The Four Groups Of Useful Diuretics
Of the entire drug classes, the only one that has consistently reduced the illness and death associated with high blood pressure when it’s the first treatment is the diuretic class and specifically the thiazide diuretics.
Diuretics, also known as “water pills,” lower blood pressure by forcing the body to rid itself of salt and water through the kidneys into the urine. Depending on the place in the kidneys where they’re active, diuretics rid the body of more or less salt and water. However, after a couple of months, the body overcomes the reduction in body fluids. At this point, it’s a reduction in the resistance to blood flow that accounts for the ongoing fall in blood pressure. Depending on where the medication is acting, diuretics are divided into different groups as follows:
1. Thiazide and thiazidelike diuretic group: Although they’re not the most effective drugs for ridding the body of excess salt and water, the most effective group for lowering blood pressure is the thiazide and thiazidelike diuretic group.
2. Loop diuretics: A second group, the loop diuretics, acts at the thick ascending limb of the loop of Henie, part of the filtering mechanism of the kidneys. These drugs have a potent effect on salt and water elimination.
3. Potassium-sparing diuretics: A third group, the potassium-sparing diuretics function at the late distal tubule and the collecting tubule of the nephron. The result is only a mild increase in sodium excretion and chloride excretion but a tendency to reduce the excretion of potassium. Because the other diuretics cause potassium loss, the potassium-sparing diuretics are important for maintaining body potassium.
4. Aldosterone-antagonist group: The final group of useful diuretics is the aldosterone-antagonist group. In the United States, only one is currently available, spironolactone. This group blocks the action of aldosterone, a natural hormone that causes salt and water retention. If its action is blocked, more salt and water is excreted into the urine while potassium loss is reduced. These drugs could be included in the potassium-sparing group, but they go about lowering blood pressure in an altogether different manner than the potassium sparing group – they deactivate.