LAUSR

TOPIC: Cardiovascular Disease TYPE: Medical Student/Resident Case Reports INTRODUCTION: Azithromycin (AZ) is extensively used, with millions of prescriptions written yearly. In 2013 US food and drug administration issued a warning against the pro-arrhythmogenic activity of this drug in the presence of pre-existing cardiac conditions, known QT prolongation or QT-prolonging drug use and electrolyte abnormalities.(1) A recent study collected data on over 12 million patients showing the risk of cardiac events with AZ was rare ~0.03%, and there was no increased risk when compared to amoxicillin.(1,2) Here we report a patient with no known cardiac comorbidities who developed torsades des pointes (TdP) after 2 days of initiating AZ. CASE PRESENTATION: A 77-year-old African American female with a history of acid reflux, type 2 diabetes mellitus, hypertension, hypothyroidism, presented to the emergency room with dyspnea and dry cough for one day. On arrival, patient had a temperature of 99.5F, pulse 115 beats/min, respirations at 32 breaths/min, blood pressure 120/66 and saturating in the 80s on room air, with an unremarkable physical exam. She had leukocytosis at 12.8k, d-dimer 2.15. Computed tomography with angiography ruled out pulmonary embolism but showed bibasilar opacities. She had normal sinus rhythm with a QTc of 393 on ECG at presentation. COVID test was negative;She was empirically treated for community-acquired pneumonia with IV ceftriaxone and IV AZ, with which patient had significant clinical improvement and oxygen requirement. However on day 2 of hospitalization, she developed an episode of generalized tonic-clonic seizure followed by a cardiac arrest secondary to TdP with successful resuscitation in 15 minutes. Magnesium was 1.9, potassium 3.8. In the absence of risk factors like, cardiac disease, arrhythmias, concomitant use of QT prolonging drugs, and significant electrolyte abnormality, this event was attributed to the use of azithromycin. Naranjo adverse drug reaction scale score was 6. While in the ICU, patient was managed with amiodarone, metoprolol, AZ was discontinued. She made marked recovery and was extubated within 3 days, transferred to the floor where no further arrhythmias were noted. She was subsequently discharged to rehab on a short course of amoxicillin-clavulanate, amiodarone, metoprolol, and close cardiology follow-up. DISCUSSION: AZ is a relatively safe drug compared to other macrolides, and reports of cardiac arrhythmias induced solely by this drug with no concomitant risk factors are extremely rare. The evidence from meta-analyses and systematic reviews on the association of AZ with cardiac events are conflicting (3), and further investigations are warranted to assess this association. CONCLUSIONS: This case serves to reiterate the association of potentially fatal arrhythmias induced by a commonly prescribed antibiotic. Although these events are rare, they should be on our radar in clinical practice. REFERENCE #1: Patel H, Calip GS, DiDomenico RJ, Schumock GT, Suda KJ, Lee TA. Comparison of Cardiac Events Associated With Azithromycin vs Amoxicillin. JAMA Network Open. 2020;3(9):e2016864-e2016864. REFERENCE #2: Patel H, DiDomenico RJ, Suda KJ, Schumock GT, Calip GS, Lee TA. Risk of cardiac events with azithromycin-A prediction model. PLoS One. 2020;15(10):e0240379. REFERENCE #3: Almalki ZS, Guo JJ. Cardiovascular events and safety outcomes associated with azithromycin therapy: a meta-analysis of randomized controlled trials. Am Health Drug Benefits. 2014;7(6):318-328. DISCLOSURES: No relevant relationships by Khushdeep Chahal, source=Web Response No relevant relationships by Sangeetha Isaac, source=Web Response No relevant relationships by Sucheta Kundu, source=Web Response No relevant relationships by Ishita Mehra, source=Web Response