High-dose cimetidine reduces proinflammatory reaction after cardiac surgery with cardiopulmonary bypass

Correlation between Medications Used during COVID Infection and Post-conditions after the Acute Phase of Infection: A Cross-sectional Study

Background:

During the COVID-19 pandemic, off-label medication prescribing and utilizing herbal products and multiple vitamins in the treatment, prevention, and symptom management of COVID-19 was an urgently needed practice to halt the SARS-CoV-2 infection crisis and progression.

Objectives:

This study aimed to determine the correlation between medications used during the pandemic and SARS-CoV-2 infection post-recovery symptoms.

Methods:

A cross-sectional questionnaire-based study was conducted on recovered COVID-19 patients. There were 20 multiple-choice questions, including patient demographics, treatment, and post-recovery symptoms. Chi-square and Fisher’s exact tests were used to investigate significant relationships. In addition, Binary logistic regression was performed to determine confounders. Data were analyzed using SPSS version 22.

Results:

Medications and supplements varied in their therapeutic effects on SARS-CoV-2 post-recovery symptoms. Patients who took vitamin D and calcium experienced increased symptom frequency, and patients taking ACE inhibitors experienced more headaches and coughs. Furthermore, patients receiving azithromycin were asymptomatic after recovery. Patients who took H2 antagonists reported persistent headaches and muscle pain.

Conclusion:

Patients infected with SARS-CoV-2 have responded differently to medications, multivitamins, and herbal supplements. Patients reported resolution of some symptoms and persistence of others post-recovery. Therefore, expert opinion should be considered in COVID-19 management until randomized controlled trials answer many questions and determine medications' safety and efficacy in prevention, treatment strategies, and symptoms of SARS-CoV-2 infection post-recovery.

Delivering Benefits at Speed Through Real-World Repurposing of Off-Patent Drugs: The COVID-19 Pandemic as a Case in Point

Real-world drug repurposing-the immediate "off-label" prescribing of drugs to address urgent clinical needs-is a widely overlooked opportunity. Off-label prescribing (ie, for a nonapproved indication) is legal in most countries and tends to shift the burden of liability and cost to physicians and patients, respectively. Nevertheless, health crises may mean that real-world repurposing is the only realistic source for solutions. Optimal real-world repurposing requires a track record of safety, affordability, and access for drug candidates. Although thousands of such drugs are already available, there is no central repository of off-label uses to facilitate immediate identification and selection of potentially useful interventions during public health crises. Using the current coronavirus disease (COVID-19) pandemic as an example, we provide a glimpse of 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 targeted toward the underlying pathophysiology that makes COVID-19 so deadly. This paper briefly summarizes why cimetidine or famotidine, dipyridamole, fenofibrate or bezafibrate, and sildenafil citrate are worth considering for patients with COVID-19. Clinical trials to assess efficacy are already underway for famotidine, dipyridamole, and sildenafil, and further trials of all these agents will be important in due course. These examples also reveal the unlimited opportunity to future-proof our health care systems by proactively mining, synthesizing, cataloging, and evaluating the off-label treatment opportunities of thousands of safe, well-established, and affordable generic drugs.

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.

What is the optimum prophylaxis against gastrointestinal haemorrhage for patients undergoing adult cardiac surgery: histamine receptor antagonists, or proton-pump inhibitors?

