The principal goals of treatment of the patient in
heart failure are the relief of their symptoms and improvement in their prognosis. Of all antiheart failure drugs currently available, the
diuretics are therapeutically superior in their efficacy in relieving clinical symptoms and signs. Whether administered intravenously or orally, all
diuretics result in a substantial reduction in the raised pulmonary vascular pressures in combination with a small reduction in cardiac output.
Diuretics stimulate release of
renin with subsequent activation of the renin-angiotensin-aldosterone system, particularly if used in large doses, although their quantitative impact on the neuroendocrine profile at different stages of
heart failure remains to be defined. In patients with mild
heart failure,
diuretics reduce plasma
catecholamine concentrations, but their
sympatholytic effects in more severe cases are unknown, as are their effects on the metabolically active tissues in these patients.
Diuretic resistance can be circumvented by segmental nephron blockade with a combination of low-dose
diuretics that simultaneously block
sodium reabsorption in the proximal tubule, the loop of Henle, the distal tubule, and the collecting duct.
Diuretics improve symptoms of
breathlessness and signs of peripheral
edema in patients with
congestive heart failure in direct relationship to the induced diuresis. These benefits are frequently associated with a substantial improvement in patients' appreciation of quality of life and economic capacity. There are few adverse reactions to chronic
diuretic therapy, but the serum
electrolytes should be monitored for
hypokalemia and hypomagnesemia. The impact of
diuretics on prognosis of patients with
congestive heart failure is unknown; however,
diuretics have been a major ingredient of the
therapies used in all the survival trials with
vasodilators,
angiotensin-converting enzyme inhibitors, and beta-blocking drugs. In addition to their clinical benefits,
diuretics are the most cost-effective treatment of any single
drug group currently available for the treatment of patients with
congestive heart failure.