Clinical aspects of cardiovascular effects of H2-receptor antagonists

Intravenous ranitidine injection and risk of cardiac arrest: Medication errors

BACKGROUND

Ranitidine injection is not well-known to cause cardiac arrest except in few published case reports. The Eritrean Pharmacovigilance Centre received four cases of cardiac arrest associated with ranitidine injection.

OBJECTIVE

To assess the causal relationship between cardiac arrest and ranitidine, and to identify possible risk factors.

METHODS

This is a descriptive case series assessment of cardiac arrest associated with ranitidine and data was mined to supplement the cases from the WHO global database of individual case safety reports.

RESULTS

In all cases, ranitidine injection was administered fast IV bolus without proper dilution and the outcome was fatal in three. All patients encountered cardiac arrest within 20 minutes of intravenous use. Causality was found to be probable in two cases and possible in the other two. Cardiac arrest could have been prevented in all cases. On top of this, from the WHO global database, 185 cases of cardiac arrest and cardio-pulmonary arrest associated with ranitidine were retrieved and 49.7% were fatal. In 40% of the cases, ranitidine was reported as a single suspect. In 36 cases, cardiac arrest resolved following withdrawal of ranitidine and reaction recurred in one case after re-introduction of the product.

CONCLUSION

There appears a causal link between ranitidine and cardiac arrest, possibly related to medication errors that warrants immediate attention from healthcare professionals.

Association Between Proton Pump Inhibitors and Asthma: A Population-Based Cohort Study

Objective

The relationship between proton pump inhibitors (PPIs) and asthma is controversial. The goal of this study was to determine the association between PPI use in non-asthma subjects and their subsequent asthma prevalence.

Design

Nationwide, population-based cohort study.

Methods

We conducted a nationwide, population-based retrospective cohort study using data from the National Health Insurance Research Database (NHIRD) of Taiwan from 1999 to 2013. We identified 24,077 adult patients with PPI use for more than 3 months and 24,077 controls matched by propensity score on a one-to-one ratio for age, gender, comorbidities (hypertension, hyperlipidemia, gastroesophageal reflux disease, allergic rhinitis, atopic dermatitis, peptic ulcer disease, diabetes, and sleep apnea syndrome), and medications (histamine 2 receptor antagonists [H2RA], nonsteroidal anti-inflammatory drugs [NSAIDs], and acetaminophen). The cumulative asthma incidence for the two cohorts in the follow-up period was estimated with the Kaplan-Meier method, and the difference was examined using the log-rank test. Multivariate Cox regression models were used to calculate the adjusted hazard ratios (HR).

Results

The overall incidence of asthma was 1.58-fold greater in the PPI cohort than in the non-PPI cohort (13.3 versus 8.4 per 1,000 person-years), with an adjusted HR of 1.76 (95% confidence interval [CI], 1.64-1.88). In patients without previous peptic ulcer disease, the adjusted HR of asthma associated with PPIs was higher than in the non-PPI group (1.95; 95% CI, 1.80-2.11). The risk of asthma due to PPI use was also more significant in patients not receiving H2RA (1.81; 95% CI, 1.66-1.96), NSAIDs (1.93; 95% CI, 1.73-2.15), and acetaminophen (1.88; 95% CI, 1.70-2.08).

Conclusions

This population base study demonstrated that patients with long-duration of PPI use are at a higher risk of developing asthma, regardless of age, gender, comorbidities, and medications.

Gastroduodenal Ulceration in Small Animals: Part 2. Proton Pump Inhibitors and Histamine-2 Receptor Antagonists

In the first part of this review, we discussed the pathophysiology and epidemiology of gastric acid secretion and the epidemiology of gastroduodenal ulceration in dogs and cats. In this section, we discuss the pharmacology and evidence-based clinical use of histamine-2 receptor antagonists and proton pump inhibitors.

Can negative cardiac effect of proton pump inhibitor and high-dose H2-blocker have clinical influence on patients with stable angina?

BACKGROUND

Aspirin and anti-platelet drugs are used commonly for patients with coronary heart disease. Proton pump inhibitor (PPI) and high-dose H2-blocker were recommended for preventing NSAIDs-related ulcer. Previously H2-blocker reported to have some negative cardiovascular effects. Additionally, a recent in vitro study showed that PPI reduced cardiac contractility. In this study, we evaluated whether chronic administration of PPI and high-dose H2-blocker affects left ventricular function.

METHOD

Fifty-two stable angina patients were enrolled and classified into PPI group ([P]; lansoprazole: 15 mg/day, n=28), H2-blocker group ([H]; famotidine: 40 mg/day, n=8), and control ([C]; none or mucosal-defense drug, n=16). Eligible patients showed normal cardiac function in initial catheterization without administrated PPI or H2-blocker. They received percutaneous coronary intervention and follow-up catheterization. We compared changes in ejection fraction (EF: %), end diastolic/systolic volume index (EDVI/ESVI: ml/m(2)), and peak positive/negative dp/dt (+/-dp/dt: mmHg/s) in left ventricular angiography series.

