Diuretics in congestive heart failure

Diuretics (see Table 1.1 for a physiological classification) remain an important part of the medical therapy for patients with congestive heart failure (CHF). They control fluid retention and rapidly relieve the congestive symptoms of heart failure (HF). The American College of Cardiology/American Heart Association assigned them a class I indication in patients with symptomatic heart failure who have evidence of fluid retention [1]. Indeed, diuretics are the only drugs used in the treatment of HF that control fluid retention and that rapidly produce symptomatic benefits in patients with pulmonary and/or peripheral edema. Because diuretics alone are unable to effect clinical stability in patients with HF, they should always be used in combination with an angiotensin converting enzyme (ACE) inhibitor and a β-blocker. Despite the widespread use of diuretics, there have yet to be large randomized clinical trials that evaluate their effects on mortality or morbidity (with the exception of aldosterone antagonists, which will be considered separately). Furthermore, care must be exercised in the use of diuretics as both hypovolemia secondary to over-diuresis and hypervolemia secondary to under-diuresis have profound effects on cardiac pathophysiology. Therefore, questions remain about appropriate diuretic use [2]. This chapter will explore the effects, pharmacokinetics, and clinical utility of diuretics in patients with congestive heart failure. Vascular effects of diuretics