From the Guidelines
Spironolactone is contraindicated during pregnancy and should be discontinued if pregnancy occurs or is planned. This potassium-sparing diuretic can cause fetal damage due to its anti-androgenic effects, which can lead to feminization of male fetuses and interfere with normal male genital development when administered during critical periods of fetal development 1. The most recent evidence from 2024 supports controlling blood pressure to 110–135/85 mmHg to reduce the risk of accelerated maternal hypertension but also to minimize impairment of fetal growth, and recommends that individuals of childbearing potential switch from spironolactone to an alternative antihypertensive medication approved during pregnancy 1.
Key Considerations
- Spironolactone is classified as FDA pregnancy category C in the first trimester and category D in later pregnancy due to its anti-androgenic effects
- Women of childbearing potential who are taking spironolactone should use effective contraception
- If pregnancy occurs or is planned, spironolactone should be discontinued and alternative medications considered
- Safer alternatives for patients requiring treatment of conditions like heart failure, hypertension, or edema during pregnancy include methyldopa, labetalol, or hydralazine 1
Alternative Treatments
- Methyldopa, labetalol, and long-acting nifedipine are effective and safe in pregnancy
- Hydralazine may be considered in the acute management of hypertension in pregnancy or severe preeclampsia
- Diuretics are not recommended for blood pressure control in pregnancy but may be used during late-stage pregnancy if needed for volume control 1
From the FDA Drug Label
Based on mechanism of action and findings in animal studies, spironolactone may affect sex differentiation of the male during embryogenesis [see Data]. Rat embryofetal studies report feminization of male fetuses and endocrine dysfunction in females exposed to spironolactone in utero... Because of the potential risk to the male fetus due to anti-androgenic properties of spironolactone and animal data, avoid spironolactone in pregnant women or advise a pregnant woman of the potential risk to a male fetus.
Spironolactone use in pregnancy is not recommended due to the potential risk of affecting sex differentiation of the male fetus during embryogenesis. The drug's anti-androgenic properties and animal data support this precaution.
- Key considerations:
- Potential risk to the male fetus
- Animal data showing feminization of male fetuses and endocrine dysfunction in females
- Recommendation to avoid spironolactone in pregnant women or advise them of the potential risk 2
From the Research
Spironolactone in Pregnancy
There are no research papers provided to directly assist in answering the question about the use of spironolactone in pregnancy.
Available Information on Spironolactone
- Spironolactone is a potassium-sparing diuretic with anti-aldosterone effects, used in the management of hypertension 3 and heart failure 4, 5.
- It has been shown to be effective in improving blood pressure in patients with resistant hypertension 3.
- Spironolactone is also used in the treatment of edema in patients with cirrhosis and other conditions 5.
- The drug can cause hyperkalemia, gynecomastia, and renal insufficiency as major adverse effects 3.
Mechanism of Action
- Spironolactone works primarily in the distal tubule and collecting tubule, inhibiting the action of aldosterone and impairing tubular reabsorption of sodium 6.
- It has a potassium-sparing effect, making it useful in patients with hypokalemia or at risk of hypokalemia 6.
Recent Studies
- A recent study found that spironolactone 100 mg/day for 96 hours in patients with acute heart failure did not enhance decongestion but altered potassium homeostasis 7.
- Another study discussed the use of a liquid suspension formulation of spironolactone, which may be beneficial for patients with heart failure who have difficulty swallowing tablets 5.