Optimizing Hydroxychloroquine Dosing for Patients With COVID-19: An Integrative Modeling Approach for Effective Drug Repurposing

Viral Kinetics Model of SARS-CoV-2 Infection Informs Drug Discovery, Clinical Dose, and Regimen Selection

Quantitative systems pharmacology (QSP) has been an important tool to project safety and efficacy of novel or repurposed therapies for the SARS-CoV-2 virus. Here, we present a QSP modeling framework to predict response to antiviral therapeutics with three mechanisms of action (MoA): cell entry inhibitors, anti-replicatives, and neutralizing biologics. We parameterized three distinct model structures describing virus-host interaction by fitting to published viral kinetics data of untreated COVID-19 patients. The models were used to test theoretical behaviors and map therapeutic design criteria of the different MoAs, identifying the most rapid and robust antiviral activity from neutralizing biologic and anti-replicative MoAs. We found good agreement between model predictions and clinical viral load reduction observed with anti-replicative nirmatrelvir/ritonavir (Paxlovid®) and neutralizing biologics bamlanivimab and casirivimab/imdevimab (REGEN-COV®), building confidence in the modeling framework to inform a dose selection. Finally, the model was applied to predict antiviral response with ensovibep, a novel DARPin therapeutic designed as a neutralizing biologic. We developed a new in silico measure of antiviral activity, area under the curve (AUC) of free spike protein concentration, as a metric with larger dynamic range than viral load reduction. By benchmarking to bamlanivimab predictions, we justified dose levels of 75, 225, and 600 mg ensovibep to be administered intravenously in a Phase 2 clinical investigation. Upon trial completion, we found model predictions to be in good agreement with the observed patient data. These results demonstrate the utility of this modeling framework to guide the development of novel antiviral therapeutics.

Undesirable effects of COVID-19 vaccination on Saudi population: A descriptive study, Winter 2022

Objective

The development of coronavirus disease 2019 (COVID-19) vaccines was a crucial preventative measure toward controlling the pandemic. Several side effects have been reported. This study investigated the long-term side effects reported by the Saudi population. post-COVID-19 vaccination.

Methods

The cross-sectional study involved Saudi participants of both genders, aged ≥16 years, and had received at least one dose of any of the available vaccines in Saudi Arabia. They were asked to fill out an online questionnaire divided into three sections: Demographics, medical history, and side effects that appeared post-COVID-19 vaccines.

Results

The findings indicated that the undesirable effects were reported by 82% of the participants. These side effects involve three categories: The most common, additional or reported, and persistent side effects. The most common side effects were pain at the site of injection (88.16%), bone pain/joint pain (68.7%), and fatigue (68.46%). Menstrual disorders (n = 46), hair loss (n = 34), and memory problems (n = 19) were reported by participants as additional side effects. Among all side effects, fatigue, joint pain, hair loss, and menstrual disorders were the most persistent side effects. Moreover, 190 participants reported that they were diagnosed with diseases soon after receiving the COVID-19 vaccine including COVID-19, thyroid gland disorder, and irritable bowel disease. The quality of life of some of the participants was affected by post-COVID-19 vaccines, as 25.28% had anxiety, 21.22% had depression, and 33.16% had discomfort.

Conclusion

These findings may contribute to understanding the effect of COVID-19 vaccines on the Saudi population's health and public opinion about these vaccines.

In vitro effect of hydroxychloroquine on pluripotent stem cells and their cardiomyocytes derivatives

Introduction: Hydroxychloroquine (HDQ) is an antimalarial drug that has also shown its effectiveness in autoimmune diseases. Despite having side effects such as retinopathy, neuromyopathy and controversial cardiac toxicity, HDQ has been presented and now intensively studied for the treatment and prevention of coronavirus disease 2019 (COVID-19). Recent works revealed both beneficial and toxic effects during HDQ treatment. The cardiotoxic profile of HDQ remains unclear and identifying risk factors is challenging. Methods: Here, we used well-established cell-cultured to study the cytotoxic effect of HDQ, mouse induced pluripotent stem cells (miPSC) and their cardiomyocytes (CMs) derivatives were exposed to different concentrations of HDQ. Cell colony morphology was assessed by microscopy whereas cell viability was measured by flow cytometry and impedance-based methods. The effect of HDQ on beating activity of mouse and human induced pluripotent stem cell-derived CMs (miPSC-CMs and hiPSC-CMs, respectively) and mouse embryonic stem cell-derived CMs (mESC-CMs) were captured by the xCELLigence RTCA and microelectrode array (MEA) systems. Results and discussion: Our results revealed that 20 µM of HDQ promotes proliferation of stem cells used suggesting that if appropriately monitored, HDQ may have a cardioprotective effect and may also represent a possible candidate for tissue repair. In addition, the field potential signals revealed that higher doses of this medication caused bradycardia that could be reversed with a higher concentration of ß-adrenergic agonist, Isoproterenol (Iso). On the contrary, HDQ caused an increase in the beating rate of hiPSC-CMs, which was further helped upon application of Isoproterenol (Iso) suggesting that HDQ and Iso may also work synergistically. These results indicate that HDQ is potentially toxic at high concentrations and can modulate the beating activity of cardiomyocytes. Moreover, HDQ could have a synergistic inotropic effect with isoproterenol on cardiac cells.

The investigation of the complex population-drug-drug interaction between ritonavir-boosted lopinavir and chloroquine or ivermectin using physiologically-based pharmacokinetic modeling

OBJECTIVES

Therapy failure caused by complex population-drug-drug (PDDI) interactions including CYP3A4 can be predicted using mechanistic physiologically-based pharmacokinetic (PBPK) modeling. A synergy between ritonavir-boosted lopinavir (LPVr), ivermectin, and chloroquine was suggested to improve COVID-19 treatment. This work aimed to study the PDDI of the two CYP3A4 substrates (ivermectin and chloroquine) with LPVr in mild-to-moderate COVID-19 adults, geriatrics, and pregnancy populations.

METHODS

The PDDI of LPVr with ivermectin or chloroquine was investigated. Pearson's correlations between plasma, saliva, and lung interstitial fluid (ISF) levels were evaluated. Target site (lung epithelial lining fluid [ELF]) levels of ivermectin and chloroquine were estimated.

RESULTS

Upon LPVr coadministration, while the chloroquine plasma levels were reduced by 30, 40, and 20%, the ivermectin plasma levels were increased by a minimum of 425, 234, and 453% in adults, geriatrics, and pregnancy populations, respectively. The established correlation equations can be useful in therapeutic drug monitoring (TDM) and dosing regimen optimization.

CONCLUSIONS

Neither chloroquine nor ivermectin reached therapeutic ELF levels in the presence of LPVr despite reaching toxic ivermectin plasma levels. PBPK modeling, guided with TDM in saliva, can be advantageous to evaluate the probability of reaching therapeutic ELF levels in the presence of PDDI, especially in home-treated patients.

Systemic exposure to hydroxychloroquine and its relationship with outcome in severely ill COVID-19 patients in New York City

AIM

To investigate the relationship between systemic exposure to hydroxychloroquine (HCQ) and its metabolite desethylhydroxychloroquine (DHCQ) and clinical outcome in severely ill patients treated with a standard oral dose regimen of HCQ during the first wave of COVID-19 in New York City.

METHODS

We correlated retrospective clinical data with drug exposure prospectively assessed from convenience samples using population pharmacokinetics and Bayesian estimation. Systemic exposure was assessed in 215 patients admitted to ICU or COVID-ward for whom an interleukin-6 level was requested and who were still alive 24 hours after the last dose of HCQ. Patients received oral HCQ 600 mg twice daily on day 1 followed by 4 days of 400 mg daily.

RESULTS

Fifty-three precent of the patients were intubated at 5.4 ± 6.4 days after admission and 26.5% died at an average of 32.2 ± 19.1 days. QTc at admission was 448 ± 34 ms. Systemic exposure to HCQ and DHCQ demonstrated substantial variability. Cumulative area under the serum concentration-time curve up to infinity for HCQ was 71.4 ± 19.3 h mg/L and for DHCQ 56.5 ± 28.3 h mg/L. Variability in systemic exposure was not clearly explained by renal function, liver function or inflammatory state. In turn, systemic exposure did not correlate with intubation status, survival or QTc prolongation.

