An Acute Atypical Cardiovascular Adverse Reaction to Bortezomib in an Elderly Man with Multiple Myeloma - A Case Report

Introduction: Bortezomib is a proteasome inhibitor used in the treatment of mul-tiple myeloma. It has a well-documented adverse event profile extending over nervous and hematological systems. Herein, we describe the case of a patient who developed an atypical adverse cardiovascular reaction within hours of administering bortezomib. Case Presentation: A 67-year-old male patient was diagnosed with multiple myeloma and was started on a triple regimen comprising bortezomib, lenalidomide, and dexamethasone. The first dose of bortezomib was without any adverse reaction. However, two hours after the second dose of the first cycle, the patient developed supraventricular tachyarrhythmia, tach-ypnea with wheeze, and hypertension, which was followed by a decline in the Glasgow Coma Scale score and resultant intubation. Conclusion: Multiple myeloma patients are at a high risk of cardiovascular events because of the disease itself as well as co-morbidities. Near-immediate-onset supraventricular arrhyth-mias have not been reported previously with the use of bortezomib. The rapidity of onset of cardiac, respiratory, and nervous system disturbances in our patient also suggests the possi-bility of an immunogenic reaction resembling anaphylaxis. The Naranjo score of causality assessment in the current case was 5, indicating a probable association of the acute cardiovas-cular reaction with bortezomib. The underlying pathogenesis of this rare but possibly fatal adverse effect should be explored in the future.