If you remember from Part 1, thiazide diuretics excrete sodium from our body through the urine, but they also deplete the body of potassium, a crucial mineral that our system needs to maintain a regular heartbeat and nerve activity.
To correct this problem, pharmaceutical companies, always trying to help, came up with a new kind of hypertension medication: potassium-sparing diuretics.
This kind of medication blocks the action of aldosterone, a hormone that is secreted into the blood by the adrenal glands, which sit on top of each kidney. When the level of this hormone is high, we retain sodium which contributes to high blood pressure. Potassium-sparing diuretics block the action of aldosterone and as a result, more sodium, along with water, is lost in the urine.
Aldosterone also stimulates the secretion of potassium from the blood through the urine. Potassium-sparing diuretics cause the kidneys to conserve potassium, keeping it in the body instead of being excreted through the kidneys and the urine. As you can see, these diuretics do less damage than the thiazide diuretics because they spare potassium.
Side Effects of potassium-sparing diuretics
However, this medication sometimes can do too much of a good job and elevates the level of potassium beyond a healthy level. This can cause heart arrhythmias. Because these diuretics are weaker than thiazide diuretics, they are used in combination with other diuretics.
Potassium-sparing diuretics also cause the loss of magnesium, a mineral necessary to regulate blood pressure and for overall heart function. A loss of magnesium caused by long term therapy can be a major risk for heart failure.
Furosemide has sometimes been used for treating hypertension, congestive heart failure, and other conditions that cause fluid retention. It induces the kidneys to inhibit the reabsorption of sodium into the body as well as potassium. Again, getting rid of extra sodium is beneficial for reducing blood pressure but the loss of potassium is a harmful side effect.
Most common potassium-sparing diuretics
Generic Name Brand Name
Spironolactone Aldactone, Aldactazide
Triamterene Dyremium, Maxzide, Dyazide
Generic name Brand Name
If you are currently taking hypertension medication do not suddenly stop taking it, as this could cause a heart attack or sudden death. Any change in your current medication should only be done in consultation with your doctor.