successful new tactic to stop SARS-CoV-2 multiplication irrespective of the SARS-CoV-2 variant type. Herein, the current studies investigated most nucleoside analogue (NA) libraries, searching for the ideal drug candidates expectedly able to act through this double tactic. Gradual computational filtration gave rise to six different promising NAs along with their corresponding triphosphate (TP) nucleotides. The subsequent biological assessment proved for the first time that, among the six NAs, riboprine and forodesine are able to hyperpotently inhibit the replication of the Omicron strain of SARS-CoV-2 with extremely low in vitro anti-RdRp, anti-ExoN, and anti-SARS-CoV-2 EC50 values of about 0.18, 0.28, and 0.40 μM for riboprine and about 0.20, 0.31, and 0.65 μM for forodesine, respectively, surpassing remdesivir and molnupiravir. The significant probability that both compounds may also act as prodrugs for their final TP nucleotides in vivo pushed us to examine the same activities for forodesine-TP and riboprine-TP. Both nucleotides similarly displayed very promising results, respectively, which are much better than those for the two reference TP nucleotides, GS-443902 and β-d-N4-hydroxycytidine 5'-TP (NHC-TP). The prior in silico data supported these biochemical findings, suggesting that riboprine and forodesine molecules and their expected active TP metabolites strongly hit the key catalytic pockets of the SARS-CoV-2 RdRp's and ExoN's main active sites. In brief, the current important results of this comprehensive study revealed the interesting repurposing potentials of, mainly, the two bioactive nucleosides forodesine and riboprine and their TP nucleotides to effectively shut down the polymerase/exoribonuclease-RNA nucleotide interactions of SARS-CoV-2 and consequently treat COVID-19 infections.

A Series of Adenosine Analogs as the First Efficacious Anti-SARS-CoV-2 Drugs against the B.1.1.529.4 Lineage: A Preclinical Repurposing Research Study

Given the rapid progression of the coronavirus disease 2019 (COVID-19) pandemic, an ultrafast response was urgently required to handle this major public crisis. To contain the pandemic, investments are required to develop diagnostic tests, prophylactic vaccines, and novel therapies. Lately, nucleoside analog (NA) antivirals topped the scene as top options for the treatment of COVID-19 caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. Meanwhile, the continuous generation of new lineages of the SARS-CoV-2 Omicron variant caused a new challenge in the persistent COVID-19 battle. Hitting the two crucial SARS-CoV-2 enzymes RNA-dependent RNA polymerase (RdRp) and 3'-to-5' exoribonuclease (ExoN) collectively together using only one single ligand is a very successful new approach to stop SARS-CoV-2 multiplication and combat COVID-19 irrespective of the SARS-CoV-2 variant type because RdRps and ExoNs are broadly conserved among all SARS-CoV-2 strains. Herein, the current comprehensive study investigated most NAs libraries, searching for the most ideal drug candidates expectedly able to perfectly act through this double tactic. Gradual computational filtration gave rise to six different promising NAs, which are riboprine, forodesine, tecadenoson, nelarabine, vidarabine, and maribavir, respectively. Further biological assessment proved for the first time, using the in vitro anti-RdRp/ExoN and anti-SARS-CoV-2 bioassays, that riboprine and forodesine, among all the six tested NAs, are able to powerfully inhibit the replication of the new virulent strains of SARS-CoV-2 with extremely minute in vitro anti-RdRp and anti-SARS-CoV-2 EC50 values of about 0.22 and 0.49 μM for riboprine and about 0.25 and 0.73 μM for forodesine, respectively, surpassing both remdesivir and the new anti-COVID-19 drug molnupiravir. The prior in silico data supported these biochemical findings, suggesting that riboprine and forodesine molecules strongly hit the key catalytic pockets of the SARS-CoV-2 (Omicron variant) RdRp's and ExoN's main active sites. Additionally, the ideal pharmacophoric features of riboprine and forodesine molecules render them typical dual-action inhibitors of SARS-CoV-2 replication and proofreading, with their relatively flexible structures open for diverse types of chemical derivatization. In Brief, the current important results of this comprehensive study revealed the interesting repurposing potentials of, mainly, the two nucleosides riboprine and forodesine to effectively shut down the polymerase/exoribonuclease-RNA nucleotides interactions of the SARS-CoV-2 Omicron variant and consequently treat COVID-19 infections, motivating us to rapidly begin the two drugs' broad preclinical/clinical anti-COVID-19 bioevaluations, hoping to combine both drugs soon in the COVID-19 treatment protocols.

