Описание
Ranitidine may slightly increase phenytoin bioavailability through modest inhibition of CYP2C9, though the interaction is less significant than with cimetidine.
Механизм
Ranitidine inhibits CYP2C9 weakly, reducing phenytoin hydroxylation; additionally, raised gastric pH from H2 blockade may alter phenytoin absorption kinetics.
Клиническое значение
Case reports describe phenytoin toxicity (nystagmus, ataxia) with ranitidine; the effect is variable and generally smaller than cimetidine's.
Тактика ведения
Monitor phenytoin levels and watch for signs of toxicity when starting ranitidine; consider switching to a less interacting agent if needed.
Медицинский отказ от ответственности
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.