CONCLUSION

This study in severely ill patients was not able to find any relationship between systemic exposure to HCQ and DHCQ and clinical outcome at a routine dose regimen and adds to the growing body of evidence that oral HCQ does not alter the course of disease in COVID-19 patients.

A network biology approach to identify crucial host targets for COVID-19

The ongoing global pandemic of COVID-19, caused by SARS-CoV-2 has killed more than 5.9 million individuals out of ∼43 million confirmed infections. At present, several parts of the world are encountering the 3rd wave. Mass vaccination has been started in several countries but they are less likely to be broadly available for the current pandemic, repurposing of the existing drugs has drawn highest attention for an immediate solution. A recent publication has mapped the physical interactions of SARS-CoV-2 and human proteins by affinity-purification mass spectrometry (AP-MS) and identified 332 high-confidence SARS-CoV-2-human protein-protein interactions (PPIs). Here, we taken a network biology approach and constructed a human protein-protein interaction network (PPIN) with the above SARS-CoV-2 targeted proteins. We utilized a combination of essential network centrality measures and functional properties of the human proteins to identify the critical human targets of SARS-CoV-2. Four human proteins, namely PRKACA, RHOA, CDK5RAP2, and CEP250 have emerged as the best therapeutic targets, of which PRKACA and CEP250 were also found by another group as potential candidates for drug targets in COVID-19. We further found candidate drugs/compounds, such as guanosine triphosphate, remdesivir, adenosine monophosphate, MgATP, and H-89 dihydrochloride that bind the target human proteins. The urgency to prevent the spread of infection and the death of diseased individuals has prompted the search for agents from the pool of approved drugs to repurpose them for COVID-19. Our results indicate that host targeting therapy with the repurposed drugs may be a useful strategy for the treatment of SARS-CoV-2 infection.

Modelling upper respiratory viral load dynamics of SARS-CoV-2

Relationships between viral load, severity of illness, and transmissibility of virus are fundamental to understanding pathogenesis and devising better therapeutic and prevention strategies for COVID-19. Here we present within-host modelling of viral load dynamics observed in the upper respiratory tract (URT), drawing upon 2172 serial measurements from 605 subjects, collected from 17 different studies. We developed a mechanistic model to describe viral load dynamics and host response and contrast this with simpler mixed-effects regression analysis of peak viral load and its subsequent decline. We observed wide variation in URT viral load between individuals, over 5 orders of magnitude, at any given point in time since symptom onset. This variation was not explained by age, sex, or severity of illness, and these variables were not associated with the modelled early or late phases of immune-mediated control of viral load. We explored the application of the mechanistic model to identify measured immune responses associated with the control of the viral load. Neutralising antibodies correlated strongly with modelled immune-mediated control of viral load amongst subjects who produced neutralising antibodies. Our models can be used to identify host and viral factors which control URT viral load dynamics, informing future treatment and transmission blocking interventions.

Chronic Administration of COVID-19 Drugs Fluvoxamine and Lopinavir Shortens Action Potential Duration by Inhibiting the Human Ether-à-go-go-Related Gene and Cav1.2

Background: Old drugs for new indications in the novel coronavirus disease of 2019 (COVID-19) pandemic have raised concerns regarding cardiotoxicity, especially the development of drug-induced QT prolongation. The acute blocking of the cardiac hERG potassium channel is conventionally thought to be the primary mechanism of QT prolongation induced by COVID-19 drugs fluvoxamine (FLV) and lopinavir (LPV). The chronic impact of these medications on the hERG expression has yet to be determined. Methods: To investigate the effect of long-term incubation of FLV and LPV on the hERG channel, we used electrophysiological assays and molecular experiments, such as Western blot, RT-qPCR, and immunofluorescence, in HEK-293 cells stably expressing hERG and human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). Results: Compared to the acute effects, chronic incubation for FLV and LPV generated much lower half-maximal inhibitory concentration (IC50) values, along with a left-shifted activation curve and retarded channel activation. Inconsistent with the reduction in current, we unexpectedly found that the chronic effects of drugs promoted the maturation of hERG proteins, accompanied by the high expression of Hsp70 and low expression of Hsp90. Targeting Hsp70 using siRNA was able to reverse the effects of these drugs on hERG proteins. In addition, FLV and LPV resulted in a significant reduction of APD90 and triggered the early after-depolarizations (EADs), as well as inhibited the protein level of the L-type voltage-operated calcium channel (L-VOCC) in hiPSC-CMs. Conclusion: Chronic incubation with FLV and LPV produced more severe channel-blocking effects and contributed to altered channel gating and shortened action potential duration by inhibiting hERG and Cav1.2.

Drug repurposing for SARS-CoV-2 (COVID-19) treatment

Drug repurposing involves the process of investigating already existing drugs with an aim to use them for different therapeutic purposes than the intended one. This approach is relatively faster, less costly, and reliable in terms of safety as the drug under study is already derisked and known for its other chemistry and pharmacokinetic properties. With these benefits in mind, it is a very reliable way to undertake drug development for emerging diseases such as COVID-19 which demand immediate interventions to slow or completely stop its havoc on mankind. One of the biggest challenges that drug repurposing has is the possibility of the occurrence of new mechanisms of action between the drug ligand and some proteins in the human physiology. Drug repurposing appears to have settled in the meantime in drug development, though more studies in the future will be warranted particularly in regards to resistance.

Repurposing of Drugs for SARS-CoV-2 Using Inverse Docking Fingerprints

Severe acute respiratory syndrome coronavirus 2 or SARS-CoV-2 is a virus that belongs to the Coronaviridae family. This group of viruses commonly causes colds but possesses a tremendous pathogenic potential. In humans, an outbreak of SARS caused by the SARS-CoV virus was first reported in 2003, followed by 2012 when the Middle East respiratory syndrome coronavirus (MERS-CoV) led to an outbreak of Middle East respiratory syndrome (MERS). Moreover, COVID-19 represents a serious socioeconomic and global health problem that has already claimed more than four million lives. To date, there are only a handful of therapeutic options to combat this disease, and only a single direct-acting antiviral, the conditionally approved remdesivir. Since there is an urgent need for active drugs against SARS-CoV-2, the strategy of drug repurposing represents one of the fastest ways to achieve this goal. An in silico drug repurposing study using two methods was conducted. A structure-based virtual screening of the FDA-approved drug database on SARS-CoV-2 main protease was performed, and the 11 highest-scoring compounds with known 3CLpro activity were identified while the methodology was used to report further 11 potential and completely novel 3CLpro inhibitors. Then, inverse molecular docking was performed on the entire viral protein database as well as on the Coronaviridae family protein subset to examine the hit compounds in detail. Instead of target fishing, inverse docking fingerprints were generated for each hit compound as well as for the five most frequently reported and direct-acting repurposed drugs that served as controls. In this way, the target-hitting space was examined and compared and we can support the further biological evaluation of all 11 newly reported hits on SARS-CoV-2 3CLpro as well as recommend further in-depth studies on antihelminthic class member compounds. The authors acknowledge the general usefulness of this approach for a full-fledged inverse docking fingerprint screening in the future.

Impact of SARS-CoV-2 on pregnancy outcomes (Review)

The impact of the pandemic outbreak associated with coronavirus 2019 disease (COVID-19) on pregnant women is of interest to obstetricians and gynecologists due to the vulnerability of this target group. In pregnant women and their infants, an exceptional clinical management is warranted. Current epidemiological findings provide information regarding the effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on pregnant patients and potential adverse perinatal outcomes. Overall, these findings are a strong indication that an increased antenatal surveillance for pregnant patients infected with COVID-19 is warranted. The aim of the present narrative review was to summarize the data obtained to date regarding the health of women during pregnancy, as well as that of the fetus associated with the risk of severe infection due to COVID-19. The present review aimed to provide further insight into the effects of this pandemic on pregnancy, also providing the experience of the authors on this matter as an example.

