Abstract TP051: DOAC Pharmacologic Interactions in Acute Ischemic/TIA vs Hemorrhagic Stroke: Findings from a 77-Hospital Telestroke Program

Background: Direct oral anticoagulants (DOACs) are central to secondary stroke prevention, yet real-world exposure to drug–drug interactions (DDIs) that alter DOAC exposure or bleeding risk remains under-characterized in acute cerebrovascular care. We assessed cerebrovascular presentations of DOAC users and the prevalence and profiles of clinically relevant DDIs in a nationwide network. Methods: Retrospective study in a Brazilian teleneurology network covering 77 hospitals (calendar years 2022–2025 ), encompassing 38,765 encounters for diverse neurological complaints. A rule-based, typo-tolerant dictionary (generic/brand names) flagged potential DDIs, grouped as pharmacokinetic (PK) inhibitors (↑ DOAC exposure), PK inducers (↓ exposure), and pharmacodynamic (PD) bleeding-risk combinations (antiplatelets, NSAIDs, heparins). Results: Analyses focused on patients with a specified DOAC agent and cerebrovascular subtype ( n=446 ). DOAC distribution: rivaroxaban 314/446 (70.4%) , apixaban 101/446 (22.6%) , edoxaban 17/446 (3.8%) , dabigatran 14/446 (3.1%) . Cerebrovascular presentations: ischemic stroke 381/446 (85.4%) , non-SAH hemorrhagic stroke 41/446 (9.2%) , SAH 18/446 (4.0%) , TIA 6/446 (1.3%) . Interaction prevalence by event group (pre-specified comparison of ischemic/TIA vs hemorrhagic : Ischemic/TIA (n=387): – PD (bleeding-risk): 130/387 (33.6%) – PK inhibitors (↑ exposure): 37/387 (9.6%) – PK inducers (↓ exposure): 18/387 (4.7%) Hemorrhagic (n=59): – PD (bleeding-risk): 15/59 (25.4%) – PK inhibitors (↑ exposure): 7/59 (11.9%) – PK inducers (↓ exposure): 6/59 (10.2%) PD combinations consistently exceeded PK DDIs overall, driven primarily by acetylsalicylic acid/aspirin and clopidogrel ; heparins were less frequent. Among PK interactions, amiodarone predominated as an inhibitor and phenytoin as an inducer. The relative excess of PD DDIs in ischemic/TIA and the higher proportions of PK interactions in hemorrhagic presentations suggest distinct pharmacologic vulnerability profiles relevant to acute management. Conclusions: In this multicenter teleneurology cohort, clinically meaningful DDIs among DOAC users were common, especially bleeding-risk PD combinations (~1 in 3 in ischemic/TIA) and notable PK modifiers in hemorrhagic presentations (≈12% inhibitors; ≈10% inducers). Embedding structured medication reconciliation and automated DDI screening into telestroke workflows—prioritizing antiplatelets, amiodarone , and enzyme-inducing antiepileptics—may mitigate preventable harm.