Wide complex tachycardia after bupropion overdose

Evolving trends of pharmaceutical poisonings associated with QRS complex prolongation

INTRODUCTION

Tricyclic antidepressants often cause drug-induced QRS complex prolongation in overdose but are now less commonly prescribed. We sought to determine, among a contemporary cohort of patients, the pharmaceuticals independently associated with QRS complex prolongation in acute overdose.

METHODS

We performed secondary analysis of data from the Toxicology Investigators Consortium (ToxIC) Core Registry. We included adult patients presenting from January 2016 through March 2023 with acute or acute-on-chronic pharmaceutical exposures. The primary outcome was QRS complex prolongation >0.12 s. Secondary outcomes included cardiac arrest, death, ventricular dysrhythmia, intensive care unit admission, initiation of vasopressors, and treatment with sodium bicarbonate. We used a multivariable logistic regression model with QRS complex prolongation as the outcome and individual pharmaceuticals of interest as independent variables. We assessed yearly trends of the contribution of relevant pharmaceuticals to QRS complex prolongation since 2016.

RESULTS

Of 11,945 patients in the total cohort (median age 37 years, 6,652 [55.7%] female), 366 (3.1%) developed QRS complex prolongation. Of 9,417 patients included in the model, 290 (3.1%) developed QRS complex prolongation. Amitriptyline, nortriptyline, doxepin, imipramine, noxiptiline, bupropion, flecainide, carvedilol, propranolol, diphenhydramine, and lamotrigine poisonings were independent predictors of QRS complex prolongation. Flecainide poisoning conferred the greatest odds of QRS complex prolongation (OR 574.1; 95% CI: 88.3-12,747). The contribution of tricyclic antidepressants to QRS complex prolongation decreased from 38.8% to 17.6% of all patients with QRS complex prolongation from 2016 to 2022. In 2022, the proportion of QRS complex prolongation from diphenhydramine (20.6%) surpassed that of tricyclic antidepressants.

DISCUSSION

This study provides insights into contemporary pharmaceutical poisoning associated with QRS complex prolongation. Tricyclic antidepressants remain clinically relevant exposures but are no longer the most common cause of drug-induced QRS complex prolongation.

CONCLUSIONS

Bupropion, diphenhydramine, and antidysrhythmics are increasingly common causes of QRS complex prolongation, each associated with numerous severe outcomes in poisoning. Greater safety measures to protect patients from cardiovascular toxicity from these pharmaceuticals are warranted.

Predicting adverse cardiovascular events in emergency department patients with bupropion overdose

OBJECTIVES

Bupropion toxicity can lead to adverse cardiovascular events (ACVE), but delayed onset of toxicity makes risk stratification difficult. This study aimed to validate previously defined predictors of ACVE and identify novel predictors among patients presenting to the emergency department (ED) after bupropion overdose.

METHODS

This secondary analysis of prospective data from the Toxicology Investigators Consortium Core Registry analyzed adult acute or acute-on-chronic bupropion exposures from 2015 to 2018. The primary outcome was ACVE (any of the following: myocardial injury, shock, ventricular dysrhythmia, or cardiac arrest). Potential predictors of ACVE included previously derived predictors in the overall drug overdose population (prior cardiac disease, initial serum bicarbonate < 20 mEq/L, and initial QTc ≥ 500 ms), exposure circumstances, and initial serum lactate value. Candidate predictors were evaluated using univariate analysis and multivariable regression modeling. Receiver operator characteristic curves were used to derive optimal cutoff points for novel predictors, and prognostic test characteristics were calculated.

RESULTS

Of 355 patients analyzed, ACVE occurred in 34 (9.6%) patients. Initial serum bicarbonate < 20 mEq/L (adjusted odds ratio [aOR] 4.42, 95% confidence interval [CI] 1.94-10.0) and initial QTc ≥ 500 ms (aOR 2.52, 95% CI 1.01-6.09) independently predicted ACVE. Exposure circumstances did not predict ACVE. Initial serum lactate > 5.2 mmol/L independently predicted ACVE (aOR 12.2, 95% CI 2.50-75.2) and was 90.7% specific with 80.3% negative predictive value.

CONCLUSIONS

Metabolic acidosis and QTc prolongation were validated as predictors of ACVE in ED patients with bupropion overdose. Serum lactate elevation was strongly predictive of ACVE in this study and warrants further investigation.

Use of Multimodal Mechanical Support in Refractory Cardiogenic Shock From Bupropion Overdose

Massive bupropion overdose has a known association with cardiogenic shock. We describe a clinical case of a 48-year-old female who was brought to the hospital by emergency medical services after ingesting numerous psychiatric medications. Her hospital course was complicated by worsening cardiogenic shock and ventricular tachycardia storm. Transthoracic echocardiography showed left ventricular (LV) hypokinesis with an ejection fraction of 9%. Then the patient underwent placement of a percutaneous Impella CP device (Abiomed, Danvers, MA). The Molecular Adsorbent Recirculating System was started for protein-bound bupropion clearance. After 24 hours, the patient returned to an organized sinus rhythm. A repeat echocardiogram done on the next day demonstrated improved LV function, and the patient had profound clinical improvement. The case illustrates how the use of extracorporeal membrane oxygenation in combination with Impella device and Molecular Adsorbent Recirculating System was able to support the patient's recovery.

Choosing among second-generation antidepressant treatments for depressed patients with cardiac diseases

Objectives: The present paper aimed to assist physicians in the accurate choice among second-generation agents (SGAs) for patients with cardiovascular disease (CVD). Methods: We reviewed the published pharmacokinetic (PK) and pharmacodynamic (PD) clinical data that report potential -or absence of- drug interactions between second-generation agents (SGAs) and CVD drugs most commonly used in cardiology, including antiplatelet drugs and anticoagulants, statins, beta-blockers, angiotensin-converting enzyme inhibitors, calcium channel blockers, diuretics and the antiarrhythmic drugs amiodarone and digoxin. We also reviewed the cardiovascular safety profile that has been published for each class of SGAs and side effects reported by patients with CVD. Results: Most relevant PK/PD data about SGAs and CVD drugs are based on small studies or detailed case reports. In many cases, the drug interactions are at most assessed in healthy volunteers so that the clinical relevance of findings needs further investigation in patients with CVD. Case reports of serious, sometimes fatal reactions due to concomitant administration of certain drugs require careful consideration. The major cardiac side effects of SGAs include HR increase, postural hypotension and slight prolongation of the intraventricular conduction time and QT interval. On normal dosage of antidepressants, both advanced heart block and ventricular arrhythmias could occur in patients with severe heart disease, together with clinically important loss of myocardial contractile force. Conclusions: Data reported in the present review should help physicians about their decision-making processes that govern SGAs use in CVD patients.