Amlodipine × Dexamethasone

Dexamethasone is a weak CYP3A4 inducer. With prolonged therapy, amlodipine plasma levels may modestly fall and the antihypertensive effect weaken.

Gradual blood pressure rise 2–4 weeks after starting the glucocorticoid. In heart failure: oedema, weight gain.

For short dexamethasone courses (up to 7 days), no adjustment. For prolonged systemic therapy, monitor blood pressure every 2 weeks; increase amlodipine if needed.