विवरण

Valproic acid displaces phenytoin from protein binding and inhibits its metabolism, leading to increased free phenytoin levels despite total levels that may appear unchanged or decreased.

तंत्र

Valproate displaces phenytoin from albumin (protein binding competition) and inhibits its CYP2C9-mediated metabolism; free phenytoin fraction increases.

नैदानिक महत्व

Standard total phenytoin levels may be misleadingly normal while free levels are toxic; nystagmus, ataxia, and mental status changes may develop.

प्रबंधन

Monitor free (unbound) phenytoin levels rather than total levels; watch for phenytoin toxicity signs and adjust dose accordingly.

चिकित्सा अस्वीकरण

This content is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making medication decisions.

Data sources: ChEMBL, PubChem, DailyMed.