thiazide

Q: What is spironolactone used for?

Spironolactone is a diuretic drug that is used to treat conditions related to edema , hypertension , and hormonal imbalances. Examples include cirrhosis , congestive heart failure , nephrotic syndrome (a sign of kidney malfunction), and primary hyperaldosteronism (Conn syndrome). It also is used to treat certain forms of acne , as well as hirsutism, and is used in transgender women as part of gender-affirming hormone therapy .

Q: How does spironolactone work?

Spironolactone works by blocking receptors for the hormone aldosterone , causing increased excretion of sodium and water. The actions of spironolactone also result in potassium conservation, which is important for maintaining cell function. Spironolactone also has antiandrogen effects, which can reduce levels of male hormones such as testosterone .

Q: What are the side effects of spironolactone?

Spironolactone has various side effects. Some examples include dizziness, gastrointestinal upset, gynecomastia (enlargement of breast tissue in males), headache , menstrual irregularities, and skin rashes. It can also cause hyperkalemia (elevated potassium levels), which can alter heart rhythm.

drug

Also known as: benzothiadiazide

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development of drugs

In pharmaceutical industry: Emergence of modern diseases and treatment
, the discovery of thiazide diuretics. For decreasing death and disability from cancer, one very important step was the development of cancer chemotherapy.
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In pharmaceutical industry: Hypertension
…and became the first successful thiazide diuretic. While acetazolamide causes diuresis by increasing sodium bicarbonate excretion, chlorothiazide was found to increase sodium chloride excretion. More importantly, by the mid-1950s it had been shown that chlorothiazide lowers blood pressure in patients with hypertension. Over the next 50 years many other classes…
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drug interactions

In pharmaceutical industry: Drug interactions
For example, thiazide diuretics (which cause potassium loss) can interact with other diuretics that cause potassium retention in such a way that the combination has no significant impact on body potassium. Cancer chemotherapeutic agents are often given in combination because cellular interactions (such as inhibiting cell replication…
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use as diuretic

In diuretic
…most widely used diuretics, the benzothiadiazides (e.g., chlorothiazide), interfere with the reabsorption of salt and water by the kidney tubules. Instead of being reabsorbed, the salt and water are ultimately excreted, thus increasing the flow of urine. After they were synthesized in the late 1950s, the benzothiadiazides replaced most other…
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In drug: Renal system drugs
The thiazide class of diuretics, which are widely used in the treatment of hypertension, interferes with salt reabsorption in the first part of the distal tubule. A mild diuresis results in which sodium, potassium, and chloride ions are eliminated in the urine. Examples of these drugs…
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spironolactone

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References & Edit History Quick Facts & Related Topics

spironolactone

drug

Also known as: Aldactone A

Written by Kara Rogers

Fact-checked by The Editors of Encyclopaedia Britannica

Article History

Related Topics:: hormone; diuretic; antagonism

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What is spironolactone used for?

How does spironolactone work?

What are the side effects of spironolactone?

spironolactone, diuretic drug that is used primarily to treat conditions related to edema (fluid retention), hypertension (high blood pressure), and hormone imbalances. The therapeutic effects of spironolactone were first described in the late 1950s. In 1960 the drug was approved for the treatment of hypertension.

Mechanism of action

Spironolactone exerts its effects by binding to and blocking receptors for the hormone aldosterone, which is secreted by the adrenal glands and functions to regulate sodium and water retention and potassium excretion. Inhibition of aldosterone activity results in increased excretion of sodium and water, helping to reduce blood volume and blood pressure. At the same time, this conserves potassium, which is essential for maintaining cell function, particularly in the case of muscle cells. Spironolactone also blocks androgen receptors, which reduces the synthesis of androgen hormones such as testosterone.

Uses

Spironolactone often is prescribed to treat edema associated with conditions such as cirrhosis, congestive heart failure, and nephrotic syndrome, which is a sign of kidney malfunction. It also is used in the treatment of resistant hypertension, in which blood pressure remains high despite other medications, and primary hyperaldosteronism (Conn syndrome), in which the body produces too much aldosterone.

The antiandrogen effects of spironolactone are valuable in the treatment of certain hormone imbalances. Examples include acne associated with polycystic ovary syndrome (PCOS), which causes increased oil production in the skin, and hirsutism, which is characterized by excessive hair growth because of elevated levels of androgens. Spironolactone is also used in transgender women as part of gender-affirming hormone therapy; when combined with estrogen therapy, reductions in testosterone levels induced by the drug can help facilitate the development of feminine secondary sex characteristics.

Side effects

Spironolactone is associated with various side effects, some more severe than others. Relatively mild effects include dizziness, gastrointestinal upset, gynecomastia (enlargement of breast tissue in males), headache, menstrual irregularities, and skin rashes. More severe adverse effects include hyperkalemia (elevated potassium levels), which can lead to dangerous alterations in heart rhythm, and exacerbation of preexisting diseases or disorders associated with alterations in electrolyte balance. Such adverse effects can be avoided through close monitoring of potassium levels and kidney function.

Kara Rogers