| Item |
Information |
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Drug Groups
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approved |
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Description
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A semisynthetic alkylated estradiol with a 17-alpha-ethinyl substitution. It has high estrogenic potency when administered orally, and is often used as the estrogenic component in oral contraceptives. [PubChem] |
| Indication |
For treatment of moderate to severe vasomotor symptoms associated with the menopause, female hypogonadism, prostatic carcinoma-palliative therapy of advanced disease, breast cancer, as an oral contraceptive, and as emergency contraceptive. |
| Pharmacology |
Ethinyl estradiol is a synthetic derivative of the natural estrogen estradiol. It is one of two estrogens currently used in oral contraceptive pills. The other, mestranol, is converted to ethinyl estradiol before it is biologically active. Ethinyl estradiol and norethindrone are used together as an oral contraceptive agent. |
| Toxicity |
Oral, mouse LD50: 1737 mg/kg. Symptoms of overdose include nausea and vomiting, and withdrawal bleeding may occur in females. |
| Affected Organisms |
| • |
Humans and other mammals |
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| Biotransformation |
Hepatic. 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 |
Rapid and complete absorption follows oral intake of ethinyl estradiol (bioavailability 43%). |
| Half Life |
36 +/- 13 hours |
| Protein Binding |
97% |
| External Links |
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