A review of mathematical model-based scenario analysis and interventions for COVID-19

Mathematical model-based analysis has proven its potential as a critical tool in the battle against COVID-19 by enabling better understanding of the disease transmission dynamics, deeper analysis of the cost-effectiveness of various scenarios, and more accurate forecast of the trends with and without interventions. However, due to the outpouring of information and disparity between reported mathematical models, there exists a need for a more concise and unified discussion pertaining to the mathematical modeling of COVID-19 to overcome related skepticism. Towards this goal, this paper presents a review of mathematical model-based scenario analysis and interventions for COVID-19 with the main objectives of (1) including a brief overview of the existing reviews on mathematical models, (2) providing an integrated framework to unify models, (3) investigating various mitigation strategies and model parameters that reflect the effect of interventions, (4) discussing different mathematical models used to conduct scenario-based analysis, and (5) surveying active control methods used to combat COVID-19.

Model-Informed Repurposing of Medicines for SARS-CoV-2: Extrapolation of Antiviral Activity and Dose Rationale for Paediatric Patients

Repurposing of remdesivir and other drugs with potential antiviral activity has been the basis of numerous clinical trials aimed at SARS-CoV-2 infection in adults. However, expeditiously designed trials without careful consideration of dose rationale have often resulted in treatment failure and toxicity in the target patient population, which includes not only adults but also children. Here we show how paediatric regimens can be identified using pharmacokinetic-pharmacodynamic (PKPD) principles to establish the target exposure and evaluate the implications of dose selection for early and late intervention. Using in vitro data describing the antiviral activity and published pharmacokinetic data for the agents of interest, we apply a model-based approach to assess the exposure range required for adequate viral clearance and eradication. Pharmacokinetic parameter estimates were subsequently used with clinical trial simulations to characterise the probability target attainment (PTA) associated with enhanced antiviral activity in the lungs. Our analysis shows that neither remdesivir, nor anti-malarial drugs can achieve the desirable target exposure range based on a mg/kg dosing regimen, due to a limited safety margin and high concentrations needed to ensure the required PTA. To date, there has been limited focus on suitable interventions for children affected by COVID-19. Most clinical trials have defined doses selection criteria empirically, without thorough evaluation of the PTA. The current results illustrate how model-based approaches can be used for the integration of clinical and nonclinical data, providing a robust framework for assessing the probability of pharmacological success and consequently the dose rationale for antiviral drugs for the treatment of SARS-CoV-2 infection in children.

'de Novo' repurposing of Daflon as anti-intestinal parasitic drug in experimental giardiasis

BACKGROUND

There is a necessity to develop or discover an alternative drug to combat the drug resistance by Giardia duodenalis and minimize the multiple doses and frequency of the conventional drug administration. Progressive repositioning or 'repurposing' of drugs has become widespread due to economic circumstances and medical emergency needs. Daflon 500 mg (DFL) is a natural product used safely as a nutrient supplement and an antidiabetic drug in many European countries and the US.

OBJECTIVE

This study aimed at investigating the efficiency of DFL, in vivo, in a murine model as a safe alternative or co-drug for giardiasis.

MATERIALS AND METHODS

Swiss Albino mice (n = 32) were inoculated with 1X10⁴Giardia cysts and assigned to four groups: One group was the infected non-treated control mice and three experimental groups that were treated differently, either with Metronidazole (MTZ), DFL, or combined therapy of DFL/MTZ. Also, eight normal mice served as a control group. All mice were sacrificed 13 days post-infection for the parasitic, histopathological, and oxidative stress analysis.

RESULTS

MTZ, DFL, and the combined therapy significantly reduced the number of trophozoites and cysts compared to their counterparts of the infected mice. The histopathological analysis of the small intestines of the mice treated with the combined therapy retained typical intestinal architecture and normal levels of malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione.

CONCLUSION

This study indicated promising actions of Daflon 500 as an anti-giardial drug, and the results demonstrated its potential effect in improving the intestinal epithelial tissue and disturbing the Giardia stages when it was taken collectively with Metronidazole.

Ayurveda botanicals in COVID-19 management: An in silico multi-target approach

The Coronavirus disease (COVID-19) caused by the virus SARS-CoV-2 has become a global pandemic in a very short time span. Currently, there is no specific treatment or vaccine to counter this highly contagious disease. There is an urgent need to find a specific cure for the disease and global efforts are directed at developing SARS-CoV-2 specific antivirals and immunomodulators. Ayurvedic Rasayana therapy has been traditionally used in India for its immunomodulatory and adaptogenic effects, and more recently has been included as therapeutic adjuvant for several maladies. Amongst several others, Withania somnifera (Ashwagandha), Tinospora cordifolia (Guduchi) and Asparagus racemosus (Shatavari) play an important role in Rasayana therapy. The objective of this study was to explore the immunomodulatory and anti SARS-CoV2 potential of phytoconstituents from Ashwagandha, Guduchi and Shatavari using network pharmacology and docking. The plant extracts were prepared as per ayurvedic procedures and a total of 31 phytoconstituents were identified using UHPLC-PDA and mass spectrometry studies. To assess the immunomodulatory potential of these phytoconstituents an in-silico network pharmacology model was constructed. The model predicts that the phytoconstituents possess the potential to modulate several targets in immune pathways potentially providing a protective role. To explore if these phytoconstituents also possess antiviral activity, docking was performed with the Spike protein, Main Protease and RNA dependent RNA polymerase of the virus. Interestingly, several phytoconstituents are predicted to possess good affinity for the three targets, suggesting their application for the termination of viral life cycle. Further, predictive tools indicate that there would not be adverse herb-drug pharmacokinetic-pharmacodynamic interactions with concomitantly administered drug therapy. We thus make a compelling case to evaluate the potential of these Rasayana botanicals as therapeutic adjuvants in the management of COVID-19 following rigorous experimental validation.

Anti-malarial Drugs are Not Created Equal for SARS-CoV-2 Treatment: A Computational Analysis Evidence

BACKGROUND

The evolution of the pandemic has burdened the national healthcare systems worldwide and at present, there is no preferred antiviral treatment for COVID-19. Recently, the SARS-Cov-2 protease structure was released that may be exploited in in-silico studies in order to conduct molecular docking analysis.

METHODS

In particular, we compared the binding of twoantimalarial drugs, already in use, (i.e. chloroquine and hydroxychloroquine), which showed some potential clinical effects on COVID-19 patients, using ritonavir, lopinavir and darunavir as positive control tree antiviral recognized compounds.

RESULTS

Our results showed that hydroxychloroquine but not chloroquine exhibited a significant binding activity to the main protease similar to that possessed by protease inhibitors tested for other viral infections.

CONCLUSION

Our data suggest that hydroxychloroquine may exert additional direct antiviral activity compared to chloroquine. In the absence of clinical studies comparing the efficacy of these two compounds, hydroxychloroquine may offer additional effects and may be considered as the first choice.

Brief review on repurposed drugs and vaccines for possible treatment of COVID-19

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the causative agent of the pandemic coronavirus disease 2019 (Covid-19) has claimed more than a million lives. Various in silico, in vitro, and in vivo studies are being conducted to understand the effect of SARS-CoV-2 on the cellular metabolism of humans and the various drugs and drug-targets that may be used. In this review, we discuss protein-protein interactions (PPIs) between viral and human proteins as well as viral targets like proteases. We try to understand the molecular mechanism of various repurposed antiviral drugs against SARS-CoV-2, their combination therapies, drug dosage regimens, and their adverse effects along with possible alternatives like non-toxic antiviral phytochemicals. Ultimately, randomized controlled trials are needed to identify which of these compounds has the required balance of efficacy and safety. We also focus on the recent advancements in diagnostic methods and vaccine candidates developed around the world to fight against Covid-19.

