ModerateAntiplatelet agents (low dose) / NSAIDs (analgesic dose)×Antiepileptics. Fatty acid derivatives
Updated · Methodology
Mechanism
Aspirin displaces valproate from albumin binding and suppresses its metabolism. The free valproate fraction rises, raising neurotoxicity risk (tremor, sedation, hyperammonaemia).
Symptoms
Tremor, drowsiness, nausea, confusion. Severe cases: hyperammonaemic encephalopathy. Symptoms appear within 1–2 weeks at high aspirin doses.
Management
Cardioprotective aspirin doses (75–100 mg) are usually acceptable. At high doses, check valproate level at 1 week. For chronic analgesia on valproate: paracetamol.
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.
Summary of a multi-drug list →
Medicine list: everything you take in one place →
Sources
- FDA: Warfarin sodium tablet (Amneal Pharmaceuticals LLC) – Prescribing Information (2017)– ; DailyMed setid 558b7a0d-5490-4c1b-802e-3ab3f1efe760
- AEMPS: Ficha técnica: Ácido acetilsalicílico (nº registro 76237), sección 4.5 (2026)– AEMPS, CIMA, nº registro 76237, revisión 08/2026, sección 4.5