Assessment of the risk of QT-interval prolongation associated with potential drug-drug interactions in patients admitted to Intensive Care Units

Potential QT-prolonging drug-drug interactions in cardiovascular disease patients

Abstract The study aimed to assess the prevalence and characteristics of potential drug-drug interactions (pDDIs) that increase the risk of QT prolongation, in a population of cardiovascular disease patients. An observational retrospective study was conducted at a cardiology ward. A total of 351 patients were included in the analysis, with almost equal gender distribution (female 48.4%) and mean age 70±10 years. In the total set of tested drug pairs (5620), QT-prolonging pDDIs were identified in 13 drug pairs on admission. The highest frequency was observed for ciprofloxacin (involved in 5 pDDIs), followed by propafenone (4 pDDIs) and beta2-agonists (4 pDDIs). The pharmacodynamic mechanism was involved in all pDDIs. The study revealed a low prevalence of QT-prolonging pDDIs on admission to the cardiology ward, about 3% in the studied population. However, given that underlying heart disease is a significant risk factor for the occurrence of QTc prolongation, the additional risk for acquired QT prolongation should not be neglected. Due to serious consequences caused by QT prolongation and TdP, the key role of health professionals is to identify predisposed patients and to recognize pDDIs involving QT-prolonging agents. Hence, patients’ modifiable risk factors for QT prolongation should be minimized, if not eliminated.

The Association of Proton Pump Inhibitors and QT Interval Prolongation in Critically Ill Patients

INTRODUCTION

Drug-induced QT interval prolongation has been reported to be related to life-threatening polymorphic ventricular tachycardia (torsade de pointes). Proton pump inhibitors (PPIs) are prescribed widely for hospitalized patients; the QT interval prolongation and torsade de pointes caused by PPIs were reported. We conducted a study to determine the association between PPI treatment and QT interval prolongation in critically ill patients.

METHODS

This study included patients with electrocardiography (ECG) reports from the Medical Information Mart for Intensive Care III database (MIMIC-III). Patients younger than 18 years, missing baseline laboratories and with QT interval prolongation before intensive care unit (ICU) admission were excluded. The end point was the diagnosis of QT interval prolongation reported by ECG.

RESULTS

This study included 24,512 ICU patients. Of them, 11,327 patients were treated with PPIs, 4181 with histamine 2 receptor antagonists (H2RAs) and 6351 without acid suppression therapy (non-AST); the incidence of QT interval prolongation were 8.5%, 3.3% and 3.4% respectively. After adjustment for demographics, electrolytes, comorbidities and medications, PPIs were associated a higher risk of QT interval prolongation compared with H2RAs (OR 1.66, 95% CI 1.36 - 2.03) and non-AST (OR 1.54, 95% CI 1.31 - 1.82), while there was not significant difference between H2RAs and non-AST (OR 0.93, 95% CI 0.73 - 1.17). In the propensity score matching population, the results were consistent. Pantoprazole (OR 2.14, 95% CI 1.52 - 3.03) and lansoprazole (OR 1.80, 95% CI: 1.18 - 2.76) showed a higher QT prolongation risk than omeprazole. Several drugs caused higher QT prolongation risk when used in combination with PPIs.

CONCLUSION

In ICU patients, the association between PPI prescription and increased risk of QT interval prolongation was independent of known QT-prolonging factors; pantoprazole and lansoprazole had a higher risk compared with omeprazole. The combination of PPIs and other QT-prolonging drugs should be avoided.

Total Intravenous Anaesthesia for Laparoscopic Cholecystectomy in a Patient With Congenital Long QT Syndrome: A Case Report

Long QT syndrome (LQTS) is characterised by QT interval prolongation and ventricular arrhythmia, leading to sudden cardiac death. Patients with acquired or congenital LQTS pose special challenges to anaesthetists perioperatively due to the risk of developing life-threatening arrhythmia. A variety of medications, including commonly used volatile anaesthetic agents are known to prolong QT interval and there has been growing evidence of using total intravenous anaesthesia (TIVA) instead of volatile agents for such patients.  This is a case report of a 30-year-old patient with congenital LQTS and subcutaneous implantable cardioverter defibrillator (SICD) in situ who underwent laparoscopic cholecystectomy and endoscopic retrograde cholangiopancreatography (ERCP) under TIVA safely within two months. There were no arrhythmic events observed perioperatively.  This case highlights the importance of comprehensive planning and meticulous preparation to avoid all possible QT-prolonging conditions during the perioperative period, especially in patients with acquired or congenital LQTS.

Drug-Induced Enterocolitis Syndrome in Children

Drug-Induced Enterocolitis Syndrome (DIES) is a drug-induced hypersensitivity reaction non-IgE mediated involving the gastrointestinal system that occurs 2 to 4 h after drug administration. Antibiotics, specifically amoxicillin or amoxicillin/clavulanate, represent the most frequent drugs involved. Symptoms include nausea, vomiting, abdominal pain, diarrhea, pallor, lethargy, and dehydration, which can be severe and result in hypovolemic shock. The main laboratory finding is neutrophilic leukocytosis. To the best of our knowledge, 12 cases of DIES (9 children-onset and 3 adult-onset cases) were described in the literature. DIES is a rare clinically well-described allergic disease; however, the pathogenetic mechanism is still unclear. It requires to be recognized early and correctly treated by physicians.

Vomiting, electrolyte disturbance, and medications; the perfect storm for acquired long QT syndrome and cardiac arrest: a case report

Background

Acquired long QT syndrome is an important and preventable cause of cardiac arrest. Certain medications and electrolyte disturbance are common contributors, and often coexist. In this case, we report five contributors to cardiac arrest.

Case presentation

This case is of a 51-year-old Caucasian female patient who presented with vomiting associated with hypokalemia and hypomagnesemia. She subsequently received ondansetron and metoclopramide, on the background of chronic treatment with fluoxetine. She then suffered an in-hospital monitored cardiac arrest, with features of long QT and torsades de pointes retrospectively noted on her prearrest electrocardiogram. She was diagnosed with acquired long QT syndrome, and her QT interval later normalized after removal of offending causes.

Conclusions

This case highlights the importance of proper consideration prior to prescribing QT prolonging medications, especially in patients who have other risk factors for prolonged QT, such as electrolyte disturbances and pretreatment with QT prolonging medications.