Selective serotonin reuptake inhibitors: New hope in the fight against COVID-19

The emerging COVID-19 pandemic led to a dramatic increase in global mortality and morbidity rates. As in most infections, fatal complications of coronavirus affliction are triggered by an untrammeled host inflammatory response. Cytokine storms created by high levels of interleukin and other cytokines elucidate the pathology of severe COVID-19. In this respect, repurposing drugs that are already available and might exhibit anti-inflammatory effects have received significant attention. With the in vitro and clinical investigation of several studies on the effect of antidepressants on COVID-19 prognosis, previous data suggest that selective serotonin reuptake inhibitors (SSRIs) might be the new hope for the early treatment of severely afflicted patients. SSRIs' low cost and availability make them potentially eligible for COVID-19 repurposing. This review summarizes current achievements and literature about the connection between SSRIs administration and COVID-19 prognosis.

The Potential Protective Role of GS-441524, a Metabolite of the Prodrug Remdesivir, in Vaccine Breakthrough SARS-CoV-2 Infections

Cases of vaccine breakthrough, especially in variants of concern (VOCs) infections, are emerging in coronavirus disease (COVID-19). Due to mutations of structural proteins (SPs) (e.g., Spike proteins), increased transmissibility and risk of escaping from vaccine-induced immunity have been reported amongst the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Remdesivir was the first to be granted emergency use authorization but showed little impact on survival in patients with severe COVID-19. Remdesivir is a prodrug of the nucleoside analogue GS-441524 which is converted into the active nucleotide triphosphate to disrupt viral genome of the conserved non-structural proteins (NSPs) and thus block viral replication. GS-441524 exerts a number of pharmacological advantages over Remdesivir: (1) it needs fewer conversions for bioactivation to nucleotide triphosphate; (2) it requires only nucleoside kinase, while Remdesivir requires several hepato-renal enzymes, for bioactivation; (3) it is a smaller molecule and has a potency for aerosol and oral administration; (4) it is less toxic allowing higher pulmonary concentrations; (5) it is easier to be synthesized. The current article will focus on the discussion of interactions between GS-441524 and NSPs of VOCs to suggest potential application of GS-441524 in breakthrough SARS-CoV-2 infections.

Supplementary Information

The online version contains supplementary material available at 10.1007/s44231-022-00021-4.

Antiviral and Anti-Inflammatory Activities of Fluoxetine in a SARS-CoV-2 Infection Mouse Model

The coronavirus disease 2019 (COVID-19) pandemic continues to cause significant morbidity and mortality worldwide. Since a large portion of the world's population is currently unvaccinated or incompletely vaccinated and has limited access to approved treatments against COVID-19, there is an urgent need to continue research on treatment options, especially those at low cost and which are immediately available to patients, particularly in low- and middle-income countries. Prior in vitro and observational studies have shown that fluoxetine, possibly through its inhibitory effect on the acid sphingomyelinase/ceramide system, could be a promising antiviral and anti-inflammatory treatment against COVID-19. In this report, we evaluated the potential antiviral and anti-inflammatory activities of fluoxetine in a K18-hACE2 mouse model of SARS-CoV-2 infection, and against variants of concern in vitro, i.e., SARS-CoV-2 ancestral strain, Alpha B.1.1.7, Gamma P1, Delta B1.617 and Omicron BA.5. Fluoxetine, administrated after SARS-CoV-2 infection, significantly reduced lung tissue viral titres and expression of several inflammatory markers (i.e., IL-6, TNFα, CCL2 and CXCL10). It also inhibited the replication of all variants of concern in vitro. A modulation of the ceramide system in the lung tissues, as reflected by the increase in the ratio HexCer 16:0/Cer 16:0 in fluoxetine-treated mice, may contribute to explain these effects. Our findings demonstrate the antiviral and anti-inflammatory properties of fluoxetine in a K18-hACE2 mouse model of SARS-CoV-2 infection, and its in vitro antiviral activity against variants of concern, establishing fluoxetine as a very promising candidate for the prevention and treatment of SARS-CoV-2 infection and disease pathogenesis.

