Dimethisterone

Dimethisterone (INN, USAN, BAN) (brand names Lutagan, Secrosteron), also known as 6α,21-dimethylethisterone, is a steroidal progestin related to ethisterone (17α-ethinyltestosterone). It was developed by the British pharmaceutical company British Drug Houses (which subsequently merged with Merck KGaA) and was first reported in the medical literature in 1959, with introduction for medical use as Secrosteron following in the same year.

Contents

• Medical vocabulary what does dimethisterone mean
• How to pronounce dimethisterone
• References

Dimethisterone was derived from modification of ethisterone via introduction of methyl groups at the C6α and C21 positions. Relative to ethisterone, it is 12 times as potent orally as a progestogen in animals (Clauberg test), and, unlike ethisterone, is a pure progestogen with no androgenic (or estrogenic) activity in animals even at very high doses (although some weak antimineralocorticoid activity was observed at high doses in animals). However, in spite of its improved potency over ethisterone, it is a weak progestogen relative to most other progestins, in fact one of the weakest known.

Dimethisterone was introduced in the United States as an oral contraceptive in combination with high doses of ethinylestradiol under the brand name Oracon (25 mg dimethisterone, 100 μg ethinylestradiol) in 1965. Due to the fact that it contains a weak progestogen in combination with a large dose of a potent estrogen, this preparation was eventually found to be associated with a substantially increased risk of endometrial cancer in women, and is now no longer marketed.

The improved potency of dimethisterone due to 6α-methylation reportedly served as the basis for the synthesis of medroxyprogesterone acetate. Whereas hydroxyprogesterone acetate (the 6α-demethylated analogue of medroxyprogesterone acetate) is around twice as potent as ethisterone orally, medroxyprogesterone acetate shows 10 to 25 times the potency of ethisterone.