HEART FAILURE
Clinical Overview

Pharmacotherapy

 

  • Effective agents for heart failure symptoms
  • Effects on survival and progression unknown
  • May be started before, with or after ACE inhibitors
  • Indicated with signs and symptoms of volume overload

Heart failure patients with signs and symptoms of significant volume overload should be immediately started on a diuretic.1 Diuretics are very effective in relieving the signs and symptoms of volume overload in heart failure, but their effects on survival and disease progression are not known. Diuretic therapy can be started before, with, or after ACE inhibitors.


Indications

Thiazides => mild heart failure

Loop diuretics => more severe symptoms

Intravenous therapy => marked volume overload


Patients with mild volume overload can be managed adequately on thiazide diuretics.1 If a patient has severe fluid overload, renal insufficiency (estimated CrCL < 30 mL/min), or persistent edema despite use of thiazides, a loop diuretic should be used instead. Patients with pulmonary edema or marked volume overload should be given intravenous therapy with loop diuretics to obtain brisk diuresis. It is important to avoid overdiuresis, especially before start of ACE inhibitor therapy because this may lead to hypotension and renal insufficiency. ACE inhibitors may facilitate diuresis in some patients.

Monitoring electrolyte disturbances

  • potassium
  • magnesium
  • calcium


Because electrolyte disturbances are common with diuretics, proper monitoring is essential. Potassium (K+ ) depletion can occur with chronic diuretic treatment and levels should be checked every 3 days until stable during initiation, titration, or modification of therapy. ACE inhibitors increase serum K+ levels so many patients treated with both agents may not develop K+ depletion. Because serum K+ can be an unreliable indicator of total body K+ stores, serum K+ levels should be maintained above 4.0 mEq/L. If levels fall below this, K+ supplementation with an oral agent or diet, or K+ sparing diuretic should be initiated. Diuretics can also cause magnesium depletion, which usually accompanies K+ depletion and should be carefully monitored. Calcium levels should also be periodically monitored as hypocalcemia may be indicative of magnesium depletion.

Diuretics: Dosing

Agent

Initial Maximum dose (mg)

Major Adverse Reactions

Thiazide

Hydrochlorothiazide

12.5 - 50 QD

Postural hyotension; increased glucose; uric acid; decreased K+

Chlorthalidone

12.5 - 25 QD

Loop

Furosemide

10 - 40 QD to 240 BID

Same

Bumetanide

0.5 - 1 to 10 QD

Torsemide

5 - 10 QD - 100 QD

Thiazide-related

Metolazone

2.5 - 10 QD

Same

Indapamide

1.25 - 5 QD

Potassium Sparing

Spironolactone

25 QD - 100 BID

Increased K+ (especially w/ ACE inhibitor), rash, gynecomastia (spironolactone only)

Triamterene

50 QD - 100 QD

Amiloride

5 QD or QOD - 20 QD

This table adapted from AHCPR heart failure guidelines and the Geriatric Dosage Handbook, lists selected diuretics used in the treatment of heart failure and hypertension. The dosage for each agent is the recommended range for geriatric patients.1,4 

Proper dosing depends on patient size, age, renal function, dietary sodium intake, and severity of edema.1 Most common adverse effects are postural hypotension, hypokalemia, hyperglycemia, hyperuricemia, and rash. Hyperkalemia can occur with K+ sparing diuretics.

Clinical Trials

The RALES study (Randomized Aldactone Evaluation Study)5 was designed to examine the effect of adding spironolactone to an established drug therapy regimen for heart failure. Since even high doses of ACE inhibitors may not be able to completely suppress the renin-angiotensin-aldosterone system, the addition of the spironolactone further suppressed the system by blocking aldosterone, The study was concluded 18 months early, in June 1998, because the results were so clinically significant that it was considered unethical to continue. The trial included 1663 patients with NYHA Class III or IV heart failure, who were followed for a mean of 24 months. The patients that were randomized to receive the spironolactone therapy showed a 27% decrease in mortality as compared to those patients receiving placebo.

© 1999 Geriatric Consultant Resources LLC.

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