A nurse is reviewing a patient's medications prior to administration. Which drug-to-drug interactions should most concern the nurse in a patient with a history of heart failure and a potas-sium level of 5.5 mEq/L?

Question

a. Furosemide (Lasix) and enalapril (Vasotec)
b. Amlodipine (Norvasc) and spironolactone (Aldactone)
c. Eplerenone (Inspra) and spironolactone (Aldactone)
d. Metoprolol (Lopressor) and furosemide (Lasix)

Answer 1

C
The greatest risk with eplerenone is hyperkalemia, and combining this drug with a potas-sium-sparing diuretic creates a significant risk of hyperkalemia.
Furosemide and enalapril, an ACE inhibitor, would not be contraindicated in this patient.
Amlodipine and spironolactone would not cause hyperkalemia.
The combination of metoprolol, a beta blocker, and furosemide would not be contraindicated in this patient.