COVID-19: Famotidine, Histamine, Mast Cells, and Mechanisms

Effectiveness of famotidine on the risk of poor prognosis in patients with COVID-19: A nationwide cohort study in Korea

Objective

Famotidine has been proposed as a promising candidate for the treatment of coronavirus disease 2019 (COVID-19). However, there is limited research on the association of famotidine with the poor prognosis of COVID-19.

Methods

The Korean nationwide cohort included 6,556 patients who tested positive on RT-PCR for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The poor COVID-19-related outcomes were defined on the basis of having encountered the composite outcome of high oxygen therapy, intensive care unit admission, administration of mechanical ventilation, or death. In addition, we performed exposure-driven propensity score matching for no H₂-blocker use versus current famotidine use, and other H₂-blocker use versus current famotidine use.

Results

4,785 (73.0%) patients did not use a H₂-blocker, 393 (6.0%) patients were currently used famotidine, and 1,292 (19.7%) patients currently used H₂-blocker other than famotidine. In multivariable analysis after matching (no H₂-blocker use versus current famotidine use), there was no significant association between current famotidine use and composite outcomes (adjusted odd ratios [aOR]: 1.30, 95% confidence interval [CI]: 0.55-3.06). On the other hand, another matched cohort (other H₂-blocker use versus current famotidine use), demonstrated a positive association between current famotidine use and composite outcomes (aOR: 3.56, 95% CI: 1.03-12.28).

Conclusions

Our study results did not support the potential of famotidine as a therapeutic agent for COVID-19. A rather unexpected result could be observed in the comparisons between current famotidine use and other H₂-blocker use; it was observed that current famotidine use increased the risk of poor COVID-19 related outcomes. Further studies are needed to clearly prove the causal relationship with several H2-blockers, including famotidine.

Efficacy of Oral Famotidine in Patients Hospitalized With Severe Acute Respiratory Syndrome Coronavirus 2

Introduction

The clinical benefit of famotidine has been observed in the management of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, its use in the management of SARS-CoV-2 is intriguing and not well established yet. In this study, we aimed to determine the role of famotidine as adjuvant therapy in improving the outcome of patients hospitalized with coronavirus disease-2019 (COVID-19).

Methods

This two-arm open-label randomized interventional study was conducted in the COVID-19 unit of a tertiary care hospital in Pakistan from December 2020 to September 2021. Patients between the ages of 18 to 65 years, hospitalized with COVID-19 infection, were enrolled in the study. Participants were randomized into two groups. The intervention group received 40 mg oral famotidine daily in addition to the standard care and the control group received standard care as per national guidelines for the treatment of COVID-19 in Pakistan.

Results

Patients admitted with COVID-19 who received famotidine took comparatively fewer days to become symptom-free (8.5 ± 1.7 vs. 9.4 ± 1.9 days, p-value: <0.001) and spent fewer days in hospital (8.6 ± 1.6 vs. 10.3 ± 2.2 days; p-value: <0.0001). However, the overall difference in the need for mechanical ventilation and mortality between the interventional arm and placebo was not significant.

Conclusion

In this study, adding famotidine to standard treatment of COVID-19 was associated with faster clinical recovery and shorter stay in the hospital. However, there was no difference in the need for mechanical ventilation, need for intensive care unit, and overall mortality. Further large-scale studies are needed to understand the role of famotidine in COVID-19 and its mechanism of action in patients with COVID-19.

Therapeutic Options for Coronavirus Disease 2019 (COVID-19): Where Are We Now?

PURPOSE OF REVIEW

Rapidly evolving treatment paradigms of coronavirus disease 2019 (COVID-19) introduce challenges for clinicians to keep up with the pace of published literature and to critically appraise the voluminous data produced. This review summarizes the clinical evidence from key studies examining the place of therapy of recommended drugs and management strategies for COVID-19.

RECENT FINDINGS

The global magnitude and duration of the pandemic have resulted in a flurry of interventional treatment trials evaluating both novel and repurposed drugs targeting various aspects of the viral life cycle. Additionally, clinical observations have documented various stages or phases of COVID-19 and underscored the importance of timing for the efficacy of studied therapies. Since the start of the COVID-19 pandemic, many observational, retrospective, and randomized controlled studies have been conducted to guide management of COVID-19 using drug therapies and other management strategies. Large, randomized, or adaptive platform trials have proven the most informative to guide recommended treatments to-date. Antimicrobial stewardship programs can play a pivotal role in ensuring appropriate use of COVID-19 therapies based on evolving clinical data and limiting unnecessary antibiotics given low rates of co-infection.

