1. Clinical Overview
Progesterone (100mg/ml) is a high-concentration, sterile, micronized injectable formulation of the natural female sex hormone, progesterone. It is a critical agent in reproductive medicine and gynecology, primarily used for luteal phase support in assisted reproductive technology (ART) cycles, secondary amenorrhea, and dysfunctional uterine bleeding. The micronized formulation in oil (typically sesame or castor oil) ensures improved solubility and sustained release from the intramuscular injection site.
| Onset | Duration | Bioavailability |
|---|---|---|
| Within 2-4 hours after intramuscular injection. | Approximately 24 hours, requiring daily administration for sustained effect. | Approaches 100% for intramuscular administration. |
2. Mechanism of Action
Progesterone is the principal endogenous progestogen. It binds to and activates the intracellular progesterone receptor (PR), a nuclear receptor. The hormone-receptor complex translocates to the nucleus, binds to specific progesterone response elements (PREs) on DNA, and regulates the transcription of target genes. This leads to the transformation of the estrogen-primed proliferative endometrium into a secretory one, essential for embryo implantation and maintenance of pregnancy.
3. Indications & Uses
- Luteal Phase Support in Assisted Reproductive Technology (ART/IVF cycles)
- Secondary Amenorrhea
- Dysfunctional Uterine Bleeding (DUB)
4. Dosage & Administration
Adult Dosage: Luteal Phase Support (IVF): 50-100 mg IM daily, starting on the day of oocyte retrieval or embryo transfer, continued for up to 10-12 weeks of gestation. Secondary Amenorrhea: 5-10 mg IM daily for 6-8 consecutive days. Dysfunctional Uterine Bleeding: 5-10 mg IM daily for 6 days to stop bleeding; may be followed by cyclic therapy.
Administration: For DEEP INTRAMUSCULAR INJECTION ONLY in the upper outer quadrant of the gluteal muscle. Use a 21-23 gauge, 1.5-inch needle. Aspirate before injection to avoid intravascular administration. Rotate injection sites daily to prevent tissue damage. The oil-based solution is viscous; warm the vial in hands before drawing up to ease administration. Do not administer intravenously or subcutaneously.
5. Side Effects
Common side effects may include:
- Pain, swelling, redness, or itching at injection site
- Drowsiness, somnolence, fatigue
- Breast tenderness or enlargement
- Headache, dizziness
- Mild fluid retention, bloating
- Mood swings, irritability
- Breakthrough bleeding or spotting
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Ketoconazole, Itraconazole, Clarithromycin | Inhibit CYP3A4, increasing progesterone levels and risk of side effects. | Moderate |
| Rifampicin, Carbamazepine, Phenytoin, St. John's Wort | Induce CYP3A4, decreasing progesterone levels and potentially reducing efficacy. | Moderate |
| Other CNS Depressants (Alcohol, Benzodiazepines, Opioids) | Additive sedative effects. | Moderate |
| Enzyme-inducing Antiepileptics (Phenobarbital, Primidone) | Decrease progesterone efficacy. | Moderate |
7. Patient Counselling
- DO rotate injection sites daily (left and right gluteus).
- DO report severe pain, swelling, or redness at the injection site.
- DO inform all your doctors and your IVF specialist that you are on this injection.
- DO use contraception if not undergoing fertility treatment, as progesterone can cause fetal harm if misused.
- DONT administer the injection intravenously or subcutaneously.
- DONT stop the medication abruptly without consulting your doctor, especially during ART cycles.
- DONT drive or operate heavy machinery if you feel drowsy or dizzy.
8. Toxicology & Storage
Overdose: Acute overdose is unlikely with IM administration but could lead to severe extension of pharmacological effects: profound sedation, dizziness, ataxia, nausea, fluid retention, and withdrawal bleeding. Chronic excessive dosing may lead to increased risk of serious side effects like thromboembolism.
Storage: Store below 25°C. Protect from light. Do not freeze. Keep the vial in the outer carton. Once the rubber stopper is punctured, use the vial promptly. Discard any unused solution. Keep out of reach of children.