Antidepressant Use and Its Association with 28-Day Mortality in Inpatients with SARS-CoV-2: Support for the FIASMA Model against COVID-19

To reduce Coronavirus Disease 2019 (COVID-19)-related mortality and morbidity, widely available oral COVID-19 treatments are urgently needed. Certain antidepressants, such as fluvoxamine or fluoxetine, may be beneficial against COVID-19. We included 388,945 adult inpatients who tested positive for SARS-CoV-2 at 36 AP−HP (Assistance Publique−Hôpitaux de Paris) hospitals from 2 May 2020 to 2 November 2021. We compared the prevalence of antidepressant use at admission in a 1:1 ratio matched analytic sample with and without COVID-19 (N = 82,586), and assessed its association with 28-day all-cause mortality in a 1:1 ratio matched analytic sample of COVID-19 inpatients with and without antidepressant use at admission (N = 1482). Antidepressant use was significantly less prevalent in inpatients with COVID-19 than in a matched control group of inpatients without COVID-19 (1.9% versus 4.8%; Odds Ratio (OR) = 0.38; 95%CI = 0.35−0.41, p < 0.001). Antidepressant use was significantly associated with reduced 28-day mortality among COVID-19 inpatients (12.8% versus 21.2%; OR = 0.55; 95%CI = 0.41−0.72, p < 0.001), particularly at daily doses of at least 40 mg fluoxetine equivalents. Antidepressants with high FIASMA (Functional Inhibitors of Acid Sphingomyelinase) activity seem to drive both associations. These treatments may reduce SARS-CoV-2 infections and COVID-19-related mortality in inpatients, and may be appropriate for prophylaxis and/or COVID-19 therapy for outpatients or inpatients.

Remdesivir in treating hospitalized patients with COVID-19: A renewed review of clinical trials

Since December 2019, COVID-19 has spread across the world almost through 2.5 years. As of 16 June 2022, the cumulative number of confirmed cases of COVID-19 worldwide has reached 542.62 million, and the death toll has risen to 6.33 million. With the increasing number of deaths, it is urgent to find effective treatment drugs. Remdesivir, an investigational broad-spectrum antiviral drug produced by Gilead has been shown to inhibit SARS-CoV-2, in vitro and in vivo. This review is aimed to analyze the feasibility of remdesivir in COVID-19 and put forward the shortcomings of present clinical studies. We systematically searched PubMed and Web of Science up until 24 May 2022, using several specific terms such as “remdesivir” or “GS-5734” and “COVID-19” or “SARS-CoV-2” and retrieved basic researches and clinical studies of remdesivir in COVID-19. In this review, we summarized and reviewed the mechanism of remdesivir in SARS-COV-2, clinical trials of using remdesivir in COVID-19, analyzed the efficacy and safety of remdesivir, and judged whether the drug was effective for the treatment of COVID-19. In different clinical trials, remdesivir showed a mixed result in the treatment of COVID-19. It seemed that remdesivir shortened the time to recovery and had an acceptable safety profile. However, more clinical trials are needed to test the efficacy and safety of remdesivir.

The MEK1/2 Inhibitor ATR-002 (Zapnometinib) Synergistically Potentiates the Antiviral Effect of Direct-Acting Anti-SARS-CoV-2 Drugs

The coronavirus disease 2019 (COVID-19) represents a global public health burden. In addition to vaccination, safe and efficient antiviral treatment strategies to restrict the viral spread within the patient are urgently needed. An alternative approach to a single-drug therapy is the combinatory use of virus- and host-targeted antivirals, leading to a synergistic boost of the drugs’ impact. In this study, we investigated the property of the MEK1/2 inhibitor ATR-002’s (zapnometinib) ability to potentiate the effect of direct-acting antivirals (DAA) against SARS-CoV-2 on viral replication. Treatment combinations of ATR-002 with nucleoside inhibitors Molnupiravir and Remdesivir or 3C-like protease inhibitors Nirmatrelvir and Ritonavir, the ingredients of the drug Paxlovid, were examined in Calu-3 cells to evaluate the advantage of their combinatory use against a SARS-CoV-2 infection. Synergistic effects could be observed for all tested combinations of ATR-002 with DAAs, as calculated by four different reference models in a concentration range that was very well-tolerated by the cells. Our results show that ATR-002 has the potential to act synergistically in combination with direct-acting antivirals, allowing for a reduction in the effective concentrations of the individual drugs and reducing side effects.

