Do diuretics differ in terms of clinical outcome in congestive heart failure?

Diuretics are required in the majority of patients with symptomatic congestive heart failure (CHF). The reduction of pulmonary venous congestion results in rapid improvement of dyspnoea and increased exercise tolerance. In contrast to arterial hypertension, there are only a few studies comparing diuretics with other drugs in CHF. In particular, no reliable data exist on the effect of diuretics on mortality and major cardiac events in CHF. Diuretic agents differ in their mode of action, pharmacodynamics and pharmacokinetic properties. Loop diuretics are used in acute CHF and in severe chronic CHF, while thiazides, having a longer duration of action, are suitable for long-term therapy of mild CHF in ambulatory patients. Potassium-sparing diuretics are usually prescribed in combination with other preparations to prevent electrolyte disturbances. No randomized prospective large-scale trials have been carried out to compare the efficacy and tolerability of the various types of diuretics. With adequately chosen dosage, the effects of the different loop diuretics appear to be similar in CHF. However, observational data in ambulatory patient populations indicate that loop diuretics with high bioavailability and longer half-life may offer advantages in terms of clinical stability and resource utilization for cardiac decompensation. In patients with severe pulmonary congestion and oedema, combined use of loop diuretics and thiazides may improve the therapeutic response. Spironolactone can also be prescribed to increase diuresis in patients who are resistant to a combination of loop diuretics and ACE inhibitors.