Mortality, viral clearance, and other clinical outcomes of hydroxychloroquine in COVID-19 patients: A systematic review and meta-analysis of randomized controlled trials

Many meta-analyses have been published about the efficacy of hydroxychloroquine (HCQ) in coronavirus disease 2019 (COVID-19). Most of them included observational studies, and few have assessed HCQ as a prophylaxis or evaluated its safety profile. We searched multiple databases and preprint servers for randomized controlled trials (RCTs) that assessed HCQ for the treatment or prevention of COVID-19. We summarized the effect of HCQ on mortality, viral clearance, and other clinical outcomes. Out of 768 papers screened, 21 RCTs with a total of 14,138 patients were included. A total of 9 inpatient and 3 outpatient RCTs assessed mortality in 8596 patients with a pooled risk difference of 0.01 (95% confidence interval [CI] 0.00-0.03, I2  = 1%, p = 0.07). Six studies assessed viral clearance at 7 days with a pooled risk ratio (RR) of 1.11 (95% CI 0.86-1.42, I2  = 61%, p = 0.44) and 5 studies at 14 days with a pooled RR of 0.96 (95% CI 0.89-1.04, I2  = 0%, p = 0.34). Several trials showed no significant effect of HCQ on other clinical outcomes and. Five prevention RCTs with 5012 patients found no effect of HCQ on the risk of acquiring COVID-19. Thirteen trials showed that HCQ was associated with increased risk of adverse events. We observed, with high level of certainty of evidence, that HCQ is not effective in reducing mortality in patients with COVID-19. Lower certainty evidence also suggests that HCQ neither improves viral clearance and other clinical outcomes, nor prevents COVID-19 infection in patients with high-risk exposure. HCQ is associated with an increased rate of adverse events.

Chloroquine and Hydroxychloroquine for the Prevention and Treatment of COVID-19: A Fiction, Hope or Hype? An Updated Review

In December 2019, the novel coronavirus disease pandemic (COVID-19) that began in China had infected so far more than 109,217,366 million individuals worldwide and accounted for more than 2,413,912 fatalities. With the dawn of this novel coronavirus (SARS-CoV-2), there was a requirement to select potential therapies that might effectively kill the virus, accelerate the recovery, or decrease the case fatality rate. Besides the currently available antiviral medications for human immunodeficiency virus (HIV) and hepatitis C virus (HCV), the chloroquine/hydroxychloroquine (CQ/HCQ) regimen with or without azithromycin has been repurposed in China and was recommended by the National Health Commission, China in mid-February 2020. By this time, the selection of this regimen was based on its efficacy against the previous SARS-CoV-1 virus and its potential to inhibit viral replication of the SARS-CoV-2 in vitro. There was a shortage of robust clinical proof about the effectiveness of this regimen against the novel SARS-CoV-2. Therefore, extensive research effort has been made by several researchers worldwide to investigate whether this regimen is safe and effective for the management of COVID-19. In this review, we provided a comprehensive overview of the CQ/HCQ regimen, summarizing data from in vitro studies and clinical trials for the protection against or the treatment of SARS-CoV-2. Despite the initial promising results from the in vitro studies and the widespread use of CQ/HCQ in clinical settings during the 1st wave of COVID-19, current data from well-designed randomized controlled trials showed no evidence of benefit from CQ/HCQ supplementation for the treatment or prophylaxis against SARS-CoV-2 infection. Particularly, the two largest randomized controlled trials to date (RECOVERY and WHO SOLIDARITY trials), both confirmed that CQ/HCQ regimen does not provide any clinical benefit for COVID-19 patients. Therefore, we do not recommend the use of this regimen in COVID-19 patients outside the context of clinical trials.

Exploring insights of hydroxychloroquine, a controversial drug in Covid-19: An update

The review summarizes chloroquine (CQ) and its safer derivative hydroxychloroquine (HCQ) and its utility in Covid-19. Recently this well-established drug made its way back to the headlines during the SARS-CoV-2 pandemic. This led to an upsurge in the scientific arena with multiple research and review articles along with expert opinions and commentaries. The HCQ has received mixed judgements so far about its efficacy to be used in Covid-19 patients in a limited trial conducted all across the Globe. The purpose of our article is to put forth the history, pharmacodynamics, and pharmacokinetics, along with the existing studies favouring and disapproving the role of HCQ in the treatment of Covid-19. We grouped HCQ use at three stages, this includes HCQ for i. prophylactic use by asymptomatic health workers or peoples at higher risk; ii. patients having mild symptoms; iii. patients with extreme symptoms. The review critically discusses the underlying plausible reasons and mechanisms exploring HCQ in prophylactic management or treatment of SARS-CoV-2. Furthermore, we have critically analysed the reported pharmacokinetic parameters and compiled the proponent, opponent, or neutral opinions on the use of HCQ in Covid-19. Authors discretion is to conduct more studies considering the optimal dosing regimen and pharmacokinetics assessment.

Coronavirus Disease 2019 (COVID-19) Pharmacologic Treatments for Children: Research Priorities and Approach to Pediatric Studies

Clinical trials of pharmacologic treatments of coronavirus disease 2019 (COVID-19) are being rapidly designed and implemented in adults. Children are often not considered during development of novel treatments for infectious diseases until very late. Although children appear to have a lower risk compared with adults of severe COVID-19 disease, a substantial number of children globally will benefit from pharmacologic treatments. It will be reasonable to extrapolate efficacy of most treatments from adult trials to children. Pediatric trials should focus on characterizing a treatment's pharmacokinetics, optimal dose, and safety across the age spectrum. These trials should use an adaptive design to efficiently add or remove arms in what will be a rapidly evolving treatment landscape, and should involve a large number of sites across the globe in a collaborative effort to facilitate efficient implementation. All stakeholders must commit to equitable access to any effective, safe treatment for children everywhere.

Combination of Hydroxychloroquine Plus Azithromycin As Potential Treatment for COVID-19 Patients: Safety Profile, Drug Interactions, and Management of Toxicity

The coronavirus disease 2019 (COVID-19), caused by infection with severe acute respiratory syndrome coronavirus 2, has recently emerged worldwide. In this context, there is an urgent need to identify safe and effective therapeutic strategies for treatment of such highly contagious disease. We recently reported promising results of combining hydroxychloroquine and azithromycin as an early treatment option. Although ongoing clinical trials are challenging the efficacy of this combination, many clinicians claim the authorization to or have already begun to use it to treat COVID-19 patients worldwide. The aim of this article is to share pharmacology considerations contributing to the rationale of this combination, and to provide safety information to prevent toxicity and drug-drug interactions, based on available evidence.

Chloroquine and hydroxychloroquine for COVID-19: Perspectives on their failure in repurposing

WHAT IS KNOWN AND OBJECTIVE

Non-clinical studies suggest that chloroquine (CQ) and hydroxychloroquine (HCQ) have antiviral activities. Early clinical reports of successful HCQ-associated reduction in viral load from small studies in COVID-19 patients spurred a large number of national and international clinical trials to test their therapeutic potential. The objective of this review is to summarize the current evidence on the safety and efficacy of these two agents and to provide a perspective on why their repurposing has hitherto failed.

METHODS

Published studies and rapidly emerging data were reviewed to gather evidence on safety and efficacy of CQ and HCQ in patients with COVID-19 infection or as prophylaxis. The focus is on clinically relevant efficacy endpoints and their adverse effects on QT interval.

RESULTS AND DISCUSSION

At the doses used, the two agents, given alone or with azithromycin (AZM), are not effective in COVID-19 infection. The choice of (typically subtherapeutic) dosing regimens, influenced partly by "QT-phobia," varied widely and seems anecdotal without any pharmacologically reliable supporting clinical evidence. A substantial proportion of patients receiving CQ/HCQ/AZM regimen developed QTc interval prolongation, many with absolute QTc interval exceeding the potential proarrhythmic threshold, but very few developed proarrhythmia.

WHAT IS NEW AND CONCLUSION

The strategy to repurpose CQ/HCQ to combat COVID-19 infection is overshadowed by concerns about their QT liability, resulting in choice of potentially subtherapeutic doses. Although the risk of QT-related proarrhythmia is real, it is low and manageable by careful monitoring. Recent discontinuation of HCQ from at least four large studies effectively marks the end of efforts at repurposing of CQ or HCQ for COVID-19 infection. This episode leaves behind important questions on dose selection and risk/benefit balance in repurposing drugs generally.

