Molecule

Drug Groups

approved

Description

The 3-cyclopentyl ether of ethinyl estradiol.

Indication

Used in hormone replacement therapy, treating symptoms of menopause such as hot flashes. Also used to treat breast and prostate cancer.

Pharmacology

Quinestrol is the 3-cyclopentyl ether of ethinyl estradiol (the active metabolite). After gastrointestinal absorption, it is stored in adipose tissue where it is slowly released and metabolized principally to the parent compound, ethinyl estradiol. Ethinyl estradiol is a synthetic derivative of the natural estrogen estradiol.

Toxicity

Symptoms of overdose include nausea and vomiting, and withdrawal bleeding may occur in females.

Affected Organisms

Biotransformation

Metabolized principally to the parent compound, ethinyl estradiol. Ethinyl estradiol is metabolized in the liver. Quantitatively, the major metabolic pathway for ethinyl estradiol, both in rats and in humans, is aromatic hydroxylation, as it is for the natural estrogens.

Absorption

Absorbed following oral administration.

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