Severe Cardiotoxicity Associated with Ixabepilone Use in Metastatic Breast Cancer

OBJECTIVE: To report a case of cardiogenic shock and fulminant heart failure associated with a single dose of ixabepilone. CASE SUMMARY: A 32-year-old woman presented to the emergency department (ED) with abdominal pain and difficulty breathing within 1 hour after receiving a partial dose of ixabepilone (26 mg/m(2)) at an oncologist's office. She had breast cancer, with metastases to the bone and liver and evidence of early liver failure. While in the ED, she developed acute respiratory failure requiring intubation. Bedside ultrasound imaging showed free abdominal fluid. Computed tomography (CT) scans showed evidence of right-sided heart failure and abdominal fluid consistent with ascites but no evidence of pulmonary embolism. After the CT scan, the patient experienced pulseless electrical activity cardiac arrest. All attempts at resuscitation were unsuccessful. DISCUSSION: Ixabepilone is a novel drug for treatment of advanced breast cancer. The most commonly reported adverse effects are peripheral neuropathies and hematologic issues such as neutropenia. To our knowledge, this is the first detailed report of a severe adverse cardiac event associated with ixabepilone use. Many other chemotherapeutic agents have cardiotoxic effects. An objective causality assessment, using the Naranjo probability scale, revealed that an adverse drug event was probable. CONCLUSIONS: Clinicians should maintain broad differential diagnoses that include adverse reactions to drugs relatively new to the market. Ixabepilone may have cardiotoxic effects that necessitate further study, particularly when the drug is administered after cardiotoxic chemotherapy.