Ethinyl Estradiol/Norgestimate: Drug Information
1. Drug Name
Generic Name
Ethinyl Estradiol/Norgestimate
Brand Name(s)
- Pakistan: BrandX
- India: BrandY
- US: Ortho Tri-Cyclen, Sprintec, Tri-Sprintec
- UK: Cilest
2. Pharmacological Class
Class
Contraceptive - Estrogen-Progestin Combination
Subclass
Monophasic Oral Contraceptive
3. Mechanism of Action
Ethinyl estradiol and norgestimate act together to inhibit ovulation by suppressing the release of gonadotropins. They also alter the cervical mucus and endometrium, making it difficult for sperm to reach the uterus and for a fertilized egg to implant.
4. Indications
Primary Indications
- Prevention of pregnancy
Off-label Uses
- Management of acne in women
- Regulation of menstrual cycles
5. Dosage and Administration
Standard Dosage
The dosage regimen depends on the specific formulation and brand. Typically, one tablet daily for 21 days, followed by 7 days without tablets (for menstrual bleeding).
Route of Administration
Oral administration
Special Populations
- Pediatric: Safety and efficacy not established in girls who have not yet started menstruating.
- Geriatric: Generally not indicated in postmenopausal women.
6. Pharmacokinetics
Absorption
Rapidly absorbed from the gastrointestinal tract.
Distribution
Bioavailability is approximately 65%. Protein binding is high.
Metabolism
Metabolized in the liver.
Excretion
Excreted in the urine and feces.
Half-life
The elimination half-life of ethinyl estradiol is about 24 hours. The elimination half-life of norgestimate is approximately 10 hours.
7. Contraindications
- Pregnancy
- History of thromboembolic disorders
- Undiagnosed abnormal genital bleeding
8. Warnings and Precautions
- Increased risk of cardiovascular events
- Increased risk of thromboembolism
- Increased risk of breast and cervical cancer
9. Side Effects
Common Side Effects
- Nausea
- Headache
- Breast tenderness
Serious Side Effects
- Thromboembolic events (e.g., deep vein thrombosis, pulmonary embolism)
- Hypertension
- Cholestatic jaundice
10. Drug Interactions
Major Interactions
- Rifampin
- Barbiturates
Moderate Interactions
- Antibiotics (e.g., ampicillin, tetracycline)
- Anticonvulsants (e.g., phenytoin, carbamazepine)
Minor Interactions
- Ascorbic acid (vitamin C)
- Acetaminophen
11. Pregnancy and Lactation
Pregnancy Category
Category X - Contraindicated during pregnancy.
Breastfeeding Considerations
Not recommended during breastfeeding due to potential adverse effects on the infant.
12. Patient Counseling Information
- Take the medication exactly as prescribed.
- Use additional contraception if vomiting or diarrhea occur.
- Report any unusual or severe abdominal pain immediately.