Diuretic Therapy
One of the aims of treatment of congestive heart failure is directed toward controlling salt and water retention (central or peripheral edema). Diuretics provide effective relief of symptoms in patients with moderate to severe congestive heart failure. Though excessive diuresis can lead to electrolyte imbalance and neuro-humoral activation, most of the symptomatic patients require some diuretics for symptom relief. Daily weight measurement is an important guide to the adequacy of this therapy.
Thiazide Diuretics and Similar Agents
When fluid retention is mild, a thiazide diuretics or a similar type of agent may be sufficient (hydrochlorothiazide, 25-100 mg; metolazone, 2.5-5 mg; chlorthalidone, 25-50 mg; etc).
Thiazide agents are generally ineffective when the glomerular filtration rate falls below 30-40 mL/min. Metolazone maintains its efficacy down to a glomerular filtration rate of approximately 20-30 mL/min.
Adverse reactions: Hypokalemia, prerenal azotemia, skin rashes, neutropenia and thrombocytopenia, hyperglycemia, hyperuricemia, and hepatic dysfunction.
Loop Diuretics
Patients with more severe heart failure should be treated with one of the loop diuretics. These agents are active even in severe renal insufficiency.
E.g. Furosemide (20-320 mg daily),