What it's for (Indications)
- Norethisterone oenanthate + estradiol valerate, marketed under various brand names such as Femi-Ject or Cyclofem, is indicated exclusively for the prevention of pregnancy.
- This combined injectable contraceptive is designed for monthly administration, offering a highly effective and reversible method of contraception.
- It is suitable for women seeking a reliable long-acting contraceptive option that does not require daily adherence, providing convenience and consistent protection against unintended pregnancy.
- Its primary role is to provide systemic hormonal contraception, and it is not indicated for the treatment of any specific gynecological conditions beyond its contraceptive effect.
- Before initiating treatment, a thorough medical history and physical examination, including a blood pressure measurement, must be performed to assess suitability.
Dosage Information
| Type | Guideline |
|---|---|
| Standard | This medication is administered via deep intramuscular injection, typically into the gluteal or deltoid muscle. The usual regimen involves a single 1 mL injection containing 50 mg of norethisterone oenanthate and 5 mg of estradiol valerate, given once every 28 to 30 days. The first injection should be given on the first day of the menstrual cycle (within the first 5 days of menses) to ensure immediate contraceptive efficacy. Subsequent injections should be given at regular intervals, ideally every 30 ± 3 days (not less than 27 days and not more than 33 days apart), to maintain contraceptive protection. Delaying the injection beyond this window may compromise efficacy and necessitate the use of backup contraceptive methods. No dose adjustment is required for body weight or age within the reproductive years. Transitioning from other hormonal contraceptives requires specific guidance from a healthcare professional. |
Safety & Warnings
Common Side Effects
- Patients using norethisterone oenanthate + estradiol valerate may experience a range of side effects, some common and others less frequent but potentially serious.
- Common side effects include menstrual irregularities (such as spotting, breakthrough bleeding, or amenorrhea), weight changes (gain or loss), headache, breast tenderness or pain, nausea, abdominal discomfort, mood changes (including depression), dizziness, and local injection site reactions (pain, redness, swelling).
- Less common but more serious adverse effects can include thromboembolic events (deep vein thrombosis, pulmonary embolism, myocardial infarction, stroke), hypertension, gallbladder disease, liver dysfunction, and worsening of pre-existing conditions like migraines.
- If severe or persistent side effects occur, particularly symptoms indicative of thrombosis (e.
- g.
- , sudden severe chest pain, shortness of breath, sudden severe headache, visual disturbances), immediate medical attention is required.
- Regular follow-up appointments are crucial to monitor for potential adverse effects.
Serious Warnings
- Black Box Warning: WARNING: CIGARETTE SMOKING AND SERIOUS CARDIOVASCULAR EVENTS. Cigarette smoking increases the risk of serious cardiovascular events from combined hormonal contraceptive (CHC) use. This risk increases with age, particularly in women over 35 years of age, and with the number of cigarettes smoked. For this reason, CHCs, including norethisterone oenanthate + estradiol valerate, are contraindicated in women who are over 35 years of age and smoke. The use of combined hormonal contraceptives is associated with an increased risk of serious cardiovascular adverse events including myocardial infarction, stroke, and venous thromboembolism (e.g., deep vein thrombosis and pulmonary embolism). This risk is greater in women with other underlying risk factors for cardiovascular disease or those with pre-existing cardiovascular conditions. Patients should be strongly advised not to smoke while using this medication. Any new onset or worsening of symptoms suggestive of a thromboembolic event requires immediate medical evaluation and discontinuation of the drug. Before prescribing, a thorough assessment of cardiovascular risk factors, including smoking status, should be conducted.
- Use of norethisterone oenanthate + estradiol valerate is associated with increased risks of serious cardiovascular events, particularly in women who smoke cigarettes.
- This risk increases with age and heavy smoking (≥15 cigarettes per day) and is especially pronounced in women over 35 years of age.
- Patients should be strongly advised not to smoke while using this medication.
- Other serious warnings include an increased risk of venous thromboembolism (VTE), arterial thromboembolism (ATE), stroke, and myocardial infarction.
- Blood pressure should be monitored regularly as hypertension can develop or worsen.
- Discontinue treatment if severe or new onset migraines with aura occur.
- Liver function should be assessed before and during treatment, and the medication should be discontinued if jaundice or liver dysfunction develops.
- There is a small increased risk of breast cancer and cervical cancer associated with combined hormonal contraceptive use.
- Diabetic patients should be monitored for changes in glucose tolerance.
- Psychiatric disorders, particularly depression, should be monitored, and discontinuation considered if clinically significant depression occurs.
- Patients should be aware of the possibility of delayed return to fertility after discontinuation.
How it Works (Mechanism of Action)
Norethisterone oenanthate + estradiol valerate exerts its contraceptive effects through the synergistic actions of its two hormonal components. Estradiol valerate, an estrogen, primarily works by suppressing the release of follicle-stimulating hormone (FSH) from the pituitary gland, which inhibits follicular development. It also helps stabilize the endometrial lining, reducing the incidence of breakthrough bleeding. Norethisterone oenanthate, a progestin, is the main contraceptive agent. It acts by suppressing the luteinizing hormone (LH) surge, thereby preventing ovulation. Additionally, it causes thickening of the cervical mucus, which makes it impenetrable to sperm, and induces endometrial atrophy, making the uterine lining unfavorable for implantation of a fertilized egg. The combined effect ensures high contraceptive efficacy by simultaneously preventing ovulation, impairing sperm transport, and inhibiting implantation.