Introduction
Jinteli is a combination hormonal medication containing norethindrone acetate and ethinyl estradiol. It is classified as a combination oral contraceptive that provides both estrogen and progestin components for the prevention of pregnancy. Jinteli is also FDA-approved for the treatment of moderate to severe vasomotor symptoms associated with menopause and for the prevention of postmenopausal osteoporosis in women at significant risk.
Mechanism of Action
Jinteli works through multiple mechanisms to prevent pregnancy. The ethinyl estradiol component suppresses follicle-stimulating hormone (FSH), while the norethindrone acetate component suppresses luteinizing hormone (LH), collectively inhibiting ovulation. Additionally, the progestin component alters the cervical mucus, making it less permeable to sperm, and changes the endometrial lining to reduce the likelihood of implantation.
For menopausal symptoms, the estrogen component helps alleviate vasomotor symptoms by stabilizing hypothalamic thermoregulation, while both hormones help maintain bone mineral density by reducing bone resorption.
Indications
- Prevention of pregnancy
- Treatment of moderate to severe vasomotor symptoms associated with menopause
- Prevention of postmenopausal osteoporosis in women at significant risk (only for women with an intact uterus)
Dosage and Administration
Standard dosing: One tablet daily for 28 consecutive days per menstrual cycle (21 active tablets followed by 7 inert tablets) Administration:- Take at approximately the same time each day
- Begin on first day of menstrual period or following Sunday after period begins
- For postpartum women not breastfeeding: may start 4 weeks postpartum
- Renal impairment: Use with caution
- Hepatic impairment: Contraindicated in hepatic disease
- Geriatric patients: Not indicated in postmenopausal women
- Adolescents: May be used after menarche
Pharmacokinetics
Absorption: Ethinyl estradiol is rapidly and completely absorbed; norethindrone acetate is rapidly absorbed and converted to norethindrone. Peak concentrations reached within 1-2 hours. Distribution: Both components are highly bound to plasma proteins (ethinyl estradiol: 98% bound to albumin; norethindrone: 96% bound to albumin and SHBG). Metabolism: Hepatic metabolism via cytochrome P450 system (primarily CYP3A4). Ethinyl estradiol undergoes extensive first-pass metabolism and enterophepatic recirculation. Elimination: Both components are eliminated primarily in urine and feces. Ethinyl estradiol half-life: ~24 hours; norethindrone half-life: ~8 hours.Contraindications
- Thrombophlebitis or thromboembolic disorders
- History of deep vein thrombosis or pulmonary embolism
- Cerebrovascular or coronary artery disease
- Known or suspected carcinoma of the breast
- Known or suspected estrogen-dependent neoplasia
- Undiagnosed abnormal genital bleeding
- Hepatic impairment or liver tumors
- Known or suspected pregnancy
- Hypersensitivity to any component of Jinteli
Warnings and Precautions
Boxed Warning: Increased risk of cardiovascular events, breast cancer, and endometrial cancer with postmenopausal use Additional warnings:- Increased risk of venous thromboembolism, stroke, and myocardial infarction
- Increased risk of hypertension
- Increased risk of liver tumors and gallbladder disease
- Carbohydrate and lipid metabolic effects
- Headache, including migraines
- Uterine bleeding irregularities
- Depression
- Possible increased risk of dementia in postmenopausal women
- Visual abnormalities and corneal curvature changes
Drug Interactions
Strong CYP3A4 inducers: Rifampin, carbamazepine, phenytoin, St. John's wort - may decrease contraceptive efficacy Strong CYP3A4 inhibitors: Ketoconazole, itraconazole - may increase estrogen levels Antibiotics: Ampicillin, tetracyclines - may decrease contraceptive efficacy Anticoagulants: Warfarin - may alter anticoagulant effect Anticonvulsants: Lamotrigine - may decrease lamotrigine levels HIV medications: Protease inhibitors, NNRTIs - may alter contraceptive efficacy Herbal supplements: St. John's wort - may decrease contraceptive efficacyAdverse Effects
Common (≥10%): Headache, breast pain, irregular uterine bleeding, nausea, abdominal pain Less common (1-10%): Weight changes, mood changes, libido changes, bloating, acne Serious (<1%): Venous thromboembolism, stroke, myocardial infarction, breast cancer, gallbladder disease, hepatic tumors, hypertension, hyperkalemiaMonitoring Parameters
- Blood pressure at baseline and periodically
- BMI and weight regularly
- Lipid profile periodically
- Liver function tests as clinically indicated
- Signs and symptoms of thromboembolism
- Breast examination annually and mammography as appropriate
- Pap smear as per screening guidelines
- Signs of depression
- Visual changes or ocular symptoms
- Glucose tolerance in women with risk factors for diabetes
- Bone mineral density in postmenopausal women using for osteoporosis prevention
Patient Education
- Take tablet at same time daily to maintain effectiveness
- Use backup contraception if vomiting or diarrhea occurs within 4 hours of dosing
- Notify healthcare provider immediately if severe abdominal pain, chest pain, shortness of breath, severe headaches, visual changes, or leg pain occurs
- This medication does not protect against HIV or other sexually transmitted diseases
- Regular follow-up appointments are necessary
- Report any unusual vaginal bleeding
- Smoking increases risk of serious cardiovascular side effects (women over 35 should not smoke)
- May take several cycles for menstrual pattern to regulate
- Notify all healthcare providers about Jinteli use, particularly before surgeries
- Store at room temperature away from moisture and light
References
1. FDA Prescribing Information: Jinteli (norethindrone acetate and ethinyl estradiol) 2. Curtis MG, et al. Menopausal Hormone Therapy: Benefits and Risks. Obstet Gynecol Clin North Am. 2022 3. Tepper NK, et al. Combined Hormonal Contraceptives and Thromboembolism: An Update. Contraception. 2021 4. Stuenkel CA, et al. Treatment of Symptoms of the Menopause: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2021 5. ACOG Practice Bulletin No. 206: Use of Hormonal Contraception in Women With Coexisting Medical Conditions. Obstet Gynecol. 2022 6. Manson JE, et al. Menopausal Hormone Therapy and Long-term Health Outcomes: The Women's Health Initiative Randomized Trials. JAMA. 2022