Lowering of furosemide dosage after clinical stabilization in patients with congestive heart failure

This study was performed to examine the safety of reducing the long-term doses of furosemide administered to patients with congestive heart failure (CHF) stabilized on a standard medical treatment.

Twenty-nine patients with advanced CHF were treated with enalapril, digoxin, nitrates, and furosemide, as needed to alleviate their symptoms, and remained clinically stable for at least 3 months on those doses. Subsequently, the daily dose of furosemide was reduced to 1/3 of the previous dose, while the concomitant therapy was unchanged. All patients underwent a thorough clinical evaluation and right-heart catheterization before and 2 months after the furosemide dose reduction. After the treatment optimization the NYHA functional class decreased from 2.3 +/- 0.6 to 1.4 +/- 0.6 (p = 0.000), and the left ventricular ejection fraction increased from 22 +/- 10% to 32 +/- 13%, (p = 0.000). Clinical and haemodynamic evaluation before and after 2 months of treatment with lower furosemide doses showed that 24 of the 29 patients (83%) remained in a stable NYHA functional class and maintained a stable haemodynamic status. In the remaining 5 patients (17%), mean NYHA functional class increased from 1.8 +/- 0.4 to 2.4 +/- 0.6 (p = 0.07), accompanied by a significant increase of the right and left ventricular filling pressures from 4.2 +/- 2.7 to 9.0 +/- 3.0 mm Hg, p = 0.018 and from 8.6 +/- 3.0 to 19.8 +/- 3.6 mm Hg, p = 0.017, respectively. These 5 patients returned to a stable clinical status upon resumption of the prior doses of furosemide.

Most patients with chronic CHF who were clinically stabilized on high doses of furosemide remained stable on a maintenance dose equal to one-third of the dose needed for their stabilization. Patients unable to tolerate the dose reduction regained their previous clinical status following the resumption of the prior diuretic doses.