Safe administration of temozolomide in end-stage renal disease patients.

INTRODUCTION
Glioblastoma multiforme is the most common and aggressive type of central nervous system tumor. We present a novel case of the challenges of dosing temozolomide in a patient with end stage renal disease on peritoneal hemodialysis with unpredictable clearance and toxicities.


CASE REPORT
In this case, a 60-year-old male with a past medical history of hypertension and Stage V chronic kidney disease presented with worsening confusion and word-finding difficulty in the emergency department. Magnetic resonance imaging demonstrated a large intra-axial mass within the posterior left frontal lobe measuring 4.5 × 4.1 × 3.5 cm with irregularly, predominant peripheral tumoral enhancement.


MANAGEMENT AND OUTCOME
The patient underwent a surgical resection which confirmed the diagnosis of glioblastoma (grade 4). The standard treatment for glioblastoma is 6 weeks of radiation therapy and daily temozolomide. Given his history of renal dysfunction and limited data on the safety of temozolomide in patients on hemodialysis (HD), the patient was administered dose-reduced temozolomide and closely monitored for toxicities. Temozolomide was successfully up-titrated to the full dose.


DISCUSSION
Renal replacement therapy is a life-saving treatment for end-stage kidney disease patients. A stepwise increase in the dosage of temozolomide did not increase the risk of toxicity with HD. There are no studies with patients on temozolomide and peritoneal dialysis. Our case transitioned to peritoneal dialysis from HD without significant toxicity from temozolomide. As a more substantial proportion of the population becomes dialysis-dependent in the coming years, we need further studies to understand the safety profiles of chemotherapeutic agents in this complex subset of patients.