3D ex vivo tissue platforms to investigate the early phases of influenza A virus- and SARS-CoV-2-induced respiratory diseases

Pandemic outbreaks of viruses such as influenza virus or SARS-CoV-2 are associated with high morbidity and mortality and thus pose a massive threat to global health and economics. Physiologically relevant models are needed to study the viral life cycle, describe the pathophysiological consequences of viral infection, and explore possible drug targets and treatment options. While simple cell culture-based models do not reflect the tissue environment and systemic responses, animal models are linked with huge direct and indirect costs and ethical questions. Ex vivo platforms based on tissue explants have been introduced as suitable platforms to bridge the gap between cell culture and animal models. We established a murine lung tissue explant platform for two respiratory viruses, influenza A virus (IAV) and SARS-CoV-2. We observed efficient viral replication, associated with the release of inflammatory cytokines and the induction of an antiviral interferon response, comparable to ex vivo infection in human lung explants. Endolysosomal entry could be confirmed as a potential host target for pharmacological intervention, and the potential repurposing potentials of fluoxetine and interferons for host-directed therapy previously seen in vitro could be recapitulated in the ex vivo model.

Efficacious Preclinical Repurposing of the Nucleoside Analogue Didanosine against COVID-19 Polymerase and Exonuclease

Analogues and derivatives of natural nucleosides/nucleotides are considered among the most successful bioactive species of drug-like compounds in modern medicinal chemistry, as they are well recognized for their diverse and efficient pharmacological activities in humans, especially as antivirals and antitumors. Coronavirus disease 2019 (COVID-19) is still almost incurable, with its infectious viral microbe, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), continuing to wreak devastation around the world. This global crisis pushed all involved scientists, including drug discoverers and clinical researchers, to try to find an effective and broad-spectrum anti-COVID-19 drug. Didanosine (2',3'-dideoxyinosine, DDI) is a synthetic inosine/adenosine/guanosine analogue and highly active antiretroviral therapeutic agent used for the treatment of human immunodeficiency virus infection and acquired immunodeficiency syndrome (HIV/AIDS). This potent reverse-transcriptase inhibitor is characterized by proven strong pharmacological effects against the viral genome, which may successfully take part in the effective treatment of SARS-CoV-2/COVID-19. Additionally, targeting the pivotal SARS-CoV-2 replication enzyme, RNA-dependent RNA polymerase (RdRp), is a very successful tactic to combat COVID-19 irrespective of the SARS-CoV-2 variant type because RdRps are broadly conserved among all SARS-CoV-2 strains. Herein, the current study proved for the first time, using the in vitro antiviral evaluation, that DDI is capable of potently inhibiting the replication of the novel virulent progenies of SARS-CoV-2 with quite tiny in vitro anti-SARS-CoV-2 and anti-RdRp EC50 values of around 3.1 and 0.19 μM, respectively, surpassing remdesivir together with its active metabolite (GS-441524). Thereafter, the in silico computational interpretation of the biological results supported that DDI strongly targets the key pocket of the SARS-CoV-2 RdRp main catalytic active site. The ideal pharmacophoric characteristics of the ligand DDI make it a typical inhibiting agent of SARS-CoV-2 multiplication processes (including high-fidelity proofreading), with its elastic structure open for many kinds of derivatization. In brief, the present results further uphold and propose the repurposing potentials of DDI against the different types of COVID-19 and convincingly motivate us to quickly launch its extensive preclinical/clinical pharmacological evaluations, hoping to combine it in the COVID-19 therapeutic protocols soon.