Optimization of hydroxychloroquine dosing scheme based on COVID-19 patients' characteristics: a review of the literature and simulations

During the recent COVID-19 outbreak hydroxychloroquine (HCQ) has been proposed as a safe and effective therapeutic option. However, a wide variety of dosing schemes has been applied in the clinical practice and tested in clinical studies. An extended literature survey was performed investigating the pharmacokinetics, the efficacy and safety of HCQ in COVID-19 treatment. Population pharmacokinetic models were retrieved from the literature and after evaluation and assessment one was selected in order to perform simulations. The most commonly applied dosing schemes were explored for patients with different weights and different levels of HCQ clearance impairment. Model-based simulations of HCQ concentrations revealed that high initial doses followed by low and sparse doses may offer significant benefits to patients by decreasing the viral load without reaching levels considered to produce adverse effects. For instance, the dosing scheme proposed for a 70 kg adult with moderate COVID-19 symptoms would be 600 mg upon diagnosis, 400 mg after 12 h, 300 mg after 24 h, 200 mg after 36 h, followed by 200 mg BID for 4 d, followed by 200 mg OD for 5 d. Based on the results from simulations performed and the currently published knowledge regarding HCQ in COVID-19 treatment, this study provides evidence that a high loading dose followed by sparse doses could offer significant benefits to the patients.

Systematic review and meta-analysis of the effectiveness and safety of hydroxychloroquine in treating COVID-19 patients

BACKGROUND

Since COVID-19 outbreak, hydroxychloroquine (HCQ) has been tested for effective therapies, and the relevant researches have shown controversial results.

METHODS

Systematic review and meta-analysis were conducted after a thorough search of relevant studies from databases. Trials that have evaluated HCQ for COVID-19 treatment were recruited for statistical analysis with fixed- and random-effect models.

RESULTS

Nine trials involving 4112 patients were included in present meta-analysis. It was seen that HCQ-azithromycin (HCQ-AZI) combination regimen increased the mortality rate in COVID-19 (odds ratio [OR], 2.34; 95% confidence interval [CI], 1.63-3.36) patients; however, it also showed benefits associated with the viral clearance in patients (OR, 27.18; 95% CI, 1.29-574.32). HCQ-alone when used as a therapy in COVID-19 did not reveal significant changes in mortality rate, clinical progression, viral clearance, and cardiac QT prolongation. Subsequent subgroup analysis showed that HCQ treatment could decrease mortality rate and progression to severe illness in severely infected COVID-19 patients (OR, 0.27; 95% CI, 0.13-0.58). A lower risk of mortality rate was also noted in the stratified group of >14 days follow-up period (OR, 0.27; 95% CI, 0.13-0.58) compared to ≤14 days follow-up period group that conversely showed an increased mortality rate (OR, 2.09; 95% CI, 1.41-3.10).

CONCLUSION

Our results indicated that HCQ-AZI combination treatment increased mortality rate in patients with COVID-19, but it also showed benefits associated with viral clearance in patients. HCQ-alone used for treatment has revealed benefits in decreasing the mortality rate among severely infected COVID-19 group and showed potential to be used for COVID-19 treatment in long-term follow-up period group. Accordingly, more rigorous, large-scale, and long follow-up period studies in patients with COVID-19 are needed.

Pharmacokinetics and pharmacodynamics of hydroxychloroquine in hospitalized patients with COVID-19

BACKGROUND

Hydroxychloroquine (HCQ) dosage required to reach circulating levels that inhibit SARS-Cov-2 are extrapolated from pharmacokinetic data in non-COVID-19 patients.

METHODS

We performed a population-pharmacokinetic analysis from 104 consecutive COVID-19 hospitalized patients (31 in intensive care units, 73 in medical wards, n=149 samples). Plasma HCQ concentration were measured using high performance liquid chromatography with fluorometric detection. Modelling used Monolix-2019R2.

RESULTS

HCQ doses ranged from 200 to 800mg/day administered for 1 to 11days and median HCQ plasma concentration was 151ng/mL. Among the tested covariates, only bodyweight influenced elimination oral clearance (CL) and apparent volume of distribution (Vd). CL/F (F for unknown bioavailability) and Vd/F (relative standard-error, %) estimates were 45.9L/h (21.2) and 6690L (16.1). The derived elimination half-life (t1/2) was 102h. These parameters in COVID-19 differed from those reported in patients with lupus, where CL/F, Vd/F and t1/2 are reported to be 68L/h, 2440 L and 19.5h, respectively. Within 72h of HCQ initiation, only 16/104 (15.4%) COVID-19 patients had HCQ plasma levels above the in vitro half maximal effective concentration of HCQ against SARS-CoV-2 (240ng/mL). HCQ did not influence inflammation status (assessed by C-reactive protein) or SARS-CoV-2 viral clearance (assessed by real-time reverse transcription-PCR nasopharyngeal swabs).

CONCLUSION

The interindividual variability of HCQ pharmacokinetic parameters in severe COVID-19 patients was important and differed from that previously reported in non-COVID-19 patients. Loading doses of 1600mg HCQ followed by 600mg daily doses are needed to reach concentrations relevant to SARS-CoV-2 inhibition within 72hours in≥60% (95% confidence interval: 49.5-69.0%) of COVID-19 patients.

Connecting Hydroxychloroquine In Vitro Antiviral Activity to In Vivo Concentration for Prediction of Antiviral Effect: A Critical Step in Treating Patients With Coronavirus Disease 2019

Translation of in vitro antiviral activity to the in vivo setting is crucial to identify potentially effective dosing regimens of hydroxychloroquine. In vitro 50%/90% maximal effective concentration values for hydroxychloroquine should be compared to the in vivo free extracellular tissue concentration, which is similar to the free plasma hydroxychloroquine concentration.

Hydroxychloroquine and SARS-CoV-2 (COVID-19): An Old Problem and New Considerations in Ophthalmology

The antimalarial hydroxychloroquine (HCQ) has been suggested as a potential drug for treatment and prevention against severe acute respiratory syndrome–coronavirus 2 (SARS–CoV-2). Currently, there is insufficient scientific evidence available on HCQ retinal toxicity associated with the current treatment regimen and dosing for COVID-19 patients. In the sight of the current public health crisis, our recommendations aim to reduce the probability of unfavorable HCQ treatment outcomes and emphasize the importance of monitoring and early detection for HCQ retinopathy by simple means and the need for correlating clinical observations with multimodal imaging. We, therefore, recommend the use of Threshold Amsler grid (TAG) as a screening tool for high risk COVID-19 patients as well as treated patients with visual symptoms. Clinical decisions should be made on an individual basis, taking into consideration any pre-existing liver and kidney disease as well as macular pathology.

Ayurveda botanicals in COVID-19 management: An in silico multi-target approach

The Coronavirus disease (COVID-19) caused by the virus SARS-CoV-2 has become a global pandemic in a very short time span. Currently, there is no specific treatment or vaccine to counter this highly contagious disease. There is an urgent need to find a specific cure for the disease and global efforts are directed at developing SARS-CoV-2 specific antivirals and immunomodulators. Ayurvedic Rasayana therapy has been traditionally used in India for its immunomodulatory and adaptogenic effects, and more recently has been included as therapeutic adjuvant for several maladies. Amongst several others, Withania somnifera (Ashwagandha), Tinospora cordifolia (Guduchi) and Asparagus racemosus (Shatavari) play an important role in Rasayana therapy. The objective of this study was to explore the immunomodulatory and anti SARS-CoV2 potential of phytoconstituents from Ashwagandha, Guduchi and Shatavari using network pharmacology and docking. The plant extracts were prepared as per ayurvedic procedures and a total of 31 phytoconstituents were identified using UHPLC-PDA and mass spectrometry studies. To assess the immunomodulatory potential of these phytoconstituents an in-silico network pharmacology model was constructed. The model predicts that the phytoconstituents possess the potential to modulate several targets in immune pathways potentially providing a protective role. To explore if these phytoconstituents also possess antiviral activity, docking was performed with the Spike protein, Main Protease and RNA dependent RNA polymerase of the virus. Interestingly, several phytoconstituents are predicted to possess good affinity for the three targets, suggesting their application for the termination of viral life cycle. Further, predictive tools indicate that there would not be adverse herb-drug pharmacokinetic-pharmacodynamic interactions with concomitantly administered drug therapy. We thus make a compelling case to evaluate the potential of these Rasayana botanicals as therapeutic adjuvants in the management of COVID-19 following rigorous experimental validation.

