Amiodarone—Avoid the danger of Torsade de Pointes

Temporary atrial overdrive pacing during a drug-refractory electrical storm in acute myocardial infarction

A 64-year-old man with diabetes mellitus was diagnosed with a non-ST-segment elevation myocardial infarction and was treated with stent implantation. Four days later, he developed an electrical storm (ES) that persisted despite antiarrhythmic drugs and sedation. External defibrillation was performed more than 100 times over 2 hours. After ruling out the common causes of polymorphic ventricular tachycardia, an ES was considered because of brady-dependent R-on-T phenomenon, presumably precipitated by antiarrhythmic drugs. Temporary transvenous atrial overdrive pacing allowed complete suppression of premature ventricular complexes and ventricular fibrillation.

The risk of cardiac events in patients who received concomitant levofloxacin and amiodarone

OBJECTIVES

Levofloxacin and amiodarone are both known to prolong the QT interval. This study was conducted to estimate the risk of cardiac events in patients receiving concomitant levofloxacin and amiodarone.

METHODS

The study included patients who were admitted to a large academic community medical center from 1/2012 to 12/2015 and received both levofloxacin and amiodarone at some point during their hospitalization. Patients received concomitant or non-concomitant levofloxacin and amiodarone during hospitalization. The primary outcome was the occurrence of cardiac events during therapy. The secondary outcome was the proportion of patients with an electrocardiogram performed before and after initiation of therapy. Odds ratios for cardiac events were calculated using a multivariable logistic regression model with and without adjusting for the study variables. The concomitant group was further evaluated for predictors of the primary outcome using multivariable logistic regression.

RESULTS

This study included 240 patients, 164 (68.3%) of whom received concomitant levofloxacin and amiodarone. Concomitant medication therapy was associated with a greater than six-fold increased risk of cardiac events after adjusting for the study variables (Odds Ratio=6.20; 95% Confidence Interval=1.34-28.62).

CONCLUSIONS

Patients receiving concomitant amiodarone and levofloxacin experienced a five-fold increase in cardiac events compared to patients given either medication alone.

Potentially inappropriate medications in the elderly: a comprehensive protocol

Elderly patients are at increased risk of drug-related morbidity and mortality. Avoiding the use of potentially inappropriate medications (PIMs) is one of the strategies that has been widely adopted to reduce the harmful consequences of drug use. There are several PIM screening tools available. In this review, we provide an overview of existing screening tools to detect PIMs in the elderly, emphasizing the advantages and disadvantages of each. Combining previously published and adopted tools (adjusted Beers list, French consensus panel, McLeod's list, and Lindblad's list of clinically important drug-disease interactions), we develop a new comprehensive tool that also includes the adjusted Hanlon's and Malone's lists of potentially serious drug-drug interactions in the elderly. In addition to listed PIMs and clinically important drug-drug interactions, alternative therapeutic solutions are suggested. The new protocol differentiates: drugs with an unfavorable benefit/risk ratio (to be avoided regardless of the underlying disease/condition), drugs with a questionable efficacy, and drugs to be avoided with certain diseases/conditions, and provides a list of potentially serious drug-drug interactions. A tool consisting of PIMs and potential drug-drug interactions within the same protocol provides more comprehensive quality assessment of drug-prescribing behavior to the elderly, which in turn may lead to better prescribing practices.

Amiodarone for the emergency care of children

Amiodarone is a class 3 antiarrhythmic agent used for a broad range of arrhythmias including adenosine-resistant supraventricular tachycardia, junctional ectopic tachycardia, and ventricular tachycardia. Compared with adults, there are few data on its use in children with arrhythmias resistant to conventional therapy. National and international guidelines for cardiopulmonary resuscitation and emergency cardiovascular care recommend its use for a variety of arrhythmias based on case reports, cohort studies, and extrapolation from adult data. This article will review the historical development, chemical properties, metabolism, indications and contraindications, and adverse effects of amiodarone in infants and children. After completing this CME activity, the reader should be able to utilize amiodarone in the pediatric population for arrhythmias and identify complications associated with its use.

Survival after prolonged resuscitation with 99 defibrillations due to Torsade De Pointes cardiac electrical storm: a case report

A 48-year-old previously healthy woman suffered witnessed cardiac arrest in hospital. She achieved return of spontaneous circulation and was transferred to the intensive care unit. During the following 3 hours, she suffered a cardiac electrical storm with 98 episodes of Torsade de Pointes ventricular tachycardia rapidly degenerating to ventricular fibrillation. She was converted with a total of 99 defibrillations. There was no response to the use of any recommended anti arrhythmic drugs. However, the use of bretylium surprisingly stabilized her heart rhythm and facilitated placing of a temporary pacemaker. Overdrive pacing prevented further arrhythmias and was life saving. A number of beneficial factors may have contributed to the good neurological outcome. Further investigations gave no explanation for her cardiac electrical storm.

Long QT syndrome and torsades de pointes induced by acute sulpiride poisoning

Sulpiride, a selective dopamine D2 antagonist and a substituted benzamide derivative, is considered a safe antipsychotic and antidepressant agent with few adverse effects on the cardiovascular system. Sulpiride-induced torsades de pointes is rare. We report a case of long QT syndrome and torsades de pointes induced by ingestion of 1.5 g of sulpiride. Ventricular arrhythmia was initially treated with amiodarone, without success. Eventually, lidocaine and magnesium sulfate successfully terminated the ventricular arrhythmia. The patient was discharged uneventfully after 3 days of hospitalization. This case illustrates the fact that acute sulpiride poisoning may lead to life-threatening ventricular arrhythmia. Early recognition followed by effective therapy is crucial. Intensive cardiac monitoring is recommended for sulpiride poisoning.