RESULT

There were no significant differences among three groups regarding patient characteristics, backgrounds of angiographic and intervention, except for fewer smokers in [C]. Other drugs such as beta- and Ca-blocker did not have effects on cardiac function except for aspirin during 255+/-115 days follow-up. Rate of EF changes significantly decreased in [P], and tended to decrease in [H] (C: 3.8+/-9.8%, H: -1.6+/-7.6%, P: -2.1+/-5.9%; p<0.05 for [C] vs. [P]). Those of ESVI changes were significantly greater in [P], and tended to be greater in [H] (C: -4.5+/-16.2%, H: 4.9+/-15.5%, P: 7.3+/-16.2%; p<0.05 for [C] vs. [P]), though, EDVI changes' were similar (C: 2.5+/-8.9%, H: 2.6+/-3.6%, P: 1.6+/-6.1%; p=ns). Rate of +/-dp/dt-changes tended to decrease in [H] (+dp/dt: C: 3.9+/-15.5%, H: -10.0+/-25.2%, P: 0.3+/-19.6%; p=ns, -dp/dt: C: -0.1+/-19.5%, H: -8.5+/-20.4%, P: 5.7+/-27.7%; p=ns).

CONCLUSION

In this study, PPI and high-dose H2-blocker have EF-reducing tendency. However, these changes were small and these drugs seemed to exhibit little influence clinically.

Pharmacotherapy for chronic gastro-oesophageal reflux disease and Barrett's oesophagus

Over the last two decades there have been major advances in the medical treatment of gastro-oesophageal reflux disease (GORD) and Barrett's oesophagus. Motility agents, H(2)-receptor antagonists and proton-pump inhibitors (PPI) have all been evaluated in short- and long-term studies. Symptomatic response needs to be differentiated from healing of oesophagitis and maintenance of remission. Clinical trials have convincingly demonstrated the superiority of PPIs to motility agents and H(2)-receptor antagonists for all clinical aspects of GORD. Barrett's oesophagus requires lifelong acid suppression. Treatment with standard doses of PPIs is often insufficient and higher doses are frequently required. Medical treatment does not appear to result in clinically significant regression of Barrett's oesophagus.

Bradycardia associated with intravenous methadone administered for sedation in a patient with acute respiratory distress syndrome

The use of low tidal volumes with permissive hypercapnia in patients with acute respiratory distress syndrome may require heavy sedation to allow them to tolerate mechanical ventilation. Administration of methadone for sedation is an alternative to using other opioids, given its longer elimination half-life and incomplete cross-tolerance with other mu-receptor-active opioids. Methadone appears to have a molecular structure similar to that of verapamil, a calcium channel blocker, and may exhibit similar cardiac properties as well. A 43-year-old man with acute respiratory distress syndrome experienced bradycardia while receiving a continuous infusion of methadone for sedation and mechanical ventilation management. This case report demonstrates that caution is warranted when high dosages of methadone are administered because of its potential cardiac effects.

Upper gastrointestinal tract bleeding in critically ill pediatric patients

Similar to adults, children under physiologic stress can develop an imbalance in defensive (mucosal layer, motility) and aggressive (gastric acid, bile salts, enzymes) factors responsible for maintaining a healthy gastrointestinal tract. Hypoxia in the gastrointestinal tract likely disrupts the defensive factors, thereby permitting damage by aggressive factors to upper gastrointestinal epithelium that may progress to stress ulceration and acute upper gastrointestinal tract bleeding (UGIB). The basic pathophysiology may be similar in children and adults; however, differences in the time to developing ulceration, ulcer location, and number of ulcers have been reported. Functional development of the gastrointestinal tract is influenced by disease, gestational and postnatal age, and exposure to and type of enteral feedings, thereby confounding the development and prophylaxis of UGIB in neonates and infants. In addition, pharmacotherapy decisions are often complicated by drug administration issues and adverse effects.

Current guidelines on stress ulcer prophylaxis

Acute uppergastrointestinal bleeding in intensive care unit (ICU) patients may occur due to peptic ulcer disease, adverse drug effects, gastric tube lesions, acute renal failure, liver failure or stress-induced gastric mucosal lesions. Gastric acid hypersecretion can be observed in patients with head trauma or neurosurgical procedures. Gastric mucosal ischaemia due to hypotension and shock is the most important risk factor for stress ulcer bleeding. Preventive strategies aim to reduce gastric acidity (histamine H2 receptor antagonists, antacids), strengthen mucosal defensive mechanisms (sucralfate, antacids, pirenzepine) and normalise gastric mucosal microcirculation (sucralfate, pirenzepine). However, the most important prophylactic measure is an optimised resuscitation and ICU regime aiming to improve oxygenation and microcirculation. All drugs approved for stress ulcer prophylaxis in Europe (H2 antagonists, antacids, pirenzepine, sucralfate) have been shown to be effective in prospective controlled randomised trials. However, due to insufficient clinical data, prostaglandins and omeprazole cannot be recommended for this use. Stress ulcer prophylaxis is indicated only in patients at risk, and not in every ICU patient. The selection of drugs today depends not only on efficacy but also on possible adverse effects and on costs. In this regard, the most cost-effective drug is sucralfate. The clinical relevance of nosocomial pneumonia due to gastric bacterial overgrowth has decreased during the past decade due to several changes in the management of critically ill patients.