A best evidence topic was written according to a structured protocol. The question addressed was what is the optimum prophylaxis against gastrointestinal haemorrhage for patients undergoing adult cardiac surgery: histamine receptor antagonists (H(2)RA) or proton-pump inhibitors? A total of 201 papers were found; of which, 8 represented the best evidence. The authors, date, journal, study type, population, main outcome measures and results were tabulated. Only one randomized controlled trial (RCT) with relevant clinical outcomes was identified. The rest of the studies consisted of five prospective studies and two retrospective studies. In the RCT, there were no reported cases of gastrointestinal haemorrhage in the proton-pump inhibitor cohort, whereas 4 patients taking H(2)RA developed it. The rate of active gastrointestinal ulceration was higher in the H(2)RA cohort in comparison with the proton-pump inhibitor cohort (21.4 vs 4.3%). A prospective study followed 2285 consecutive patients undergoing cardiac surgery who received either no prophylaxis, or a proton-pump inhibitor. Chi-squared analysis showed the risk of bleeding to be lower in those receiving the proton-pump inhibitor (P < 0.05). Another study of 6316 patients undergoing coronary artery bypass grafting demonstrated a reduced risk of gastrointestinal bleed with prophylactic intravenous omeprazole (odds ratio = 0.2; confidence intervals = 0.1-0.8; P < 0.05). One study successfully showed that proton-pump inhibitors are effective in adequately suppressing gastric acid levels, regardless of Helicobacter pylori infection status; conversely, this study suggested that H(2)RAs were not. The evidence for H(2)RAs is marginal, with no study showing a clear benefit. One study showed that ulcer prophylaxis with H(2)RA did not correlate with the clinical outcome. Another study demonstrated gastric ulceration to be a common gastrointestinal complication in spite of regular H(2)RA use. There is also evidence to suggest that acid suppression increases the risk of nosocomial pneumonia, although open heart surgery may be a confounding factor in this association. Two RCTs showed that H(2)RAs may augment the immune system and reducing stress following cardiac surgery. Proton-pump inhibitors appear to be the superior agent for prophylaxis against gastrointestinal bleed in patients undergoing cardiac surgery, although rigorous comparative data are sparse. Furthermore, level-I evidence would confirm this.

Is routine stress ulcer prophylaxis of benefit for patients undergoing cardiac surgery?

A best evidence topic in cardiac surgery was written according to a structured protocol. We address whether routine pharmacological stress ulcer prophylaxis is of benefit for patients undergoing cardiac surgery. One hundred and fifty-six papers were found using the reported search, of which 10 represented the best evidence to answer the clinical question. The authors, journal, date, country of publication, patient group, study type, relevant outcomes and results of these papers were tabulated. The results show that the incidence of stress ulcers following cardiac surgery is low (0.45%), but remains associated with significant morbidity and mortality. Five of the 7 studies demonstrated suppression of acid secretion or decreased incidence of gastric complications in patients given pharmacological stress ulcer prophylaxis, with the remaining two suggesting no clinical benefit. One prospective study of 210 patients, randomized equally between a proton pump inhibitor (PPI), histamine antagonist and teprenone, found that PPIs were the most effective at reducing gastric complications after cardiac surgery, including ulcer formation and upper gastrointestinal bleeding (UGIB). However, a separate retrospective study suggested no difference in the outcomes between the use of a PPI and a histamine antagonist. Of the studies focused on histamine antagonists, one randomized control trial (RCT) showed that cimetidine can reduce surgical stress, augment the immune system and reduce the intubation time after cardiac surgery, although no direct association with UGIB was made. A second prospectively randomized study of histamine antagonists demonstrated superior pH control with famotidine and ranitidine, when compared with cimetidine. Furthermore, haematological and neurological side-effects were noted only with the use of cimetidine. A recent meta-analysis and systematic review of the literature associated gastric acid suppression with an increased risk of pneumonia. Two prospective cohort studies that examined the use of PPI in conjunction with clopidogrel in patients with coronary artery disease concluded that there was no association with an increase in major adverse cardiovascular events with the use of PPIs. We conclude that the current evidence is marginally in favour of the use of prophylactic PPIs. However, this is associated with an increased risk of hospital-acquired pneumonia.

Effects of cimetidine, a histamine type 2 receptor antagonist, on microcirculatory disturbance of the stomach induced by full-thickness burn injuries as a model for surgical stress in rats

BACKGROUND

We have reported the preventive effect of cimetidine, a histamine type 2 receptor antagonist, on decreased gastric mucosal blood flow induced by burn injury, a model of surgical stress.

OBJECTIVE

The present study was performed to assess the effects of cimetidine on gastric microcirculatory disturbance induced by surgical stress.

METHODS

Twelve male Wistar rats were anesthetized and a 30% full-thickness dorsal scald burn was inflicted. The total lengths of gastric erosions were measured using stereoscopic microscopy. Microvascular images in the basal region of the gastric mucosa were observed using an intravital microscope, and the diameters of venules and collecting venules were measured. Rolling leukocytes inside and along the venules, an indication of endothelial damage to the microcirculation, were observed. The rats were assigned to the cimetidine group or the control group (both, n = 6). Cimetidine 100 mg/kg was administered 30 minutes before and 2.5 hours after infliction of the burn injury. Animals in the control group were given only isotonic saline. Values are expressed as mean (SD).

