Effect of Histamine H2 Receptor Antagonists on All-Cause Mortality in Critically Ill Patients With Essential Hypertension: A Retrospective Cohort Study

Previous studies found that histamine H2 receptor antagonists (H2RAs) had blood pressure lowering and cardioprotective effects, but the impact of H2RAs on the survival outcomes of critically ill patients with essential hypertension is still unclear. The aim of this study was to investigate the association of H2RAs exposure with all-cause mortality in patients with essential hypertension based on Medical Information Mart for Intensive Care III database. A total of 17,739 patients were included, involving 8482 H2RAs users and 9257 non-H2RAs users. Propensity score matching (PSM) was performed to improve balance between 2 groups that were exposed to H2RAs or not. Kaplan-Meier survival curves were used to compare the cumulative survival rates and multivariable Cox regression models were performed to evaluate the association between H2RAs exposure and all-cause mortality. After 1:1 PSM, 4416 pairs of patients were enrolled. The results revealed potentially significant association between H2RAs exposure and decreased 30-day, 90-day, and 1-year mortalities in multivariate analyses (HR = 0.783, 95% CI: 0.696-0.882 for 30-day; HR = 0.860, 95% CI: 0.778-0.950 for 90-day; and HR = 0.883, 95% CI: 0.811-0.961 for 1-year mortality, respectively). Covariate effect analyses showed that the use of H2RAs was more beneficial in essential hypertension patients with age ≥ 60, BMI ≥ 25 kg/m2, coronary arteriosclerosis, stroke, and acute kidney failure, respectively. In conclusion, H2RAs exposure was related to lower mortalities in critically ill patients with essential hypertension, which provided novel potential strategy for the use of H2RAs in essential hypertension patients.

Histamine H2 receptor antagonist exhibited comparable all-cause mortality-decreasing effect as β-blockers in critically ill patients with heart failure: a cohort study

Background: Our previous study reported that histamine H2 receptor antagonists (H2RAs) exposure was associated with decreased mortality in critically ill patients with heart failure (HF) through the same pharmacological mechanism as β-blockers. However, population-based clinical study directly comparing the efficacy of H2RAs and β-blockers on mortality of HF patients are still lacking. This study aims to compare the association difference of H2RAs and β-blockers on mortality in critically ill patients with HF using the Medical Information Mart for Intensive Care III database (MIMIC-III). Methods: Study population was divided into 4 groups: β-blockers + H2RAs group, β-blockers group, H2RAs group, and Non-β-blockers + Non-H2RAs group. Kaplan-Meier curves and multivariable Cox regression models were employed to evaluate the differences of all-cause mortalities among the 4 groups. Propensity score matching (PSM) was used to increase comparability of four groups. Results: A total of 5593 patients were included. After PSM, multivariate analyses showed that patients in H2RAs group had close all-cause mortality with patients in β-blockers group. Furthermore, 30-day, 1-year, 5-year and 10-year all-mortality of patients in β-blockers + H2RAs group were significantly lower than those of patients in β-blockers group, respectively (HR: 0.64, 95%CI: 0.50-0.82 for 30-day; HR: 0.80, 95%CI: 0.69-0.93 for 1-year mortality; HR: 0.83, 95%CI: 0.74-0.93 for 5-year mortality; and HR: 0.85, 95%CI: 0.76-0.94 for 10-year mortality, respectively). Conclusion: H2RAs exposure exhibited comparable all-cause mortality-decreasing effect as β-blockers; and, furthermore, H2RAs and β-blockers had additive or synergistic interactions to improve survival in critically ill patients with HF.

