Introduction: 5-Fluorouracil is an antineoplastic agent generally used to treat various types of solid tumors. The common adverse drug reaction associated with 5-fluorouracil are myelosuppression, mucositis, diarrhea, and hand-foot syndrome. Neurological side effects such as headache, dizziness, convulsion, encephalopathy, and acute cerebellar syndrome are rare in nature.

Case presentation: We report a case of 5-fluorouracil induced cerebrovascular accident (CVA) in a patient with no risk factors for CVA before chemotherapy. A 37 years old female patient diagnosed with carcinoma rectum underwent six cycles of chemotherapy with 5- fluorouracil- calcium leucovorin- irinotecan (FOLFIRI regimen). After completing the last cycle, she developed headache, vomiting, and facial deviation along with high blood pressure (260/160 mmHg). MRI brain was done, and it revealed acute non-hemorrhagic lacunar infarct in the left half of pons. 5-fluorouracil induced CVA was suspected and was managed with dual antiplatelet, statin, and antihypertensives.

Conclusion: The clinicians and clinical pharmacists must be aware about the potential of 5-FU to induce rare side effects such as CVA even in low risk patients in order to avoid permanent harm to the patient.

Keywords: 5-fluorouracil; antineoplastic agent; cerebrovascular accident.