Oncology Pharmacy Consults
Lysis Crisis:
Pharmacist's Role and Responsibility in the Management of Tumor Lysis Syndrome

INTRODUCTION

Tumor lysis syndrome (TLS) is the most common disease-related emergency encountered during the treatment of patients with cancer.1 The incidence of TLS has been increasing in recent years, possibly due to the introduction of more effective and targeted therapies. It is most common in patients with several hematologic cancers, such as acute leukemias, high-grade non-Hodgkin lymphomas, and Burkitt lymphoma, but has been documented in patients with almost all cancer types.

Tumor lysis syndrome is more common among patients with bulky, rapidly proliferating, treatment-responsive tumors and is a result from the rapid release of cellular contents from dying cancer cells.2 Purine nucleosides are metabolized to uric acid that builds up to high levels in the blood. In the kidney, particularly the distal tubules, urate crystals are deposited, blocking urine production, and leading to acute kidney injury. Increased mortality is associated with renal dysfunction.3

In addition to uric acid build up, potassium and phosphate are liberated in large quantities from dying cells.2 Hyperkalemia and hyperphosphatemia, with secondary hypocalcemia, pose increased risks for life-threatening cardiac dysrhythmias, seizures, renal insufficiency, and muscle dysfunction.

Patients' fluid management is the cornerstone of TLS prophylaxis and treatment. Allopurinol and rasburicase are antihyperuricemic agents with utility for managing patients with TLS. Allopurinol lowers uric acid levels by blocking the metabolism of purines to uric acid and is used for prophylaxis of TLS. Rasburicase is a recombinant urate oxidase that rapidly lowers uric acid levels and may be used for prophylaxis in patients at high risk for TLS or for the treatment of hyperuricemia in patients with established TLS.2-3

As the medication experts in a care team, pharmacists play a key role in recommending dose reductions, monitoring adverse events and drug-drug interactions, and educating patients on the proper use of medications. This activity provides pharmacists with a review of the epidemiology, pathophysiology, and strategies for the prevention and treatment of TLS in patients with cancer.


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