RESULTS

Contraction of venules was easily observed in all rats in the control group. However, venular contraction was rarely observed in the cimetidine group. The total length of gastric erosions was significantly decreased in the cimetidine group compared with the control group (0.93 [0.58] μm vs 5.98 [5.18] μm, respectively; P < 0.05). The percentages of rolling leukocytes that passed the confluence of a prevenule and a venule were also significantly decreased in the cimetidine group compared with the control group (4.7% [7.3%] vs 22.6% [5.7%]; P < 0.01). The diameters of the venules and collecting venules were significantly larger in the cimetidine group (57.3 [6.8] μm and 75.9 [3.6] μm, respectively) than in the control group (30.9 [9.2] μm and 46.8 [8.0] μm, respectively) (both, P < 0.01).

CONCLUSIONS

The present study suggests that cimetidine may have a protective effect against gastric microcirculatory disturbances induced by burn injury, a model of surgical stress.

Perioperative cimetidine administration promotes peripheral blood lymphocytes and tumor infiltrating lymphocytes in patients with gastrointestinal cancer: Results of a randomized controlled clinical trial

AIM: To study the effects of perioperative administration of cimetidine (CIM) on peripheral blood lymphocytes, natural killer (NK) cells and tumor infiltrating lymphocytes (TIL) in patients with gastrointestinal (GI) cancer.

METHODS: Forty-nine GI cancer patients were randomized into treatment group, who took CIM in perioperative period, and control group, who did not take the drug. The treatment was initiated 7 days before operation and continued for 10 days after surgery. At baseline examination before operation, on the 2nd and 10th postoperative days, total T lymphocytes, T helper cells, T suppressor cells, and NK cells in peripheral blood were measured respectively by immunocytochemical method using mouse-anti human CD₃, CD₄, CD₈ and CD₅₇ monoclonal antibodies. Blood samples from 20 healthy volunteers were treated in the same way as normal controls. Surgical specimens were examined during routine histopathological evaluation for the presence of TIL in tumor margin. Immunohistochemical study was performed to measure the proportion of T and B lymphocytes in TIL population. T and B lymphocytes were detected respectively using mouse-anti-human CD₃ and CD₂₀ monoclonal antibodies.

RESULTS: In comparison with normal controls, both the treatment and control groups had decreased T cells, T helper cells and NK cells at baseline. In control group, total T cells, T helper cells and NK cells declined continuously with the disease progression and the decrease became more obvious after operation. From baseline to the 2nd postoperative day, the proportion of total T cells, T helper cells, and NK cells went down from 60.5 ± 4.6% to 56.2 ± 3.8%, 33.4 ± 3.7% to 28.1 ± 3.4%, and 15.0 ± 2.8% to 14.2 ± 2.2%, respectively. On the other hand, there were significant improvements in these parameters after CIM treatment. On the 10th postoperative day, the treatment group had significantly higher percentages of total T cells, T helper cells and NK cells than control group. Moreover, CIM treatment also boosted TIL response, as was reflected by findings that 68%(17/25) of the patients in treatment group had significant TIL responses and only 25% (6/24) of the cases had discernible TIL responses (P < 0.01).

CONCLUSION: Perioperative application of CIM to GI cancer patients could help restore the diminished cellular immunity induced by tumor burden and surgical maneuver. The drug could also boost TIL responses to tumor. These effects suggest that the drug be used as an immunomodulator for GI cancer patients.

A review of anti-inflammatory strategies in cardiac surgery

It is generally accepted that cardiac surgery is frequently associated with the development of systemic inflammatory response. This phenomenon is very variable clinically, and can be detected by measuring plasma concentrations of certain inflammatory markers. Complement component, cytokines and adhesion molecules are examples of these markers. Systemic inflammation can be potentially damaging to major organs. Several anti-inflammatory strategies have been used in recent years, aiming to attenuate the development of systemic inflammatory response. This article summarizes recently published literature concerning the use of anti-inflammatory techniques and pharmacological agents in cardiac surgery. In particular, the anti-inflammatory effects of off-pump surgery, leukocyte filtration, corticosteroids, aprotinin, phosphodiesterase inhibitors, dpoexamine, H2 antagonists and ACE inhibitors are reviewed. The overall conclusion is that although certain strategies reduce plasma levels of inflammatory mediators, convincing evidence of significant clinical benefits is yet to come.