Diuretics are drugs used to increase the amount of urine produced by the kidneys and increase the excretion of sodium and other electrolytes.
All diuretics produce a similar effect, although their modes of action may differ.
They are most commonly used in patients with cardiac conditions, to treat the oedema and congestion associated with heart failure, and in renal disease and liver cirrhosis. They affect the filtration and concentration of the circulating blood volume.
There are five classes of diuretics: thiazides and thiazide-like diuretics; loop diuretics; carbonic anhydrase inhibitors; potassium-sparing diuretics; and osmotic diuretics.
Hypertension is much more common in the elderly, and in this age-group, isolated systolic hypertension is particularly common.
Although thiazide and thiazide-like diuretics are indispensable drugs in the treatment of hypertension, their role as first-line or even second-line drugs is a provoking debate.
Diuretics should remain the preferred drugs for initial treatment in many hypertensive patients, whereas the cons side will contend that emerging evidence from outcome-based studies is casting doubt on the role of these drugs as first-line and even second-line antihypertensive treatment.
Diuretics may cause several other adverse reactions.
