Ethinyl Estradiol

Absorption

A 30μg oral dose of ethinylestradiol reaches a Cmax of 74.1±35.6pg/mL, with a Tmax of 1.5±0.5h, and an AUC of 487.4±166.6pg*h/mL. A 1.2mg dose delivered via a patch reaches a Cmax of 28.8±10.3pg/mL, with a Tmax of 86±31h, and an AUC of3895±1423pg*h/mL.

Toxicity

Female patients experiencing and overdose may present with withdrawal bleeding, nausea, vomiting, breast tenderness, abdominal pain, drowsiness, and fatigue. Overdose should be treated with symptomatic and supportive care including monitoring for potassium concentrations, sodium concentrations, and signs of metabolic acidosis.

Indications

Ethinylestradiol is combined with other drugs for use as a contraceptive, premenstrual dysphoric disorder, moderate acne, moderate to severe vasomotor symptoms of menopause, prevention of postmenopausal osteoporosis.

Background

Ethinylestradiol was first synthesized in 1938 by Hans Herloff Inhoffen and Walter Hohlweg at Schering. It was developed in an effort to create an estrogen with greater oral bioavailability. These properties were achieved by the substitution of an ethinyl group at carbon 17 of estradiol. Ethinylestradiol soon replaced mestranol in contraceptive pills.
Ethinylestradiol was granted FDA approval on 25 June 1943.

Pharmacokinetics

Ethinylestradiol is a synthetic estrogen that decreases luteinizing hormone to decrease endometrial vascularization, and decreases gonadotrophic hormone to prevent ovulation. It has a long duration of action as it is taken once daily, and a wide therapeutic index as overdoses are generally not associated with serious adverse effects. Patients should be counselled regarding the risks of thrombotic events.

First aid

Skin Contact: Flood all areas of body thathave contacted the substance with water. Do not wait toremove contaminated clothing; do it under the water stream.Use soap to help assure removal. Isolate contaminatedclothing when removed to prevent contact by others. EyeContact: Remove any contact lenses at once. Immediatelyflush eyes well with copious quantities of water or normalsaline for at least 20-30 min. Seek medical attention.Inhalation: Leave contaminated area immediately; breathefresh air. Proper respiratory protection must be supplied toany rescuers. If coughing, difficult breathing, or any othersymptoms develop, seek medical attention at once, even ifsymptoms develop many hours after exposure. Ingestion:Contact a physician, hospital, or poison center at once. Ifthe victim is unconscious or convulsing, do not inducevomiting or give anything by mouth. Assure that thepatient’s airway is open and lay him on his side with hishead lower than his body and transport immediately to a medical facility. If conscious and not convulsing, give aglass of water to dilute the substance. Vomiting should notbe induced without a physician’s advice.

The Uses of Ethinyl Estradiol

Ethinyl estradiol is used to prevent pregnancy. It works by stopping a woman's egg from fully developing each month. The egg can no longer accept a sperm and fertilization (pregnancy) is prevented.

Metabolism

Ethinylestradiol can be glucuronidated by UGT1A1, UGT1A3, UGT1A4, UGT1A9, and UGT2B7. Ethinylestradiol is also sulfated by SULT1A1, SULT1A3, and SULT1E1. Ethinylestradiol can also be hydroxylated at positions 2, 4, 6, 7, and 16 by CYP3A4, CYP3A5, CYP2C8, CYP2C9, and CYP1A2. These hydroxylated metabolites can be methylated by catechol-O-methyltransferase. The methoxy metabolites can in turn be sulfated or glucuronidated.

storage

Color Code—Blue: Health Hazard/Poison: Storein a secure poison location. Prior to working with thischemical you should be trained on its proper handling andstorage. Store in a refrigerator under an inert atmosphereand protect from exposure to light.