The effectiveness of gabapentin and gabapentin/montelukast combination compared with dextromethorphan in the improvement of COVID-19- related cough: A randomized, controlled clinical trial.

INTRODUCTION: Cough is one of the most common presenting symptoms of COVID-19, which can persist for weeks or months. OBJECTIVE: The goal of this study was to evaluate the effectiveness of gabapentin (GBT) alone and in combination with montelukast (MTL) for improving cough. METHODS: In this open-label randomized controlled clinical trial, eligible cases were patients hospitalized with moderate to severe COVID-19 who had cough with a Breathlessness, Cough, and Sputum Scale (BCSS) score of at least 2 based on its cough subscale. The participants were randomly assigned to three groups including two experimental groups and one control group. The first and second experimental groups received GBT and GBT/MTL, respectively, whereas the control group received dextromethorphan (DXM). Treatment duration was 5 days in all groups. Before and after the interventions, the severity of cough was evaluated using BCSS scale and Visual Analog Scale (VAS). RESULTS: A total of 180 patients were included; GPT, GPT/MTL, and DXM consisted of 76, 51, and 53 patients, respectively. There was no significant difference between the three groups in terms of age, gender, and comorbidities (P > 0.05). Regarding BCSS and VAS scores, there was significant reduction from the baseline values in all groups (P < 0.0001), with the change rate being significantly higher in DXM group. The amount of reduction of BCSS in the GPT/MTL group was significantly more than the GPT group, whereas there was no significant difference between the two groups regarding VAS score. Although the duration of hospitalization differed between the groups with the GPT/MTL group having the shortest duration, the difference was statistically significant only between the GPT and GPT/MTL groups (P < 0.0001). CONCLUSION: GPT, both alone and in combination with MTL, improves cough frequency and severity in hospitalized patients with COVID-19, with the combination being more efficacious. This regimen may be useful in patients who cannot tolerate opioids.

Systematic optimization of host-directed therapeutic targets and preclinical validation of repositioned antiviral drugs.

Inhibition of host protein functions using established drugs produces a promising antiviral effect with excellent safety profiles, decreased incidence of resistant variants and favorable balance of costs and risks. Genomic methods have produced a large number of robust host factors, providing candidates for identification of antiviral drug targets. However, there is a lack of global perspectives and systematic prioritization of known virus-targeted host proteins (VTHPs) and drug targets. There is also a need for host-directed repositioned antivirals. Here, we integrated 6140 VTHPs and grouped viral infection modes from a new perspective of enriched pathways of VTHPs. Clarifying the superiority of nonessential membrane and hub VTHPs as potential ideal targets for repositioned antivirals, we proposed 543 candidate VTHPs. We then presented a large-scale drug-virus network (DVN) based on matching these VTHPs and drug targets. We predicted possible indications for 703 approved drugs against 35 viruses and explored their potential as broad-spectrum antivirals. In vitro and in vivo tests validated the efficacy of bosutinib, maraviroc and dextromethorphan against human herpesvirus 1 (HHV-1), hepatitis B virus (HBV) and influenza A virus (IAV). Their drug synergy with clinically used antivirals was evaluated and confirmed. The results proved that low-dose dextromethorphan is better than high-dose in both single and combined treatments. This study provides a comprehensive landscape and optimization strategy for druggable VTHPs, constructing an innovative and potent pipeline to discover novel antiviral host proteins and repositioned drugs, which may facilitate their delivery to clinical application in translational medicine to combat fatal and spreading viral infections.

In silico screening predicts common cold drug Dextromethorphan along with Prednisolone and Dexamethasone can be effective against novel Coronavirus disease (COVID-19).

The ongoing outbreak of Coronavirus disease 2019 (COVID-19) is a matter of great concern. Although the mortality rate caused by this virus is less than that of SARS and MERS, it is showing higher efficacy in terms of human-to-human transmission. Several strategies have been taken by scientists and researchers worldwide to combat this virus. Numerous phytochemicals and synthesized chemicals are under incessant inspection to obtain a potent anti-covid drug. Since, till now no precise therapy is available for covid patients, researchers are trying to categorize all possible anti-covid substances. Repurposing of drugs and combined drug therapy are becoming popular in treating such viral diseases. In this study, we are proposing the repurposing of three chemicals-Dextromethorphan, Prednisolone and Dexamethasone as anti-covid agents. We have used the tertiary structure of Coronavirus main protease (Mpro) with PDB ID 6LU7 as the target protein in this analysis. Molecular docking and dynamics study further revealed their synergistic effect against the COVID-19 protease protein.Communicated by Ramaswamy H. Sarma.

Insights into the biased activity of dextromethorphan and haloperidol towards SARS-CoV-2 NSP6: in silico binding mechanistic analysis.

The outbreak of novel coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) virus continually led to infect a large population worldwide. SARS-CoV-2 utilizes its NSP6 and Orf9c proteins to interact with sigma receptors that are implicated in lipid remodeling and ER stress response, to infect cells. The drugs targeting the sigma receptors, sigma-1 and sigma-2, have emerged as effective candidates to reduce viral infectivity, and some of them are in clinical trials against COVID-19. The antipsychotic drug, haloperidol, exerts remarkable antiviral activity, but, at the same time, the sigma-1 benzomorphan agonist, dextromethorphan, showed pro-viral activity. To explore the potential mechanisms of biased binding and activity of the two drugs, haloperidol and dextromethorphan towards NSP6, we herein utilized molecular docking-based molecular dynamics simulation studies. Our extensive analysis of the protein-drug interactions, structural and conformational dynamics, residual frustrations, and molecular switches of NSP6-drug complexes indicates that dextromethorphan binding leads to structural destabilization and increase in conformational dynamics and energetic frustrations. On the other hand, the strong binding of haloperidol leads to minimal structural and dynamical perturbations to NSP6. Thus, the structural insights of stronger binding affinity and favorable molecular interactions of haloperidol towards viral NSP6 suggests that haloperidol can be potentially explored as a candidate drug against COVID-19. KEY MESSAGES: •Inhibitors of sigma receptors are considered as potent drugs against COVID-19. •Antipsychotic drug, haloperidol, binds strongly to NSP6 and induces the minimal changes in structure and dynamics of NSP6. •Dextromethorphan, agonist of sigma receptors, binding leads to overall destabilization of NSP6. •These two drugs bind with NSP6 differently and also induce differences in the structural and conformational changes that explain their different mechanisms of action. •Haloperidol can be explored as a candidate drug against COVID-19.