How Do Potassium-Sparing Diuretics Work?

Diuretics also known aswaterpills are a class of drugs that causediuresis(increased production ofurineby the kidneys). Diuretics are drugs that work on the kidneys to remove electrolytes such assodiumandchloridefrom the bodyinthe urine. These electrolytes draw water along with them; thus, excess water also gets eliminated in the urine. They are used to treat conditions associated with the presence of excess sodium and water in the body such ashypertensionand fluid overload in the body that may damagemajororgans such as theheartand causeedema(accumulation of fluid in the body tissues causing swelling, usually seen due to damage to the small vessels).

Potassium-sparing diuretics are drugs that cause the excretion of sodium and water while preventing the loss of potassium in the urine. There are several drugs in this class, and each has a different mechanism of action.

• Sodium channel inhibition:一些药物通过抑制钠离子通道在thedistalpart of thenephron, distaltubule, and collecting ducts where the sodium is reabsorbed. As these channels are blocked, the uptake of sodium is blocked and transepithelial potential is not generated; thus, the excretion of potassium is decreased.
• Aldosteroneantagonism:aldosterone is ahormonethat increases thereabsorption钠和水。这些药物抑制aldosterone activity by binding to aldosterone receptors present on the collecting ducts and decrease the reabsorption of sodium and water.

Potassium-sparing diuretics are considered weak diuretics that are usually given along with other diuretics.

Potassium-sparing diuretics are used for:

• Hypertension (high blood pressure)
• Congestive heart failure(the heart cannot pump enoughbloodthat the body needs)
• Edematous conditions (swelling of the body caused by the accumulation of excess fluid)
• Primaryaldosteronismor Conn’ssyndrome(excess aldosterone production by theadrenal gland)
• Secondary aldosteronism (increase in production of aldosterone caused by conditions such asheart failureand decrease inrenalflow)
• Prevention of hypokalaemia (low potassium levels in the blood) occurring when other diuretics are used
• Hirsutism(increase in the growth of facial hair in females)
• Polycystic ovarian syndrome

The side effects associated with potassium-sparing diuretics include:

• Hyperkalemia(increased levels of potassium in the blood)
• Nauseaand vomiting
• Abdominaldiscomfort
• Headache
• Drowsiness
• Confusion
• Ataxia(loss ofcontrolon bodily movements due to lack of coordination between muscles andbrain)
• Kidneystones
• Gynecomastia(enlargement of breasts in males)
• Impotence
• Hyperchloremicmetabolicacidosis(caused by loss ofbicarbonate)
• Menstrualirregularities
• Hypersensitivity reaction

The information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with yourdoctororpharmacistto make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking yourmedicationand never change your dose or frequency without consulting your doctor.

Genericand brand names of potassium-sparing diuretics drugs include:

• Aldactone
• Amiloride (Midamor)
• Spironolactone(CaroSpir)
• Triamterene(Dyrenium)