Drug Interaction Report

MONITOR: Corticosteroids may antagonize the effects of antihypertensive medications by inducing sodium and fluid retention. These effects may be more common with the natural corticosteroids (cortisone, hydrocortisone) because they have greater mineralocorticoid activity. Conversely, some calcium channel blockers such as diltiazem and verapamil may increase corticosteroid plasma levels and effects by inhibiting their clearance via CYP450 3A4 metabolism.

MANAGEMENT: Patients on prolonged (i.e., longer than about a week) or high-dose corticosteroid therapy should have blood pressure, electrolyte levels, and body weight monitored regularly, and be observed for the development of edema and congestive heart failure. The dosages of antihypertensive medications may require adjustment.

GENERALLY AVOID: Moderate-to-high dietary intake of potassium can cause hyperkalemia in some patients who are using angiotensin converting enzyme (ACE) inhibitors. In some cases, affected patients were using a potassium-rich salt substitute. ACE inhibitors can promote hyperkalemia through inhibition of the renin-aldosterone-angiotensin (RAA) system.

MANAGEMENT: It is recommended that patients who are taking ACE inhibitors be advised to avoid moderately high or high potassium dietary intake. Particular attention should be paid to the potassium content of salt substitutes.