May 19 2022

Classification of the active ingredient spironolactone

Risk level in pregnancy: This medicine is classified as Category C.

At lower doses than the maximum used in human clinical practice, there has been no adverse effects on fetus or embryo in laboratory animals, although it has been observed a lower rate of live fetuses and a higher proportion of resorptions.

As is known, spironolactone has an antiandrogenic effect, so it can affect the process of sexual differentiation in male embryos. It was observed that treatment with high doses of spironolactone causes feminization of male fetuses during embryogenesis.

Update 18.07.2009

Meaning of category C

Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.