Irinotecan-Associated Dysarthria in Patients with Pancreatic Cancer: A Single Site Experience

BACKGROUND Irinotecan, a topoisomerase I inhibitor, is a cytotoxic chemotherapeutic agent used to treat multiple malignancies, including those of colorectal, pancreatic, cervical, esophageal, gastric, and lung origin. Dysarthria, a state of difficult or unclear articulation of speech, has been reported as a rare side effect of irinotecan through multiple case reports and case series, but with limited published data aimed at understanding the underlying mechanism and effective management strategies. CASE REPORT We describe herein 3 cases of patients with pancreatic malignancy who experienced dysarthria while being treated with a chemotherapy regimen containing irinotecan at an ambulatory outpatient satellite chemotherapy site. All patients described received first-line FOLFIRINOX for pancreatic cancer and experienced dysarthria during their first infusion of irinotecan. In all cases, dysarthria was observed as a transient adverse drug reaction within the first 10 to 70 min of irinotecan infusion, which resolved rapidly upon pausing infusion without any long-term sequalae. All patients remained conscious and alert; physical and neurological examinations at dysarthria onset revealed no abnormalities. Some patients experienced distal extremity paresthesia, a known manifestation of oxaliplatin-induced acute neurotoxicity, and diaphoresis and nausea. Increased infusion time effectively prevented dysarthria during subsequent infusions. CONCLUSIONS Oncologists, pharmacists, nurses, and other care team members should be aware that irinotecan-associated dysarthria is a rare, mild, and self-limiting phenomenon to avoid inadvertently altering or withholding therapy. We suggest extending irinotecan infusion time, as opposed to dose reduction or treatment discontinuation, as a practical clinical management strategy for patients who develop recurrent dysarthria secondary to irinotecan infusion.