Effectiveness and Safety of Histamine H2 Receptor Antagonists: An Umbrella Review of Meta-Analyses

Histamine H2 receptor antagonists (H2RAs) were widely used to inhibit gastric acid secretion, but its association with adverse events remains controversial and unclear. We conducted an umbrella review of meta-analyses to systematically assess the quality and credibility of the correlations between H2RA use with the risk of adverse outcomes through searching 4 major databases from inception to April 30, 2022. Forty-six individual meta-analyses were identified, including 29 meta-analyses of observation studies with 32 unique outcomes and 19 meta-analyses of randomized controlled trials with 3 unique outcomes for comparing the H2RA versus non-H2RA group. A Measurement Tool to Assess Systematic Reviews 2 rating for the included meta-analyses showed that 4 of 46 meta-analyses were assigned as high scores, 3 were assigned as "moderate," and 25 were assigned as low scores. Grading of Recommendations Assessment, Development and Evaluation assessment for combined results demonstrated that 6 outcomes were rated as "moderate," 9 outcomes were rated as "low," and 17 outcomes were rated as "very low." We confirmed significant associations of H2RA use with pneumonia, peritonitis, necrotizing enterocolitis, Clostridium difficile infection, liver cancer, gastric cancer, and hip fracture diseases. No associations for colorectal cancer, melanoma, kidney cancer, lung cancer, or common reproductive system cancer or renal, neurological, and cardiovascular system diseases were observed. We found a variety of evidence for the associations between H2RAs and adverse outcomes, which would give clinicians more positive guidance on prescription of H2RAs in clinical practice.

Histamine H2 receptor antagonist exposure was related to decreased all-cause mortality in critical ill patients with heart failure: a cohort study

BACKGROUND

Previous studies reported that histamine H2 receptor antagonists (H2RAs) had cardioprotective effects. However, the effect of H2RAs on mortality of critical ill patients with heart failure (HF) remains unclear. The aim of this study was to clarify the association between H2RAs and all-cause mortality of critical ill patients with HF based on Medical Information Mart for Intensive Care III database (MIMIC-III).

METHODS

Propensity score matching (PSM) was applied to account for the baseline differences between two groups that exposed to H2RAs or not. The study primary outcome was all-cause mortality. Kaplan-Meier curves and multivariable Cox regression models were employed to estimate the effects of H2RAs on mortality of critical ill patients with HF.

RESULTS

A total of 10 387 patients were included, involving 4440 H2RAs users and 5947 non-H2RAs users. After matching, 3130 pairs of patients were matched between H2RAs users and non-H2RAs users. The results showed significant association between H2RAs exposure and decreased 30-day, 90-day and 1-year mortality in both univariate analyses and multivariate analyses (HR = 0.73, 95%CI: 0.65-0.83 for 30-day; HR = 0.80, 95%CI: 0.72-0.89 for 90-day; and HR = 0.83, 95%CI: 0.76-0.90 for 1-year mortality, respectively) by Cox regression after PSM. Furthermore, stratified analyses revealed that the 30-day, 90-day and 1-year mortality of ranitidine users were significantly lower than those of famotidine users, respectively.

CONCLUSIONS

H2RAs exposure was associated with lower mortality in critical ill patients with HF. Furthermore, ranitidine might be superior to famotidine in reducing mortality of critical ill patients with HF.

Histamine H2 receptor radioligands: triumphs and challenges

Since the discovery of the histamine H₂ receptor (H₂R), radioligands were among the most powerful tools to investigate its role and function. Initially, radiolabeling was used to investigate human and rodent tissues regarding their receptor expression. Later, radioligands gained increasing significance as pharmacological tools in in vitro assays. Although tritium-labeling was mainly used for this purpose, labeling with carbon-14 is preferred for metabolic studies of drug candidates. After the more-or-less successful application of numerous labeled H₂R antagonists, the recent development of the G protein-biased radioligand [³H]UR-KAT479 represents another step forward to elucidate the widely unknown role of the H₂R in the central nervous system through future studies.

Associations of Acid Suppressive Therapy With Cardiac Mortality in Heart Failure Patients

Background

It has been recently reported that histamine H₂ receptor antagonists (H2RAs) are associated with impairment of ventricular remodeling and incident heart failure. In addition, favorable pleiotropic effects and adverse effects of proton pump inhibitors (PPIs) on cardiovascular disease have also been reported. We examined the associations of acid suppressive therapy using H2RAs or PPIs with cardiac mortality in patients with heart failure.