Remdesivir and Its Combination With Repurposed Drugs as COVID-19 Therapeutics

The SARS-CoV-2 virus needs multiple copies for its multiplication using an enzyme RNA-dependent RNA polymerase (RdRp). Remdesivir inhibits viral RdRp, controls the multiplication of the virus, and protects patients. However, treatment of COVID-19 with remdesivir involves adverse effects. Many ongoing clinical trials are exploring the potential of the combination of remdesivir with repurposed drugs by targeting multiple targets of virus and host human simultaneously. Better results were obtained with the remdesivir–baricitinib combination treatment for COVID-19 compared to the treatment with remdesivir alone. Notably, recovery from COVID-19 was found to be 8 days less via the remdesivir–baricitinib combination treatment as compared to remdesivir treatment alone. Furthermore, the mortality rate via the remdesivir–baricitinib combination treatment was lower compared to the remdesivir-only treatment. Remdesivir targets the SARS-CoV-2 enzyme while baricitinib targets the host human enzyme. Simultaneously, remdesivir and baricitinib as a combination inhibit their target viral RdRp and human Janus kinase, respectively. Ongoing trials for the combination of drugs will suggest in the future whether they may reduce the recovery time, reduce the mortality rate, and improve patient clinical status for noninvasive ventilation. In the future, simultaneously targeting virus replication enzymes and host human kinases may be the strategy for SARS-CoV-2 therapeutics.

COVID-19 Outcomes: Does the Use of Psychotropic Drugs Make a Difference? Accumulating Evidence of a Beneficial Effect of Antidepressants-A Scoping Review

PURPOSE/BACKGROUND

Studies for repurposed drugs in severe acute respiratory syndrome coronavirus type 2-infected and coronavirus disease 2019 (COVID-19) patients are ongoing. According to preclinical research, antidepressants (ADs) might be useful in the treatment of COVID-19.

METHODS/PROCEDURES

We conducted a scoping review including clinical studies on AD effects on SARS-CoV-2 infection and COVID-19.

FINDING/RESULTS

As of January 2, 2022, we found 14 clinical studies, which could be included into this review. Among them, there were 2 randomized, placebo-controlled studies and 2 prospective parallel-group studies about the efficacy/effectiveness and tolerability of fluvoxamine. The remaining studies were mainly retrospective studies considering COVID-19 hospital populations predominantly exposed to fluoxetine (N = 3), other selective serotonin reuptake inhibitors (SSRI), selective norepinephrine reuptake inhibitors (SNRI), and trazodone. The vast majority were hospital studies and assessed COVID-19 severity (morbidity) and mortality as primary endpoints. The only outpatient study (fluvoxamine) investigated the COVID-19-related hospitalization rate, and 1 psychiatric hospital study (SSRI, SNRI, trazodone) focused on the SARS-CoV-2 infection rate.

IMPLICATIONS/CONCLUSIONS

At present, the best evidence of an "anti-COVID-19" potential of ADs exists for fluvoxamine and, to a lesser extent, for fluoxetine. Preliminary evidence had found that patients exposed to SSRI or SNRI substance classes might have a reduced mortality risk and that trazodone might reduce SARS-CoV-2 infection rates. Three studies found no relevant influence of ADs on COVID-19 morbidity and mortality, and 1 study described increased mortality. The latter study, however, did not differentiate between psychotropic medication and ADs. Tricyclics and monoamine oxidase inhibitors are still absolute "dark zones" in COVID-19 research. Further controlled studies testing the effectiveness/efficacy and tolerability/safety (as well as the treatment timing and duration) of different AD substance classes in COVID-19 and post/long-COVID patients of various populations are warranted.

Potential Role of the Antidepressants Fluoxetine and Fluvoxamine in the Treatment of COVID-19

Mapping non-canonical cellular pathways affected by approved medications can accelerate drug repurposing efforts, which are crucial in situations with a global impact such as the COVID-19 pandemic. Fluoxetine and fluvoxamine are well-established and widely-used antidepressive agents that act as serotonin reuptake inhibitors (SSRI-s). Interestingly, these drugs have been reported earlier to act as lysosomotropic agents, inhibitors of acid sphingomyelinase in the lysosomes, and as ligands of sigma-1 receptors, mechanisms that might be used to fight severe outcomes of COVID-19. In certain cases, these drugs were administered for selected COVID-19 patients because of their antidepressive effects, while in other cases, clinical studies were performed to assess the effect of these drugs on treating COVID-19 patients. Clinical studies produced promising data that encourage the further investigation of fluoxetine and fluvoxamine regarding their use in COVID-19. In this review, we summarize experimental data and the results of the performed clinical studies. We also provide an overview of previous knowledge on the tissue distribution of these drugs and by integrating this information with the published experimental results, we highlight the real opportunity of using these drugs in our fight against COVID-19.