Insights on the Evidence of Cardiotoxicity of Hydroxychloroquine Prior and During COVID-19 Epidemic

The recent empirical use of hydroxychloroquine (HCQ) in coronavirus disease 2019 (COVID-19) revived the interest in its cardiac toxicity, increasingly sidelined over time. We aimed to assess and compare the profile of cardiac adverse drug reactions (CADRs) associated with HCQ before and during COVID-19. We performed a retrospective comparative observational study using the French Pharmacovigilance network database between 1985 and May 2020 to assess all postmarketing CADRs associated with HCQ notified before COVID-19 in its approved indications for lupus and rheumatoid arthritis (preCOV), and those concerning its empirical use in COVID-19 (COV). Eighty-five CADR in preCOV were compared with 141 CADRs in COV. The most common CADR of preCOV were cardiomyopathies (42.4%) and conduction disorders (28.2%), both statistically more frequent than in COV (P < 0.001). COV notifications significantly highlighted repolarization and ventricular rhythm disorders (78.0%, P < 0.001) as well as sinus bradycardias (14.9%, P = 0.01) as compared with preCOV. Estimated incidence of CADR was significantly higher among patients exposed to off-label use of HCQ in COVID-19 (2.9%) than before COVID-19 in its approved indications (0.01%, P < 0.001). The use of HCQ in COVID-19 sheds a new light on the spectrum of its cardiac toxicity. This fosters the value of a closer monitoring of all patients treated with HCQ, regardless of its indication, and the importance of an update of its summary of product characteristics.

A systematic review and meta-analysis on chloroquine and hydroxychloroquine as monotherapy or combined with azithromycin in COVID-19 treatment

Many recent studies have investigated the role of either Chloroquine (CQ) or Hydroxychloroquine (HCQ) alone or in combination with azithromycin (AZM) in the management of the emerging coronavirus. This systematic review and meta-analysis of either published or preprint observational studies or randomized control trials (RCT) aimed to assess mortality rate, duration of hospital stay, need for mechanical ventilation (MV), virologic cure rate (VQR), time to a negative viral polymerase chain reaction (PCR), radiological progression, experiencing drug side effects, and clinical worsening. A search of the online database through June 2020 was performed and examined the reference lists of pertinent articles for in-vivo studies only. Pooled relative risks (RRs), standard mean differences of 95% confidence intervals (CIs) were calculated with the random-effects model. Mortality was not different between the standard care (SC) and HCQ groups (RR = 0.99, 95% CI 0.61-1.59, I2 = 82%), meta-regression analysis proved that mortality was significantly different across the studies from different countries. However, mortality among the HCQ + AZM was significantly higher than among the SC (RR = 1.8, 95% CI 1.19-2.27, I2 = 70%). The duration of hospital stay in days was shorter in the SC in comparison with the HCQ group (standard mean difference = 0.57, 95% CI 0.20-0.94, I2 = 92%), or the HCQ + AZM (standard mean difference = 0.77, 95% CI 0.46-1.08, I2 = 81). Overall VQR, and that at days 4, 10, and 14 among patients exposed to HCQ did not differ significantly from the SC [(RR = 0.92, 95% CI 0.69-1.23, I2 = 67%), (RR = 1.11, 95% CI 0.26-4.69, I2 = 85%), (RR = 1.21, 95% CI 0.70-2.01, I2 = 95%), and (RR = 0.98, 95% CI 0.76-1.27, I2 = 85% )] respectively. Exposure to HCQ + AZM did not improve the VQR as well (RR = 3.23, 95% CI 0.70-14.97, I2 = 58%). The need for MV was not significantly different between the SC and HCQ (RR = 1.5, 95% CI 0.78-2.89, I2 = 81%), or HCQ + AZM (RR = 1.27, 95% CI 0.7-2.13, I2 = 88%). Side effects were more reported in the HCQ group than in the SC (RR = 3.14, 95% CI 1.58-6.24, I2 = 0). Radiological improvement and clinical worsening were not statistically different between HCQ and SC [(RR = 1.11, 95% CI 0.74-1.65, I2 = 45%) and (RR = 1.28, 95% CI 0.33-4.99), I2 = 54%] respectively. Despite the scarcity of published data of good quality, the effectiveness and safety of either HCQ alone or in combination with AZM in treating COVID-19 cannot be assured. Future high-quality RCTs need to be carried out.PROSPERO registration: CRD42020192084.

Hydroxychloroquine as a Chemoprophylactic Agent for COVID-19: A Clinico-Pharmacological Review

Hydroxychloroquine has gained much attention as one of the candidate drugs that can be repurposed as a prophylactic agent against SARS-CoV-2, the agent responsible for the COVID-19 pandemic. Due to high transmissibility and presence of asymptomatic carriers and presymptomatic transmission, there is need for a chemoprophylactic agent to protect the high-risk population. In this review, we dissect the currently available evidence on hydroxychloroquine prophylaxis from a clinical and pharmacological point of view. In vitro studies on Vero cells show that hydroxychloroquine effectively inhibits SARS-CoV-2 by affecting viral entry and viral transport via endolysosomes. However, this efficacy has failed to replicate in in vivo animal models as well as in most clinical observational studies and clinical trials assessing pre-exposure prophylaxis and postexposure prophylaxis in healthcare workers. An analysis of the pharmacology of HCQ in COVID-19 reveals certain possible reasons for this failure-a pharmacokinetic failure due to failure to achieve adequate drug concentration at the target site and attenuation of its inhibitory effect due to the presence of TMPRSS2 in airway epithelial cells. Currently, many clinical trials on HCQ prophylaxis in HCW are ongoing; these factors should be taken into account. Using higher doses of HCQ for prophylaxis is likely to be associated with increased safety concerns; thus, it may be worthwhile to focus on other possible interventions.

Hydroxychloroquine as Prophylaxis for COVID-19: A Review

The impact of the COVID-19 pandemic worldwide has led to a desperate search for effective drugs and vaccines. There are still no approved agents for disease prophylaxis. We thus decided to use a drug repositioning strategy to perform a state-of-the-art review of a promising but controversial drug, hydroxychloroquine (HCQ), in an effort to provide an objective, scientific and methodologically correct overview of its potential prophylactic role. The advantage of using known drugs is that their toxicity profile is well known and there are fewer commercial interests (e.g., expired patents), thus allowing the scientific community to be freer of constraints. The main disadvantage is that the economic resources are almost always insufficient to promote large multinational clinical trials. In the present study, we reviewed the literature and available data on the prophylactic use of HCQ. We also took an in-depth look at all the published clinical data on the drug and examined ongoing clinical trials (CTs) from the most important CT repositories to identify a supporting rationale for HCQ prophylactic use. Our search revealed a substantial amount of preclinical data but a lack of clinical data, highlighting the need to further assess the translational impact of in vitro data in a clinical setting. We identified 77 CTs using a multiplicity of HCQ schedules, which clearly indicates that we are still far from reaching a standard of care. The majority of the CTs (92%) are randomized and 53% are being conducted in a phase 3 or 2/3 setting. The comparator is placebo or control in 55 (77%) of the randomized studies. Forty-eight (62%) CTs expect to enroll up to 1,000 subjects and 50 (71%) plan to recruit healthcare workers (HCW). With regard to drug schedules, 45 (58.5%) CTs have planned a loading dose, while 18 (23.4%) have not; the loading dose is 800 mg in 19 trials (42.2%), 400 mg in 19 (42.2%), 600 mg in 4 (8.9%) and 1,200 mg in 1 (2.2%). Forty trials include at least one daily schedule, while 19 have at least one weekly schedule. Forty-one (53.2%) will have a treatment duration of more than 30 days. Awaiting further developments that can only derive from the results of these prospective randomized CTs, the take-home message of our review is that a correct methodological approach is the key to understanding whether prophylactic HCQ can really represent an effective strategy in preventing COVID-19.

Can endolysosomal deacidification and inhibition of autophagy prevent severe COVID-19?

