Drug Interaction Report

MONITOR: The concomitant use of recombinant interferon-alpha-2a and some angiotensin converting enzyme (ACE) inhibitors has been associated with a higher incidence of granulocytopenia than either drug used alone in patients with cryoglobulinemia. The mechanism is unknown but may be related to an autoimmune response. It is also unknown whether patients with other conditions may be affected. Data exist for enalapril and captopril.

MANAGEMENT: Until more information is available, close hematologic monitoring is recommended.

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.