Association of Amlodipine with the Risk of In-Hospital Death in Patients with COVID-19 and Hypertension: A Reanalysis on 184 COVID-19 Patients with Hypertension

Association between calcium channel blockers (CCBs) or functional inhibitors of acid sphingomyelinase (FIASMAs) use and decreased mortality in people with COVID-19 has been reported in recent studies. Since amlodipine is both a CCB and a FIASMA, the aim of this study was to investigate the association between chronic amlodipine use and the survival of people with hypertension infected with COVID-19. This retrospective cohort study used data extracted from the medical records of adult inpatients with hypertension and laboratory-confirmed COVID-19 between 1 March 2020 and 31 August 2020 with definite outcomes (discharged from hospital or deceased) from Erasme Hospital (Brussels, Belgium). We re-analyzed the data of the retrospective cohort study using only the 184 patients (103 males, 81 females) with a mean age of 69.54 years (SD = 14.6) with hypertension. The fifty-five participants (29.9%) receiving a chronic prescription of amlodipine were compared with the 129 patients who did not receive a chronic prescription of amlodipine. Univariate and multivariate logistic regressions were used to explore the relationships between mortality and sex, age, comorbidities, smoking, and amlodipine status. Out of the 184 participants, 132 (71.7%) survived and 52 (28.3%) died. The mortality rates were, respectively, 12.73% (n = 7) and 34.88% (n = 45) for the amlodipine and non-amlodipine groups. Multivariate logistic regression was significant (Chi square (5) = 29.11; p < 0.0001). Chronic kidney disease and malignant neoplasm were significant predictors as well as amlodipine status. For chronic kidney disease and malignant neoplasm, the odds ratio with 95% confidence interval (95% CI) were, respectively, 2.16 (95% CI: 1.04−4.5; p = 0.039) and 2.46 (95% CI: 1.01−6.01; p = 0.047). For amlodipine status the odds ratio was 0.29 (95% CI: 0.11−0.74; p = 0.009). The result of the present study suggests that amlodipine may be associated with reduced mortality in people with hypertension infected with COVID-19. Further research and randomized clinical trials are needed to confirm the potential protective effect of amlodipine in people with hypertension infected with COVID-19.

Difficulty in Repurposing Selective Serotonin Reuptake Inhibitors and Other Antidepressants with Functional Inhibition of Acid Sphingomyelinase in COVID-19 Infection

The rapid spread of COVID-19 has become a health emergency causing an urgent need for drug treatments to control the outbreak, especially in more vulnerable individuals. This is reinforced by the fact that prophylactic vaccines and neutralizing monoclonal antibodies may not be fully effective against emerging variants. Despite all efforts made by the scientific community, efficient therapeutic options currently remain scarce, either in the initial, as well as in the advanced forms of the disease. From retrospective observational studies and prospective clinical trials, selective serotonin reuptake inhibitors (SSRIs), and other antidepressants with functional inhibition of acid sphingomyelinase (FIASMAs), have emerged as potential treatments of COVID-19. This has led to some prematurely optimistic points of view, promoting a large prescription of fluvoxamine in patients with COVID-19, that we think should be reasonably tempered.

Differential Molecular Responses of Zebrafish Larvae to Fluoxetine and Norfluoxetine

