Diuretics
Diuretic drugs, also known as water pills, are commonly prescribed to treat high blood pressure, edema, and congestive heart failure. All diuretic drugs which are usually called diuretics cause a person to "lose water". Diuretics work by different mechanisms, most commonly in following ways:
- By inhibiting the ability of kidney to reabsorb sodium, thus enhancing the loss of sodium in the urine. When sodium is lost in the urine, water goes with it. Diuretic which inhibits reabsorbtion of sodium is called a high-ceiling diuretic or a loop diuretic.
- By increasing the excretion of both sodium and chloride in the urine so that water is excreted with them. This is how the thiazide diuretics work.
- By blocking the exchange of sodium for potassium, resulting in excretion of sodium and potassium but relatively little loss of potassium. These diuretics are therefore termed potassium sparing diuretics.
Diuretic drugs are non habit forming. Diuretic drugs stimulate the kidneys to produce more urine, flushing excess fluids and minerals (e.g., sodium) from the body. There are four general types of diuretics: loop, osmotic, potassium-sparing and thiazide (or thiazide-like). It is important to know that none of these diuratics is recommended for pregnant women, and only potassium-sparing diuretics appear to be safe during breast feeding
Therapeutic Uses of Diuretic Drugs
» Hypertension
Hypertensive patients or persons with high blood pressure, of which 90-95% have hypertension of unknown origin (primary or essential hypertension), are effectively treated with diuretics. Antihypertensive therapy with diuretic drugs is particularly effective when coupled with reduced dietary sodium intake.
» Heart Failure
Most patients in heart failure are prescribed a loop diuretic because they are more effective in unloading sodium and water than thiazide diuretics. In mild heart failure, a thiazide diuretic is generally prescribed. Potassium-sparing, aldosterone-blocking diuretics (such as, spironolactone) are being used increasingly in heart failure.
» Pulmonary & Systemic Edema:
Edema is a swelling, usually of the legs, due to the accumulation of excessive fluid in the tissues. Excess fluid that accumulates in the lungs is called pulmonary edema. Therapy for edema consists of treating the underlying conditions, restricting salt intake, and often using diuretics.