Methods and Results

In total, 1191 consecutive heart failure patients were divided into 3 groups: a non–acid suppressive therapy group (n=363), an H2RA group (n=164), and a PPI group (n=664). In the follow‐up period (mean 995 days), 169 cardiac deaths occurred. In the Kaplan–Meier analysis, cardiac mortality was significantly lower in the PPI group than in the H2RA and non–acid suppressive therapy groups (11.0% versus 21.3% and 16.8%, respectively; log‐rank P=0.004). In the multivariable Cox proportional hazards analysis, use of PPIs, but not H2RAs, was found to be an independent predictor of cardiac mortality (PPIs: hazard ratio 0.488, P=0.002; H2RAs: hazard ratio 0.855, P=0.579). The propensity‐matched 1:1 cohort was assessed based on propensity score (H2RAs, n=164; PPIs, n=164). Cardiac mortality was significantly lower in the PPI group than in the H2RA group in the postmatched cohort (log‐rank P=0.025). In the Cox proportional hazards analysis, the use of PPIs was a predictor of cardiac mortality in the postmatched cohort (hazard ratio 0.528, P=0.028).

Conclusions

PPIs may be associated with better outcome in patients with heart failure.

Ranitidine-induced anaphylaxis: clinical features, cross-reactivity, and skin testing

BACKGROUND

Histamine H2 receptor antagonists are commonly prescribed medications and are known to be well tolerated. However, 99 cases of ranitidine-induced anaphylaxis occurred in Korea from 2007 to 2014.

OBJECTIVE

The purpose of this study was to determine the incidence, clinical features, and diagnostic methods for ranitidine-induced anaphylaxis.

METHODS

Ranitidine-related pharmacovigilance data from 2007 to 2014 were reviewed. Adverse drug reactions with causal relationships were selected, and clinical manifestations, outcomes, and drug-related information were assessed. For further investigation, 8 years of pharmacovigilance data were collected at a single centre. Twenty-three patients participated in in vivo and in vitro studies. Skin tests, oral provocation tests, and laboratory tests were performed, including tests using other kinds of histamine H2 receptor antagonists.

RESULTS

Over 7 years, 584 patients suffered adverse reactions to ranitidine. The most common manifestation was cutaneous symptoms. Among them, 99 patients (17.0%) experienced anaphylaxis. In a single-centre study, skin prick tests were positive in 91.7% of ranitidine-induced anaphylaxis patients (11/12); the optimal concentration was 20 mg/mL. Detection of ranitidine-specific immunoglobulin E failed. Cimetidine and proton pump inhibitors showed no cross-reactivity with ranitidine based on the skin prick test, oral provocation test, or clinical determination. Surprisingly, 82.6% of patients reintroduced ranitidine and re-experienced the same adverse reactions because ranitidine was not considered the culprit drug.

CONCLUSIONS AND CLINICAL RELEVANCE

Although ranitidine is known as a safe drug, it can also cause diverse adverse reactions, including anaphylaxis. This study demonstrates the need to pay attention to adverse reactions to ranitidine and consider ranitidine as a cause of anaphylaxis.

A stepwise protocol for the treatment of refractory gastroesophageal reflux-induced chronic cough

BACKGROUND

Refractory gastroesophageal reflux-induced chronic cough (GERC) is difficult to manage. The purpose of the study is to evaluate the efficacy of a novel stepwise protocol for treating this condition.

METHODS

A total of 103 consecutive patients with suspected refractory reflux-induced chronic cough failing to a standard anti-reflux therapy were treated with a stepwise therapy. Treatment commences with high-dose omeprazole and, if necessary, is escalated to subsequent sequential treatment with ranitidine and finally baclofen. The primary end-point was overall cough resolution, and the secondary end-point was cough resolution after each treatment step.