The occurrence of psychopharmaceuticals in aquatic ecosystems is a growing problem. Fluoxetine (FL) and its metabolite norfluoxetine (NF) are selective serotonin reuptake inhibitors. Although they may be potentially harmful to non-target species, available knowledge on the effects of NF is sparse, relative to FL. This study aimed at contributing to the body of knowledge about the modes-of-action (MoA) of these compounds and their underlying mechanisms eliciting hazardous effects during the early development of the teleost model zebrafish (Danio rerio). One hour post-fertilisation (hpf), embryos were exposed up to 80 hpf to these compounds at levels found in surface waters and higher (FL, 0.0015 and 0.05 µM; NF, 0.00006 and 0.0014 µM). Developmental anomalies were observed at 8, 32 and 80 hpf. Larvae were collected at 80 hpf to assess the expression of 34 genes related to FL and NF MoA and metabolism, using qPCR (quantitative reverse transcription PCR). Results showed that both compounds elicited an increased frequency of embryos exhibiting abnormal pigmentation, relative to controls. Gene expression alterations were more pronounced in FL- than in NF-exposed larvae. Cluster Analysis revealed two groups of genes discriminating between the drugs. for their marked opposing responses. Globally, downregulation of gene expression was typical of FL, whilst upregulation or no alteration was found for NF. These clusters identified were linked to the adrenergic pathway and to the retinoid and peroxisome proliferator-activated nuclear receptors. Overall, our data contradict the prevailing notion that NF is more toxic than FL and unveiled the expression levels of genes drd2b, 5-ht2c and abcc2 as possible markers of exposure to FL.

Potent Inhibitory Activities of the Adenosine Analogue Cordycepin on SARS-CoV-2 Replication

Nucleoside analogues are among the most successful bioactive classes of druglike compounds in pharmaceutical chemistry as they are well-known for their numerous effective bioactivities in humans, especially as antiviral and anticancer agents. Coronavirus disease 2019 (COVID-19) is still untreatable, with its causing virus, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), continuing to wreak havoc on the ground everywhere. This complicated international situation urged all concerned scientists, including medicinal chemists and drug discoverers, to search for a potent anti-COVID-19 drug. Cordycepin (3'-deoxyadenosine) is a known natural adenosine analogue of fungal origin, which could also be synthetically produced. This bioactive phytochemical compound is characterized by several proven strong pharmacological actions that may effectively contribute to the comprehensive treatment of COVID-19, with the antiviral activities being the leading ones. Some new studies predicted the possible inhibitory affinities of cordycepin against the principal SARS-CoV-2 protein targets (e.g., SARS-CoV-2 spike (S) protein, main protease (Mpro) enzyme, and RNA-dependent RNA polymerase (RdRp) enzyme) based on the computational approach. Interestingly, the current research showed, for the first time, that cordycepin is able to potently inhibit the multiplication of the new resistant strains of SARS-CoV-2 with a very minute in vitro anti-SARS-CoV-2 EC50 of about 2 μM, edging over both remdesivir and its active metabolite GS-441524. The ideal pharmacophoric features of the cordycepin molecule render it a typical inhibitor of SARS-CoV-2 replication, with its flexible structure open for most types of derivatization in the future. Briefly, the current findings further support and suggest the repurposing possibility of cordycepin against COVID-19 and greatly encourage us to confidently and rapidly begin its preclinical/clinical evaluations for the comprehensive treatment of COVID-19.

Activation of Sphingomyelinase-Ceramide-Pathway in COVID-19 Purposes Its Inhibition for Therapeutic Strategies

Effective treatment strategies for severe coronavirus disease (COVID-19) remain scarce. Hydrolysis of membrane-embedded, inert sphingomyelin by stress responsive sphingomyelinases is a hallmark of adaptive responses and cellular repair. As demonstrated in experimental and observational clinical studies, the transient and stress-triggered release of a sphingomyelinase, SMPD1, into circulation and subsequent ceramide generation provides a promising target for FDA-approved drugs. Here, we report the activation of sphingomyelinase-ceramide pathway in 23 intensive care patients with severe COVID-19. We observed an increase of circulating activity of sphingomyelinase with subsequent derangement of sphingolipids in serum lipoproteins and from red blood cells (RBC). Consistent with increased ceramide levels derived from the inert membrane constituent sphingomyelin, increased activity of acid sphingomyelinase (ASM) accurately distinguished the patient cohort undergoing intensive care from healthy controls. Positive correlational analyses with biomarkers of severe clinical phenotype support the concept of an essential pathophysiological role of ASM in the course of SARS-CoV-2 infection as well as of a promising role for functional inhibition with anti-inflammatory agents in SARS-CoV-2 infection as also proposed in independent observational studies. We conclude that large-sized multicenter, interventional trials are now needed to evaluate the potential benefit of functional inhibition of this sphingomyelinase in critically ill patients with COVID-19.