Question

why would diuretics be perscribed for long term use?

Answer 1

Diuretic use is crucial in the management of symptomatic heart failure with pulmonary or systemic congestion, or both. There were few other choices. Long-term diuretic use with thiazides ,loop diuretics, such as furosemide (Lasix), became the diuretics of choice for patients with heart failure and fluid retention. There is little doubt that these potent diuretics have eased the management of this condition, and most patients can now be kept reasonably free of severe edema and pulmonary congestion. For most patients with advanced heart failure, there is no alternative to the use of potent diuretics to manage the symptoms that have the greatest effect on quality of life.

With the more recent awareness of the critical importance of the neurohormonal aspects of heart failure, we now recognize that diuretics may have deleterious effects on the heart itself. Blood volume contraction, via diuretics or otherwise, stimulates the renin-angiotensin-aldosterone system (RAAS), which in turn stimulates the sympathetic nervous system, resulting in progression in the structural and functional disorder that characterizes heart failure.

most of these patients were taking angiotensin-converting enzyme (ACE) inhibitors, which would be expected to ameliorate at least some of the adverse effects of RAAS stimulation by diuretics. Most were not taking beta blockers, which had not yet become standard treatment for heart failure when the DIG trial was undertaken. Nor were they taking aldosterone inhibitors, which have since become widely used for severe heart failure and for heart failure occurring with acute myocardial infarction.

Diuretic use on a daily basis should be reserved for those patients who truly need it. It is better to individualize diuretic dosage, especially for those patients who may retain fluid only occasionally. Indeed, weight-based administration of diuretics is a successful strategy in many patients with class I or class II heart failure. Even the more severely symptomatic patient can use dose adjustment based on weight to avoid the daily use of the most potent regimen. In addition, it would appear likely that the worst effects of neurohormonal stimulation by diuretics can be antagonized by use of ACE inhibitors or angiotensin receptor blockers, or both; beta blockers; and at least in selected cases, aldosterone antagonists.