SUMMARY

Given the rapidly evolving medical literature and treatment paradigms, it is recommended to reference continuously updated, curated guidelines from national and international sources. While the drugs and management strategies mentioned in this review represent the current state of recommendations, many therapies are still under investigation to further define optimal COVID-19 treatment.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s11908-021-00769-8.

The impact of asthma on in-hospital outcomes of COVID-19 patients

OBJECTIVE

The impact of asthma as a possible risk factor for adverse clinical outcomes in patients diagnosed with COVID-19 remains controversial. The purpose of this study was to examine the impact of asthma on adverse clinical outcomes in a COVID-19 hospitalized cohort.

METHODS

Retrospective, propensity-matched observational study of consecutive COVID-19-positive patients between February 24, 2020, and November 3, 2020 at a single health care system.

RESULTS

In the initial population of 1925 patients, 4.4% presented with asthma. Propensity score matching reduced the total sample to n = 1045: 88 (8.4%) with asthma and n = 957 without asthma. A total of 164 (15.7%) patients died during the hospitalization, including 7 (8.0%) in the asthma group and 157 (16.4%), p = .037, in the non-asthmatic cohort. There was no difference between these groups in need for mechanical ventilation, length of stay on a ventilator, or hospital length of stay.Logistic regression analysis demonstrated that asthma was an independent predictor of lower mortality, while older age, BMI > 30 kg/m², heart failure, chronic kidney disease, and admission National Early Warning Score (NEWS) were significantly associated with an increased risk of in-hospital death. There were no significant differences between asthmatic and non-asthmatic cohorts with respect to need for mechanical ventilation, length of mechanical ventilation, serum markers of severe COVID-19 disease, or overall length of hospital stay.

CONCLUSION

We conclude that asthma in hospitalized COVID-19 patients is associated with a lower risk of mortality and no increase in disease severity in hospitalized COVID-19 patients.

COVID-19: Immunology, Immunopathogenesis and Potential Therapies

The Coronavirus Disease-2019 (COVID-19) imposed public health emergency and affected millions of people around the globe. As of January 2021, 100 million confirmed cases of COVID-19 along with more than 2 million deaths were reported worldwide. SARS-CoV-2 infection causes excessive production of pro-inflammatory cytokines thereby leading to the development of "Cytokine Storm Syndrome." This condition results in uncontrollable inflammation that further imposes multiple-organ-failure eventually leading to death. SARS-CoV-2 induces unrestrained innate immune response and impairs adaptive immune responses thereby causing tissue damage. Thus, understanding the foremost features and evolution of innate and adaptive immunity to SARS-CoV-2 is crucial in anticipating COVID-19 outcomes and in developing effective strategies to control the viral spread. In the present review, we exhaustively discuss the sequential key immunological events that occur during SARS-CoV-2 infection and are involved in the immunopathogenesis of COVID-19. In addition to this, we also highlight various therapeutic options already in use such as immunosuppressive drugs, plasma therapy and intravenous immunoglobulins along with various novel potent therapeutic options that should be considered in managing COVID-19 infection such as traditional medicines and probiotics.