The possibility is examined that immunomodulatory pharmacotherapy may be clinically useful in managing the pandemic coronavirus disease 2019 (COVID-19), known to result from infection by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a positive-sense single-stranded RNA virus. The dominant route of cell entry of the coronavirus is via phagocytosis, with ensconcement in endosomes thereafter proceeding via the endosomal pathway, involving transfer from early (EEs) to late endosomes (LEs) and ultimately into lysosomes via endolysosomal fusion. EE to LE transportation is a rate-limiting step for coronaviruses. Hence inhibition or dysregulation of endosomal trafficking could potentially inhibit SARS-CoV-2 replication. Furthermore, the acidic luminal pH of the endolysosomal system is critical for the activity of numerous pH-sensitive hydrolytic enzymes. Golgi sub-compartments and Golgi-derived secretory vesicles also depend on being mildly acidic for optimal function and structure. Activation of endosomal toll-like receptors by viral RNA can upregulate inflammatory mediators and contribute to a systemic inflammatory cytokine storm, associated with a worsened clinical outcome in COVID-19. Such endosomal toll-like receptors could be inhibited by the use of pharmacological agents which increase endosomal pH, thereby reducing the activity of acid-dependent endosomal proteases required for their activity and/or assembly, leading to suppression of antigen-presenting cell activity, decreased autoantibody secretion, decreased nuclear factor-kappa B activity and decreased pro-inflammatory cytokine production. It is also noteworthy that SARS-CoV-2 inhibits autophagy, predisposing infected cells to apoptosis. It is therefore also suggested that further pharmacological inhibition of autophagy might encourage the apoptotic clearance of SARS-CoV-2-infected cells.

[Adverse reactions of drugs specifically used for treatment of SARS-CoV-2 infection]

Currently, there is no treatment approved for COVID-19. Numerous drugs are being used in an empirical manner according to experience and availability. Studies demonstrating their efficacy and safety are still to be published. Thus, it is of vital importance for healthcare workers to be well informed and updated regarding possible immunological and non-immunological adverse effects regarding such treatments. In this narrative revision, the rationale use of these treatments in the SARS-CoV-2 infection is emphasized as well as their most frequently described adverse drug reactions. Drugs that are being essayed to counteract both clinical phases that are thought to take place in the severe stage of this disease are included; an initial phase where a viral infection prevails and a second phase where an inflammatory response takes over. Adverse reactions registered in the Pharmacovigilance Program of our hospital before the onset of this pandemic have also been included.

Population Pharmacokinetics of Hydroxychloroquine in COVID-19 Patients: Implications for Dose Optimization

Background and Objective

In the absence of characterization on pharmacokinetics and reference concentrations for hydroxychloroquine in COVID-19 patients, the dose and treatment duration for hydrochloroquine are currently empirical, mainly based on in vitro data, and may vary across national guidelines and clinical study protocols. The aim of this paper is to describe the pharmacokinetics of hydroxychloroquine in COVID-19 patients, considered to be a key step toward its dosing optimization.

Methods

We have developed a population pharmacokinetic model for hydroxychloroquine in COVID-19 patients using prospectively collected pharmacokinetic data from patients either enrolled in a clinical trial or treated with hydroxychloroquine as part of standard of care in two tertiary Belgian hospitals.

Results

The final population pharmacokinetic model was a one-compartment model with first-order absorption and elimination. The estimated parameter values were 9.3/h, 860.8 L, and 15.7 L/h for the absorption rate constant, the central compartment volume, and the clearance, respectively. The bioavailability factor was fixed to 0.74 based on previously published models. Model validations by bootstraps, prediction corrected visual predictive checks, and normalized prediction distribution errors gave satisfactory results. Simulations were performed to compare the exposure obtained with alternative dosing regimens.

Conclusion

The developed models provide useful insight for the dosing optimization of hydroxychloroquine in COVID-19 patients. The present results should be used in conjunction with exposure-efficacy and exposure-safety data to inform optimal dosing of hydroxychloroquine in COVID-19.

Electronic supplementary material

The online version of this article (10.1007/s13318-020-00648-y) contains supplementary material, which is available to authorized users.

Pharmacokinetic Basis of the Hydroxychloroquine Response in COVID-19: Implications for Therapy and Prevention

BACKGROUND AND OBJECTIVES

Chloroquine/hydroxychloroquine has recently been the subject of intense debate regarding its potential antiviral activity against SARS-Cov-2, the etiologic agent of COVID-19. Some report possible curative effects; others do not. Therefore, the objective of this study was to simulate possible scenarios of response to hydroxychloroquine in COVID-19 patients using mathematical modeling.

METHODS

To shed some light on this controversial topic, we simulated hydroxychloroquine-based interventions on virus/host cell dynamics using a basic system of previously published differential equations. Mathematical modeling was implemented using Python programming language v 3.7.

RESULTS

According to mathematical modeling, hydroxychloroquine may have an impact on the amplitude of the viral load peak and viral clearance if the drug is administered early enough (i.e., when the virus is still confined within the pharyngeal cavity). The effects of chloroquine/hydroxychloroquine may be fully explained only when also considering the capacity of this drug to increase the death rate of SARS-CoV-2-infected cells, in this case by enhancing the cell-mediated immune response.

CONCLUSIONS

These considerations may not only be applied to chloroquine/hydroxychloroquine but may have more general implications for development of anti-COVID-19 combination therapies and prevention strategies through an increased death rate of the infected cells.

Natural and Synthetic Drugs as Potential Treatment for Coronavirus Disease 2019 (COVID-2019)

Coronavirus disease 2019 (COVID-19) has become a global pandemic in a short period, where a tragically large number of human lives being lost. It is an infectious pandemic that recently infected more than two hundred countries in the world. Many potential treatments have been introduced, which are considered potent antiviral drugs and commonly reported as herbal or traditional and medicinal treatments. A variety of bioactive metabolites extracts from natural herbal have been reported for coronaviruses with some effective results. Food and Drug Administration (FDA) has approved numerous drugs to be introduced against COVID-19, which commercially available as antiviral drugs and vaccines. In this study, a comprehensive review is discussed on the potential antiviral remedies based on natural and synthetic drugs. This review highlighted the potential remedies of COVID-19 which successfully applied to patients with high cytopathic inhibition potency for cell-to-cell spread and replication of coronavirus.

Hydroxychloroquine in COVID-19 Patients: Pros and Cons

The pandemic of COVID-19, caused by SARS-CoV-2, has recently overwhelmed medical centers and paralyzed economies. The unparalleled public distress caused by this pandemic mandated an urgent quest for an effective approach to manage or treat this disease. Due to their well-established anti-infectious and anti-inflammatory properties, quinine derivatives have been sought as potential therapies for COVID-19. Indeed, these molecules were originally employed in the treatment and prophylaxis of malaria, and later in the management of various autoimmune rheumatic and dermatologic diseases. Initially, some promising results for the use of hydroxychloroquine (HCQ) in treating COVID-19 patients were reported by a few in vitro and in vivo studies. However, current evidence is not yet sufficiently solid to warrant its use as a therapy for this disease. Additionally, the therapeutic effects of HCQ are not without many side effects, which range from mild gastrointestinal effects to life-threatening cardiovascular and neurological effects. In this review, we explore the controversy associated with the repurposing of HCQ to manage or treat COVID-19, and we discuss the cellular and molecular mechanisms of action of HCQ.

Recent Clinical and Preclinical Studies of Hydroxychloroquine on RNA Viruses and Chronic Diseases: A Systematic Review

The rapid spread of the new Coronavirus Disease 2019 (COVID-19) has actually become the newest challenge for the healthcare system since, to date, there is not an effective treatment. Among all drugs tested, Hydroxychloroquine (HCQ) has attracted significant attention. This systematic review aims to analyze preclinical and clinical studies on HCQ potential use in viral infection and chronic diseases. A systematic search of Scopus and PubMed databases was performed to identify clinical and preclinical studies on this argument; 2463 papers were identified and 133 studies were included. Regarding HCQ activity against COVID-19, it was noticed that despite the first data were promising, the latest outcomes highlighted the ineffectiveness of HCQ in the treatment of viral infection. Several trials have seen that HCQ administration did not improve severe illness and did not prevent the infection outbreak after virus exposure. By contrast, HCQ arises as a first-line treatment in managing autoimmune diseases such as rheumatoid arthritis, lupus erythematosus, and Sjögren syndrome. It also improves glucose and lipid homeostasis and reveals significant antibacterial activity.

