Half life of spironolactone?

What is the half-life of spironolactone?

Spironolactone has an elimination half-life of about 1.4 hours (for the parent drug) [1].

Its active metabolites last longer, which is why the drug’s clinical effect extends beyond the parent half-life [1].

Does spironolactone’s half-life differ from its active metabolites?

Yes. The parent compound clears quickly (half-life around 1.4 hours) [1], while canrenone and other metabolites persist longer, contributing to the sustained diuretic/antihypertensive effect [1].

Why does the half-life matter clinically?

Because spironolactone’s effect depends partly on metabolites with longer persistence, dosing is typically based on ongoing effect rather than just the parent drug’s short half-life [1]. This can be relevant when adjusting therapy for people with conditions that affect drug clearance (for example, severe kidney or liver impairment) [1].

Sources

1. DrugBank - Spironolactone Half-Life