Experimental Pharmacotherapy for COVID-19: The Latest Advances

The coronavirus infectious disease-2019 (COVID-19) has overwhelmed like a shock wave in a completely unprepared world. Despite coronavirus infections were involved in previous epidemic outbreaks, no antiviral agent was developed for specific treatment. As a consequence, since the beginning of this pandemic, both repositioned and experimental drugs were used to treat the infected patients without evidence of clinical efficacy. Just based on experience coming from the use of antiviral agents to treat other viruses (eg, lopinavir/ritonavir, remdesivir) and supposed antiviral or immunomodulatory activities of drugs with no approved antiviral indications (eg hydroxychloroquine, tocilizumab), clinicians have faced the ongoing pandemic. Currently, after about 9 months from the COVID-19 spread, there is still no antiviral agent capable of ensuring the cure of this syndrome. Clinical trials are beginning to confirm the benefits of some drugs, while for other compounds, efficacy and safety have not yet been confirmed. Randomized clinical trials (RCT) have denied or downsized the beneficial effects attributed to certain molecules, such as aminoquinolines, largely used in clinical practice at the beginning of COVID-19 spread. Conversely, at the same time, they have provided evidence for unexpected effectiveness of other agents that have been underutilized, such as steroids, which were not used in SARS treatment because of the threatened effect on viral replication. Evidence deriving from pathologic studies have demonstrated that the prothrombotic effects of SARS-CoV-2 can be prevented by heparin prophylaxis, underlining the need for personalized treatment for patients with severe disease. The main aim of this review is to synthesize the available information and evidence on both repositioned and experimental drugs for the treatment of COVID-19, focusing on the need to exercise caution on the use of unproven medical therapies.

Does Famotidine Reduce the Risk of Progression to Severe Disease, Death, and Intubation for COVID-19 Patients? A Systemic Review and Meta-Analysis

BACKGROUND

Famotidine was reported to potentially provide benefits to Coronavirus Disease 2019 (COVID-19) patients. However, it remains controversial whether it is effective in treating COVID-19.

AIMS

This study aimed to explore whether famotidine use is associated with reduced risk of the severity, death, and intubation for COVID-19 patients.

METHODS

This study was registered on International Prospective Register of Systematic Reviews (PROSPERO) (ID: CRD42020213536). A comprehensive search was performed to identify relevant studies up to October 2020. I-squared statistic and Q-test were utilized to assess the heterogeneity. Pooled risk ratios (RR) and 95% confidence intervals (CI) were calculated through the random effects or fixed effects model according to the heterogeneity. Subgroup analyses, sensitivity analysis, and publication bias assessment were also conducted.

RESULTS

Five studies including 36,635 subjects were included. We found that famotidine use was associated with a statistically non-significant reduced risk of progression to severe disease, death, and intubation for Coronavirus Disease 2019 (COVID-19) patients (pooled RR was 0.82, 95% CI = 0.52-1.30, P = 0.40).

CONCLUSION

Famotidine has no significant protective effect in reducing the risk of developing serious illness, death, and intubation for COVID-19 patients. More original studies are needed to further clarify whether it is associated with reduced risk of the severity, death, and intubation for COVID-19 patients.

Overview of Targets and Potential Drugs of SARS-CoV-2 According to the Viral Replication

Since the novel coronavirus pandemic, people around the world have been touched in varying degrees, and this pandemic has raised a major global health concern. As there is no effective drug or vaccine, it is urgent to find therapeutic drugs that can serve to deal with the current epidemic situation in all countries and regions. We searched drugs and response measures for SARS-CoV-2 in the PubMed database, and then updated the potential targets and therapeutic drugs from the perspective of the viral replication cycle. The drug research studies of the viral replication cycle are predominantly focused on the process of the virus entering cells, proteases, and RdRp. The inhibitors of the virus entry to cells and RdRp, such as Arbidol, remdesivir, favipiravir, EIDD-2081, and ribavirin, are in clinical trials, while most of the protease inhibitors are mainly calculated by molecular docking technology, which needs in vivo and in vitro experiments to prove the effect for SARS-CoV-2. This review summarizes the drugs targeting the viral replication process and provides a basis and directions for future drug development and reuse on the protein level of COVID-19.

COVID-19 and Gastrointestinal Disease: Implications for the Gastroenterologist

BACKGROUND

COVID-19 was initially considered a respiratory disease but the SARS-CoV-2 virus can lead to serious systemic consequences affecting major organs including the digestive system.