Identify potent SARS-CoV-2 main protease inhibitors via accelerated free energy perturbation-based virtual screening of existing drugs

The COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global crisis. There is no therapeutic treatment specific for COVID-19. It is highly desirable to identify potential antiviral agents against SARS-CoV-2 from existing drugs available for other diseases and thus repurpose them for treatment of COVID-19. In general, a drug repurposing effort for treatment of a new disease, such as COVID-19, usually starts from a virtual screening of existing drugs, followed by experimental validation, but the actual hit rate is generally rather low with traditional computational methods. Here we report a virtual screening approach with accelerated free energy perturbation-based absolute binding free energy (FEP-ABFE) predictions and its use in identifying drugs targeting SARS-CoV-2 main protease (Mpro). The accurate FEP-ABFE predictions were based on the use of a restraint energy distribution (RED) function, making the practical FEP-ABFE-based virtual screening of the existing drug library possible. As a result, out of 25 drugs predicted, 15 were confirmed as potent inhibitors of SARS-CoV-2 Mpro The most potent one is dipyridamole (inhibitory constant Ki = 0.04 µM) which has shown promising therapeutic effects in subsequently conducted clinical studies for treatment of patients with COVID-19. Additionally, hydroxychloroquine (Ki = 0.36 µM) and chloroquine (Ki = 0.56 µM) were also found to potently inhibit SARS-CoV-2 Mpro We anticipate that the FEP-ABFE prediction-based virtual screening approach will be useful in many other drug repurposing or discovery efforts.

The association of treatment with hydroxychloroquine and hospital mortality in COVID-19 patients

This study investigates the association between the treatment with hydroxychloroquine and mortality in patients admitted with COVID-19. Routinely recorded, clinical data, up to the 24th of April 2020, from the 2075 patients with COVID-19, admitted in 17 hospitals in Spain between the 1st of March and the 20th of April 2020 were used. The following variables were extracted for this study: age, gender, temperature, and saturation of oxygen on admission, treatment with hydroxychloroquine, azithromycin, heparin, steroids, tocilizumab, a combination of lopinavir with ritonavir, and oseltamivir, together with data on mortality. Multivariable logistic regression models were used to investigate the associations. At the time of collecting the data, 301 patients had died, 1449 had been discharged home from the hospitals, 240 were still admitted, and 85 had been transferred to hospitals not included in the study. Median follow-up time was 8 (IQR 5-12) days. Hydroxychloroquine had been used in 1857 patients. Hydroxychloroquine was associated with lower mortality when the model was adjusted for age and gender, with OR (95% CI): 0.44 (0.29-0.67). This association remained significant when saturation of oxygen < 90% and temperature > 37 °C were added to de model with OR 0.45 (0.30-0.68) p < 0.001, and also when all the other drugs, and time of admission, were included as covariates. The association between hydroxychloroquine and lower mortality observed in this study can be acknowledged by clinicians in hospitals and in the community. Randomized-controlled trials to assess the causal effects of hydroxychloroquine in different therapeutic regimes are required.

It is time to drop hydroxychloroquine from our COVID-19 armamentarium

Chloroquine (CQ) and hydroxychloroquine (HCQ) were among the first drugs repurposed for the treatment of SARS-CoV-2 infection. A few in vitro studies confirmed that both drugs exhibited dose dependent anti-SARS-CoV-2 activities. These observations and the encouraging results from early poorly conducted observational studies created a major hype about the therapeutic potential of these drugs in the treatment of COVID-19 disease. This was further catalyzed by media and political influences leading to a widespread use of these agents. Subsequent randomized trials revealed lack of efficacy of these agents in improving the outcomes of COVID-19 or in preventing infection in post-exposure prophylaxis studies. Nevertheless, many ongoing trials continue to actively recruit tens of thousands of patients to receive HCQ worldwide. In this perspective, we address the possible mechanisms behind the lack of efficacy and the increased risk of cardiac toxicity of HCQ in COVID-19 disease. For the lack of efficacy, we discuss the fundamental differences of treatment initiation between in vitro and in vivo studies, the pitfalls of the pharmacological calculations of effective blood drug concentrations and related dosing regimens, and the possible negative effect of HCQ on the antiviral type-I interferon response. Although it has been repeatedly claimed that HCQ has a longstanding safety track record for many decades in use, we present counterarguments for this contention due to disease-drug and drug-drug interactions. We discuss the molecular mechanisms and the cumulative epidemiological evidence of HCQ cardiac toxicity.

Favipiravir at high doses has potent antiviral activity in SARS-CoV-2-infected hamsters, whereas hydroxychloroquine lacks activity

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rapidly spread around the globe after its emergence in Wuhan in December 2019. With no specific therapeutic and prophylactic options available, the virus has infected millions of people of which more than half a million succumbed to the viral disease, COVID-19. The urgent need for an effective treatment together with a lack of small animal infection models has led to clinical trials using repurposed drugs without preclinical evidence of their in vivo efficacy. We established an infection model in Syrian hamsters to evaluate the efficacy of small molecules on both infection and transmission. Treatment of SARS-CoV-2-infected hamsters with a low dose of favipiravir or hydroxychloroquine with(out) azithromycin resulted in, respectively, a mild or no reduction in virus levels. However, high doses of favipiravir significantly reduced infectious virus titers in the lungs and markedly improved lung histopathology. Moreover, a high dose of favipiravir decreased virus transmission by direct contact, whereas hydroxychloroquine failed as prophylaxis. Pharmacokinetic modeling of hydroxychloroquine suggested that the total lung exposure to the drug did not cause the failure. Our data on hydroxychloroquine (together with previous reports in macaques and ferrets) thus provide no scientific basis for the use of this drug in COVID-19 patients. In contrast, the results with favipiravir demonstrate that an antiviral drug at nontoxic doses exhibits a marked protective effect against SARS-CoV-2 in a small animal model. Clinical studies are required to assess whether a similar antiviral effect is achievable in humans without toxic effects.

Preparation and physicochemical stability of 50 mg/mL hydroxychloroquine oral suspension in SyrSpendⓇ SF PH4 (dry)

In the context of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, hydroxychloroquine has been proposed as a potential agent to treat patients with COVID-19 (coronavirus disease 2019) caused by SARS-CoV-2 infection. Older adults are more susceptible to COVID-19 and some patients may require admission to the intensive care unit, where oral drug administration of solid forms may be compromised in many COVID-19 patients. However, a liquid formulation of hydroxychloroquine is not commercially available. This study describes how to prepare a 50 mg/mL hydroxychloroquine oral suspension using hydroxychloroquine sulfate powder and SyrSpend^Ⓡ SF PH4 (dry) suspending vehicle. Moreover, a fully validated stability-indicating method has been developed to demonstrate the physicochemical stability of the compounded hydroxychloroquine oral suspension over 60 days under refrigeration (5 ± 3 °C). Finally, use of the proposed oral suspension provides a reliable solution to perform safe and accurate administration of hydroxychloroquine to patients with SARS-CoV-2 infection.

Applying computer simulations in battling with COVID-19, using pre-analyzed molecular and chemical data to face the pandemic

Coronavirus disease 2019 (COVID-19) has made many concerns for healthcare services especially, in finding useful therapeutic(s). Despite the scientists’ struggle to find and/or creating possible drugs, so far there is no treatment with high efficiency for the disease. During the pandemic, researchers have performed some molecular analyses to find potential therapeutics out of both the natural and synthetic available medicines. Computer simulations and related data have shown a significant role in drug discovery and development before. In this field, antiviral drugs, phytochemicals, anti-inflammatory agents, etc. were essential groups of compounds tested against COVID-19, using molecular modeling, molecular dynamics (MD), and docking tools. The results indicate promising effects of such compounds to be used in further experimental and clinical trials; Chloroquine, Chloroquine-OH, and Umifenovir as viral entry inhibitors, Remdesivir, Ribavirin, Lopinavir, Ritonavir, and Darunavir as viral replication inhibitors, and Sirolimus are the examples, which were tested clinically on patients after comprehensive assessments of the available data on molecular simulation. This review summarizes the outcomes of various computer simulations data in the battle against COVID-19.

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More knowledge of SARS-CoV-2 genomic and structural characterization is necessary.

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Computer simulation can find possible natural or synthetic compounds for COVID-19.

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Molecular docking compares binding affinity of drugs to COVID-19 related targets.

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Network drug repurposing determines COVID-19 associated target genes and pathways.