Abstract Details Title A Rare Case of Profound Tirofiban-induced Thrombocytopenia in Ischemic Stroke Topic Cerebrovascular Disease and Interventional Neurology Presentation(s) P1 - Poster Session 1 (8:00 AM-9:00 AM) Poster/Presentation Number 5-021 Objective We aim to highlight a rare but serious side effect of a commonly used medication in ischemic stroke. It is important to study reported cases to elucidate etiologies and risk factors in an already compromised patient population. Background Thrombocytopenia is well-documented side effect of antiplatelet medications. In tirofiban, studies show an overall 1-5% risk of thrombocytopenia. Profound thrombocytopenia (<20x109/L) is extremely rare, with only one other case reported in the literature. The proposed mechanism is an auto-immune mediated reaction following exposure. Given the paucity of cases, little is known regarding risk factors or best management. Design/Methods NA Results A 58-year-old female presented with sudden onset left hemiparesis, facial droop, and dysphagia. Neuroimaging demonstrated occlusion of the left vertebral and basilar arteries. As there were no contraindications, she received acute treatment for ischemic stroke: Tenecteplase and mechanical thrombectomy with stent placement. Post-procedure, she was on tirofiban which was transitioned to aspirin and clopidogrel for stent patency. Her hospital course was complicated, she eventually required tracheostomy and gastric tube placement. As part of procedural planning, clopidogrel was transitioned back to tirofiban. The following day, she experienced profound acute thrombocytopenia (<1x109/L). There was no site of active bleed and thrombocytopenia gradually improved with platelet transfusions and steroid treatment. Unfortunately, the patient had a poor outcome due to other comorbidities and she was discharged to hospice. Conclusions Profound thrombocytopenia following tirofiban administration remains a rare but significant complication in ischemic stroke management. Remarkably, the deficiency manifested after subsequent treatment. The immune-mediated pathogenesis has been described but remains incompletely understood.While tirofiban has demonstrated efficacy and a favorable safety profile in acute ischemic stroke, clinicians should remain vigilant for rare but serious adverse events. This case highlights the need for further research to clarify patient-specific risk factors, optimal monitoring strategies, and management protocols for tirofiban-induced thrombocytopenia. Authors/Disclosures Micah Sy, MD PRESENTER Dr. Sy has nothing to disclose.