SUMMARY

This review brings new clinically important information for the gastroenterologist. This includes: the mechanisms of tissue damage seen with the SARS-CoV-2 virus; the consequences of immunosuppression in patients with inflammatory bowel disease (IBD) and chronic liver disease with the additional risks of decompensation in patients with cirrhosis; the impact of COVID-19 on gastrointestinal emergencies, on gastrointestinal endoscopy, diagnosis and treatments. These highlight the need to understand the clinical pharmacology, toxicology and therapeutic implications of drugs commonly used by gastroenterologists and their links with COVID-19. Key Messages: Any part of the digestive system may be affected by the SARS-CoV-2 virus, and those with pre-existing disease are at greatest risk of adverse outcomes. The risk for drug-drug interactions is considerable in patients seriously ill with COVID-19 who often require mechanical ventilation and life support. Some repurposed drugs used against SARS-CoV-2 can cause or aggravate some of the COVID-19-related gastrointestinal symptoms and can also induce liver injury. Ongoing clinical studies will hopefully identify effective drugs with a more favourable risk-benefit ratio than many initially tried treatments.

Impact of Famotidine Use on Clinical Outcomes of Hospitalized Patients With COVID-19

INTRODUCTION

To compare outcomes in patients hospitalized with coronavirus (COVID-19) receiving famotidine therapy with those not receiving famotidine.

METHODS

Retrospective, propensity-matched observational study of consecutive COVID-19-positive patients between February 24, 2020, and May 13, 2020.

RESULTS

Of 878 patients in the analysis, 83 (9.5%) received famotidine. In comparison to patients not treated with famotidine, patients treated with famotidine were younger (63.5 ± 15.0 vs 67.5 ± 15.8 years, P = 0.021), but did not differ with respect to baseline demographics or preexisting comorbidities. Use of famotidine was associated with a decreased risk of in-hospital mortality (odds ratio 0.37, 95% confidence interval 0.16-0.86, P = 0.021) and combined death or intubation (odds ratio 0.47, 95% confidence interval 0.23-0.96, P = 0.040). Propensity score matching to adjust for age difference between groups did not alter the effect on either outcome. In addition, patients receiving famotidine displayed lower levels of serum markers for severe disease including lower median peak C-reactive protein levels (9.4 vs 12.7 mg/dL, P = 0.002), lower median procalcitonin levels (0.16 vs 0.30 ng/mL, P = 0.004), and a nonsignificant trend to lower median mean ferritin levels (797.5 vs 964.0 ng/mL, P = 0.076). Logistic regression analysis demonstrated that famotidine was an independent predictor of both lower mortality and combined death/intubation, whereas older age, body mass index >30 kg/m, chronic kidney disease, National Early Warning Score, and higher neutrophil-lymphocyte ratio were all predictors of both adverse outcomes.

DISCUSSION

Famotidine use in hospitalized patients with COVID-19 is associated with a lower risk of mortality, lower risk of combined outcome of mortality and intubation, and lower levels of serum markers for severe disease in hospitalized patients with COVID-19.(Equation is included in full-text article.).

No Time to Waste: Real-World Repurposing of Generic Drugs as a Multifaceted Strategy Against COVID-19

Real-world drug repurposing-the immediate "off-label" prescribing of drugs to address urgent clinical needs-is an indispensable strategy gaining rapid traction in the current COVID-19 crisis. Although off-label prescribing (ie, for a nonapproved indication) is legal in most countries, it tends to shift the burden of liability and cost to physicians and patients, respectively. Nevertheless, in urgent public health crises, it is often the only realistic source of a meaningful potential solution. To be considered for real-world repurposing, drug candidates should ideally have a track record of safety, affordability, and wide accessibility. Although thousands of such drugs are already available, the absence of a central repository of off-label uses presents a barrier to the immediate identification and selection of the safest, potentially useful interventions. Using the current COVID-19 pandemic as an example, we provide a glimpse at the extensive literature that supports the rationale behind six generic drugs, in four classes, all of which are affordable, supported by decades of safety data, and pleiotropically target the underlying pathophysiology that makes COVID-19 so dangerous. Having previously fast-tracked this paper to publication in summary form, we now expand on why cimetidine/famotidine (histamine type-2 receptor antagonists), dipyridamole (antiplatelet agent), fenofibrate/bezafibrate (cholesterol/triglyceride-lowering agents), and sildenafil (phosphodiesterase-5 inhibitor) are worth considering for patients with COVID-19 based on their antiviral, anti-inflammatory, renoprotective, cardioprotective, and anticoagulation properties. These examples also reveal the unlimited opportunity to future-proof public health by proactively mining, synthesizing, and cataloging the off-label treatment opportunities of thousands of safe, well-established, and affordable generic drugs.