diuretics
History of diuretic use:
Use of mercurials to Rx syphilis & their common diuretic side effect led to the use of mercurial diuretics in 1920's & despite toxicity, these potent loop diuretics dominated Rx of CCF until advent of modern loop diuretics.
The diuretic side effect of sulphonamide
antibiotics resulted in acetazolamide - a carbonic anhydrase inhibitor 1st used in 1930's.
Further research on sulphonamides led to thiazide diuretics in the 1950's & then, in early 1960's, to frusemide, the protypic sulphonamide diuretic in this group.
Potential indications for diuretics:
General Pharmacology of Diuretics:
Diuretics are substances that incr. urine volume & incr. net loss of water/solutes & are used for:
All act either by osmotic effects or on specific renal tubular sites although may have indirect effects at sites distal in nephron:
All tend to distort normal composition of body fluids:
direct effect on altered ion excretion rates;
distorted nephron axial flow → abnormal function (eg. incr. flow → incr. K excretion);
homeostatic mechanisms may alter fluid composition;
Classes of diuretics
potassium losing diuterics
potassium-sparing diuretics