urine and feces. At least 20 different metabolites can be identified in urine and feces. Drospirenone and its metabolites are excreted in urine about 38% as glucuronide conjugates, 47% as sulfate conjugates, and less than 10% in unconjugated form. In feces, excretion is about 17% glucuronide conjugates, 20% sulfate conjugates, and 33% unconjugated. The elimination half-life of drospirenone is between 25 and 33 hours. The half-life of drospirenone is unchanged with repeated administration. Elimination of drospirenone is virtually complete 10 days after the last dose. Chemistry Drospirenone, also known as 1,2-dihydrospirorenone or as 17β-hydroxy-6β,7β:15β,16β-dimethylene-3-oxo-17α-pregn-4-ene-21-carboxylic acid, γ-lactone, is a synthetic steroidal 17α-spirolactone, or more simply a spirolactone. It is an analogue of other spirolactones like spironolactone, canrenone, and spirorenone. Drospirenone differs structurally from spironolactone only in that the C7α acetyl thio substitution of spironolactone has been removed and two methylene groups have been substituted in at the C6β–7β and C15β–16β positions. Spirolactones like drospirenone and spironolactone are derivatives of progesterone, which likewise has progestogenic and antimineralocorticoid activity. The loss of the C7α acetylthio group of spironolactone, a compound with negligible progestogenic activity, appears to be involved in the restoration of progestogenic activity in drospirenone, as SC-5233, the analogue of spironolactone without a C7α substitution, has potent progestogenic activity similarly to drospirenone. History Drospirenone was patented in 1976 and introduced for medical use in 2000. Schering AG of Germany has been granted several patents on the production of drospirenone, including WIPO and US patents, granted in 1998 and 2000, respectively. It was introduced for medical use in combination with ethinylestradiol as a combined birth control pill in 2000. Drospirenone is sometimes described as a "fourth-generation" progestin based on its time of introduction. The medication was approved for use in menopausal hormone therapy in combination with estradiol in 2005. Drospirenone was introduced for use as a progestogen-only birth control pill in 2019. A combined birth control pill containing estetrol and drospirenone was approved in 2021. Society and culture Generic names Drospirenone is the generic name of the drug and its , , , and , while drospirénone is its . Its name is a shortened form of the name 1,2-dihydrospirorenone or dihydrospirenone. Drospirenone is also known by its developmental code names SH-470 and ZK-30595 (alone), BAY 86-5300, BAY 98-7071, and SH-T-00186D (in combination with ethinylestradiol), BAY 86-4891 (in combination with estradiol), and FSN-013 (in combination with estetrol). Brand names Drospirenone is marketed in