RESULTS

High-dose omeprazole eliminated or improved cough in 28.1% of patients (n=29). Further stepwise of treatment with the addition of ranitide yielded a favorable response in an additional 12.6% (n=13) of patients, and subsequent escalation to baclofen provoked response in another 36.9% (n=38) of patients. Overall, this stepwise protocol was successful in 77.6% (n=80) of patients. The diurnal cough symptom score fell from 3 [1] to 1 [0] (Z=6.316, P=0.000), and the nocturnal cough symptom score decreased from 1 [1] to 0 [1] (Z=-4.511, P=0.000), with a corresponding reduction in the Gastroesophageal Reflux Diagnostic Questionnaire score from 8.6±1.7 to 6.8±0.7 (t=3.612, P=0.000). Conversely, the cough threshold C2 to capsaicin was increased from 0.49 (0.49) µmol/L to 1.95 (2.92) µmol/L (Z=-5.892, P=0.000), and the cough threshold C5 was increased from 1.95 (2.92) µmol/L to 7.8 (5.85) µmol/L (Z=-5.171, P=0.000).

CONCLUSIONS

Sequential stepwise anti-reflux therapy is a useful therapeutic strategy for refractory reflux-induced chronic cough.

Adverse effects reported in the use of gastroesophageal reflux disease treatments in children: a 10 years literature review

Gastroesophageal reflux (GER) is commonly observed in children, particularly during the first year of life. Pharmacological therapy is mostly reserved for symptomatic infants diagnosed with GER disease (GERD), usually as defined in a recent consensus statement. The purpose of the present article was to review the reported adverse effects of pharmacological agents used in the treatment of paediatric GERD. We conducted this review using the electronic journal database Pubmed and Cochrane database systematic reviews using the latest 10-year period (1 January 2003 to 31 December 2012). Our search strategy included the following keywords: omeprazole, esomeprazole, lansoprazole, pantoprazole, rabeprazole, rantidine, cimetidine, famotidine, nizatidine, domperidone, metoclopramide, betanechol, erythromycin, baclofen, alginate. We used Pubmed's own filter of: 'child: birth-18 years'. All full articles were reviewed and we only included randomized controlled trials retrieved from our search. We addressed a summary of our search on a drug-by-drug basis with regard to its mechanism of action and clinical applications, and reviewed all of the adverse effects reported and the safety profile of each drug. Adverse effects have been reported in at least 23% of patients treated with histamine H2 receptor antagonists (H2 RAs) and 34% of those treated with proton pump inhibitors (PPIs), and mostly include headaches, diarrhoea, nausea (H2 RAs and PPIs) and constipation (PPIs). Acid suppression may place immune-deficient infants and children, or those with indwelling catheters, at risk for the development of lower respiratory tract infections and nosocomial sepsis. Prokinetic agents have many adverse effects, without major benefits to support their routine use.

Differences in utilisation of gastroprotective drugs between 2001 and 2005 in Australia and Nova Scotia, Canada

PURPOSE

This study aimed to compare use of histamine H2 receptor antagonists (H2RAs) and proton pump inhibitors (PPIs), 2001-2005, in the elderly and social security beneficiaries in Australia (AUS) and Nova Scotia, Canada (NS).

METHODS

Prescription dispensing data were collected for all subsidised H2RAs and PPIs. In AUS, dispensing data for concession beneficiaries were obtained from the Pharmaceutical Benefits Scheme database. In NS, data were sourced from the Pharmacare database. Relevant population data were used to convert to World Health Organisation Anatomic Therapeutic Chemical defined daily doses (2005) per 1000 beneficiaries per day (DDD/1000/day).

RESULTS

Overall use of gastroprotective agents was similar and rising in NS and AUS (100-160 DDD/1000/day) over this 5-year time window. However, the proportion of this use accounted for by PPIs was far higher in AUS (over 85% by 2005) than in NS (23% rising to 35% over the 5 years). In AUS, PPI use rose from 50 to about 140 DDD/1000/day over the 5 years, whereas PPI use in NS rose slowly to less than 60 DDD/1000/day by 2005. H2RA use in NS was always high (over 100 DDD/1000/day), whereas in AUS, H2RA use fell from 54 to around 24 DDD/1000/day over this period.

CONCLUSIONS

AUS had much higher use of PPIs than NS over 2001-2005. The proportion of PPIs in all gastroprotective agents rose in AUS to be nearly 90%. The differences in utilisation during this time window could lead to differences in health outcomes from either lower gastro-intestinal bleeding risk or higher long-term adverse effects of PPIs.