Inspra and Renal dysfunction

The use of eplerenone is contraindicated in patients with renal impairment as defined by serum creatinine above 2.0 mg/dL for males or 1.8 mg/dL for females, or a creatinine clearance (CrCl) below 50 mL/min. These patients are at increased risk of developing persistent hyperkalemia, which is the principal adverse effect of eplerenone and can lead to potentially life-threatening cardiac arrhythmias. The incidence of hyperkalemia increases with decreasing renal function. In clinical studies of eplerenone, serum potassium levels exceeding 5.5 mEq/L were observed in 10.4% of treated patients with baseline calculated CrCl less than 70 mL/min, 5.6% of patients with baseline CrCl 70 to 100 mL/min, and 2.6% of patients with baseline CrCl greater than 100 mL/min. Careful monitoring of serum potassium levels is necessary in patients treated with eplerenone who are at risk for the development of hyperkalemia, especially during initiation of therapy, after dosage adjustment, and during illness that could alter renal function. In clinical trials, monitoring occurred every 2 weeks for the first 1 to 2 months, then monthly thereafter. Eplerenone should be withdrawn immediately if hyperkalemia develops, and measures should be initiated to lower serum potassium if it exceeds 6.5 mEq/L.