Experience with Vincristine - Associated Neurotoxicity

OBJECTIVES: To evaluate the frequency and severity of occurrence of vincristine-associated neurotoxicity. DESIGN: A retrospective case series study. SETTING: Hurlingham Oncology Clinic, Nairobi. SUBJECTS: Thirty-eight patients treated for various neoplasms with vincristine containing chemotherapeutic regimens. MAIN OUTCOME MEASURES: The frequency and degree of neurotoxicity when vincristine was given at the standard dose of 1.4 mg/m2. RESULTS: Five patients (13.2%) developed peripheral neuropathy, one having had it even before vincristine was started. Therefore only four (10.5%) had it attributed to vincristine. Four of the patients who developed neuropathy (80%) were HIV-positive. Neuropathy grade 2 (severe) occurred in only two patients leading to discontinuation of the drug. All the neurotoxicity resolved after discontinuation of vincristine. CONCLUSION: Vincristine induced neuropathy occurred but was rarely severe at a dose of 1.4 mg/m2. It appeared to be more frequent in HIV infected individuals, but controlled studies with bigger sample sizes are required to determine whether this may warrant routine capping of the dose at a maximum of 2 mg.