What is Spironolactone?
Spironolactone is a synthetic aldosterone receptor antagonist (block adrenergic, potassium-sparing diuretic, or arterial dilator). Aldosterone is essential in your body's water- and salt-balancing mechanisms. It became commercially available in 1960 after the FDA approved spironolactone as a mild diuretic. In fact, for longer than 30 years, it has been used to retain potassium [1, 2].
What Does Spironolactone Do?
Because spironolactone blocks the hormone aldosterone, it is used to treat heart failure and high blood pressure and, because of its anti-androgenic (blocking the effects of male sex hormones) properties, to treat oedema (fluid retention) associated with liver and kidney disease [2, 3].
It also helps with several other dermatological issues. The drug’s anti-androgenic effects make it useful where increased androgen production causes unwanted symptoms, and it may be used for acne, hidradenitis suppurativa (a condition characterised by lumps filled with pus under the skin), female pattern hair loss and hirsutism (excess hair growth) in females [4, 5, 1].
Spironolactone is also prescribed off-label for conditions associated with elevated testosterone levels, for example, polycystic ovary syndrome (PCOS) [2]. Androgens that crosstalk with the testes to maintain ‘sperm factories’ are also affected by spironolactone in the event of hormone therapy [6, 7].
Side Effects of Spironolactone
Spironolactone, a medication often used to treat conditions like high blood pressure and heart failure, can cause a variety of side effects.
Common side effects include:
- Diarrhoea
- Stomach cramps
- Nausea
- Vomiting is also a prominent side effect, and if not properly managed, it can lead to dehydration.
- headaches and dizziness
Patients may also experience irregular menstrual bleeding and changed menstruation. Men can experience gynecomastia or swelling and pain in the breasts with spironolactone use [2, 3, 7, 8, 9, 10, 11].
Serious side effects include high potassium levels, called hyperkalemia [8, 11, 2, 3, 7, 9].
Less common but severe adverse reactions include bleeding in the gut [12, 9], severe rashes [8], and muscle spasms or weakness [3].
In some cases, spironolactone can cause changes in libido, depression, and fatigue [9].
These are possible but variable side effects, so if you have an adverse reaction or your symptoms worsen or become more frequent, talk to your physician immediately.
Spironolactone and Pregnancy
Spironolactone, marketed under the brand name Aldactone, is a potassium-sparing diuretic prescribed for over three decades and induces antiandrogenic side effects [1]. Nevertheless, spironolactone is also administered with a birth control pill for conditions such as acne and polycystic ovary syndrome (PCOS) [7]. If pregnancy does occur, spironolactone can cause birth defects and poses risks for the mother and the baby [7].
Is it OK that I Accidentally Got Pregnant On Spironolactone?
If you have accidentally become pregnant while taking spironolactone, contact your doctor immediately. In some cases, the doctor may advise continuing with the spironolactone and not inducing an abortion, mainly if the pregnancy is advanced [7].
Yet spironolactone can cause birth defects and pregnancy complications if pregnancy should occur [7], as well as reduce the testosterone production rate and increase its metabolic clearance, which could theoretically have anti-androgenic effects on the fetus [17].
A survey of 54 patients receiving spironolactone reported side effects in 91% and that 80% of these direct or indirect effects were ‘androgenic’ – that is, due to the anti-androgenic nature of the drug, such as menstrual disturbances [15].
Although not FDA-approved as a contraceptive, spironolactone does impact fertility. This study demonstrated ovulation in 12% of spironolactone and 28% of placebo cycles [18].
Although for certain conditions, it’s a life-saving drug, it isn’t one to take during pregnancy due to risks to the foetus. If you have accidentally become pregnant on spironolactone, you need to make an appointment to see your healthcare practitioner.