Generic Name

Ethinyl Estradiol; Ethynodiol Diacetate

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Classification

FDA Approved Indications

• Prevention of pregnancy

Mechanism of Action

The combination provides estrogen and progestin effects, inhibiting the hypothalamic-pituitary-ovarian axis, preventing ovulation, thickening cervical mucus, and altering the endometrial lining to prevent implantation.

Dosage and Administration

Adult: Typically one tablet daily at the same time each day, starting on the first day of the menstrual cycle or as directed by the healthcare provider.

Pediatric: Not indicated for pediatric use.

Geriatric: Not established; caution advised in women of advanced age due to increased cardiovascular risks.

Renal Impairment: Adjustments generally not necessary but monitor for adverse effects.

Hepatic Impairment: Use with caution; contraindicated in severe hepatic impairment.

Pharmacokinetics

Absorption: Well absorbed orally.

Distribution: Bound to plasma proteins, primarily albumin and sex hormone-binding globulin.

Metabolism: Metabolized extensively in the liver via first-pass effects.

Excretion: Excreted primarily in the feces via biliary route and urine.

Half Life: Approximately 13 hours for ethinyl estradiol; similar for ethynodiol diacetate.

Contraindications

• History of thromboembolic events (DVT, PE)
• Hormone-sensitive malignancies (e.g., breast cancer)
• Undiagnosed abnormal vaginal bleeding
• Severe hepatic disease
• Known pregnancy

Precautions

• Use with caution in women over 35 who smoke, due to increased risk of cardiovascular events.
• Monitor blood pressure periodically.

Adverse Reactions - Common

• Nausea or vomiting (Common)
• Breast tenderness (Common)
• Headaches (Common)
• Fluid retention (Common)

Adverse Reactions - Serious

• Deep vein thrombosis (DVT) (Serious (rare))
• Pulmonary embolism (PE) (Serious (rare))
• Stroke (Serious (rare))
• Myocardial infarction (Serious (rare))

Drug-Drug Interactions

• Anticonvulsants (e.g., phenytoin, carbamazepine)
• Antibiotics (e.g., rifampin)
• Other CYP450 inducers or inhibitors

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Patient/Family Teaching

• Take medication exactly as prescribed, at the same time daily.
• Report signs of blood clots (leg pain, chest pain, sudden headache).
• Use additional contraception during medication start and discontinuation.
• Discuss smoking cessation, especially if over 35 years old.

Special Considerations

Black Box Warnings:

• Smoking increases risk of cardiovascular events, especially in women over 35.
• Risk of thromboembolism associated with combined oral contraceptives.

Genetic Factors: Most effective when patient’s metabolism is not genetically altered to increase risks.

Lab Test Interference: May affect blood clotting tests or thyroid function tests.

Overdose Management

Signs/Symptoms: Nausea, vomiting, withdrawal bleeding.

Treatment: Supportive care; no specific antidote; symptomatic treatment as needed.

Storage and Handling

Storage: Store at room temperature, away from moisture and heat.

Stability: Stable until the expiration date printed on the packaging.