Case Report: Successful management of acute vincristine overdose in a cat with metastatic gastric lymphoma using therapeutic plasma exchange.

A 10-year-old male castrated Siamese cat with gastric large B-cell lymphoma was presented following an accidental overdose of vincristine, four times the intended dose. The initial management involved administering intravenous lipid emulsion. Extracorporeal therapy was implemented to reduce plasma vincristine concentrations, beginning with therapeutic plasma exchange (TPE) and followed by hemoperfusion (HP). Vincristine clearance was not confirmed through pre- and post-treatment serum levels due to a laboratory handling error. The patient became apneic at the initiation of HP, prompting discontinuation of treatment and completion of TPE alone. Post-TPE management combined intensive supportive care with the administration of cholestyramine, calcium folinate, and granulocyte colony-stimulating factor. The cat survived to discharge, suggesting a potential role for extracorporeal therapy in managing chemotherapeutic toxicity. However, the absence of pre- and post-treatment serum vincristine levels prevents a definitive assessment of therapeutic efficacy.