Identify medications that may be helping to induce this arrhythmia

Question

A 60-year-old woman presents to the emergency room complaining of syncope. She was in her car when she had the episode and had a minor accident. She indicates that she has had more than one syncope event in the past three days. She has been showing symptoms of respiratory tract infection and COVID-19 is suspected and a doctor prescribed hydroxychloroquine with azithromycin 4 days ago. His past medical history includes hypertension, depression and ventricular arrhythmias for which he uses hydrochlorothiazide, dialthiazem, sertraline and mexiletine. In the emergency room an EKG is done and is diagnosed with Torsades de Pointes tachycardia.

Identify medications that may be helping to induce this arrhythmia

Answer 1

Hydroxychloroquine can increase the QT interval, leading to torsade. The timing of the syncope episodes, beginning one day after this was prescribed, suggest hydroychloroquine as the proximate cause.

Answer 2

Hydrochlorothiazide (HCTZ) is a diuretic that is often prescribed to treat hypertension, edema, and heart failure. Diuretics can leads to TdP due to the increased excretion of potassium and magnesium. These deficiencies can lead to prolonged QT intervals which in turn can lead to TdP.

Derick G. Miranda, P. D. C. U. M. K. C. S. of P. C. L. M. M. (2011, February 18). Medication-Induced QT-Interval Prolongation and Torsades de Pointes. U.S. Pharmacist – The Leading Journal in Pharmacy. https://www.uspharmacist.com/article/medication-induced-qt-interval-prolongation-and-torsades-de-pointes.

Romero, J., Baldinger, S. H., Goodman-Meza, D., Engstrom, K., Valencia, C. R., Golive, A., … Ferrick, K. J. (2015). Drug-induced torsades de pointes in an underserved urban population. Methadone: is there therapeutic equipoise? Journal of Interventional Cardiac Electrophysiology, 45(1), 37–45. https://doi.org/10.1007/s10840-015-0077-2