Irinotecan (Camptosar©, CPT-11), a topoisomerase I inhibitor, is a commonly used cytotoxic chemotherapeutic in the treatment of multiple malignancies, particularly of gastrointestinal origin. Dysarthria secondary to irinotecan has been described as a rare side effect in a few case reports with limited data to recommend appropriate management. We describe herein a large single institution experience of patients with gastrointestinal malignancies who experienced dysarthria while being treated with irinotecan-based chemotherapy regimens (FOLFIRINOX or FOLFIRI+/-bevacizumab). Eighteen patients developed neurological manifestations during irinotecan infusion with the majority ( n = 17) developing dysarthria. Patients also experienced other known side effects including cholinergic effects (abdominal bloating, diarrhea, facial flushing, diaphoresis, and rhinorrhea), nausea, fatigue, perioral paresthesia and musculoskeletal discomfort. The dysarthria occurred as early as with the first infusion of irinotecan ( n = 9), but several patients did not develop symptoms until subsequent infusions (range, 1-6). Dose alterations of irinotecan did not obviously impact the reccurrence or severity of dysarthria. Management strategies included close observation, atropine, slower irinotecan infusion rate, and reassurance. Dysarthria resolved without consequence in all patients within hours of completion of the infusion. Oncologists and pharmacists should be aware of irinotecan-associated dysarthria as a rare, self-limited phenomenon with no long-term sequelae, and appropriately counsel patients and infusion nurses to avoid inadvertently withholding potentially beneficial therapy for patients with gastrointestinal malignancies.
Keywords: CPT-11; Camptosar; Irinotecan; dysarthria.