Описание
Diltiazem inhibits CYP3A4-mediated tamsulosin metabolism, increasing tamsulosin plasma concentrations by up to 2-fold and heightening the risk of orthostatic hypotension and dizziness.
Механизм
Tamsulosin is metabolised by CYP3A4 and CYP2D6; diltiazem's CYP3A4 inhibition reduces tamsulosin clearance, increasing its AUC. Additionally, diltiazem has mild vasodilatory properties that may add to tamsulosin's alpha-1 blockade-induced hypotension.
Клиническое значение
Pharmacokinetic studies confirm tamsulosin AUC increases of approximately 2-fold with diltiazem; case reports and spontaneous reports describe orthostatic hypotension and syncope.
Тактика ведения
Use with caution; advise patients on fall precautions and orthostatic hypotension risk; consider reducing tamsulosin dose or monitoring blood pressure when diltiazem is initiated or dose-increased.
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.