Ganirelix acetate is a synthetic decapeptide and a potent, competitive antagonist of the gonadotropin-releasing hormone (GnRH) receptor. It is used in controlled ovarian stimulation (COS) protocols for assisted reproductive technology (ART) to prevent premature luteinizing hormone (LH) surges, thereby preventing premature ovulation and allowing for proper follicular maturation and oocyte retrieval.
Adult: 0.25 mg (250 micrograms) administered subcutaneously once daily. Initiation: Start on Day 6 of ovarian stimulation with FSH/hMG (or when the leading follicle reaches approximately 12-14 mm in diameter as per clinic protocol). Continue daily until the day of hCG (human chorionic gonadotropin) administration for final oocyte maturation.
Note: For subcutaneous use only. Administer in the lower abdomen (alternating sites), at least 1 inch away from the navel. Ensure the solution is clear and colorless. Use pre-filled syringe or reconstituted vial as per instructions. Rotate injection sites daily. Administer at approximately the same time each day.
Ganirelix competitively blocks the pituitary GnRH receptors. This immediate blockade inhibits the secretion of gonadotropins—Luteinizing Hormone (LH) and Follicle-Stimulating Hormone (FSH)—from the anterior pituitary. By suppressing the mid-cycle LH surge, it prevents premature luteinization and ovulation during controlled ovarian stimulation, allowing for the continued growth of multiple follicles under exogenous gonadotropin therapy.
Pregnancy: **Category X.** Contraindicated during pregnancy. It is used only in the pre-ovulatory phase of an ART cycle to prevent LH surge. If pregnancy is confirmed, administration must be stopped immediately. No teratogenic risk is expected from short-term pre-conception exposure.
Driving: No known effects. However, patients should be cautioned about potential dizziness or fatigue.
| Other GnRH analogs (Agonists like Leuprolide, Buserelin) | Pharmacological antagonism; concurrent use is contraindicated. | Major |
| Gonadotropins (FSH, hMG, hCG) | Used therapeutically in sequence. Ganirelix is used to prevent premature LH surge during gonadotropin stimulation. No adverse pharmacokinetic interaction. | Moderate (Therapeutic sequence) |
| Oral Contraceptives, Estrogens, Androgens | May interfere with the efficacy of the controlled ovarian stimulation protocol. Should be discontinued prior to starting ART cycle. | Major |
| Glucocorticoids | High doses may interfere with the hypothalamic-pituitary-ovarian axis. Use with caution. | Moderate |
Same composition (Ganirelix (0.25mg)), different brands: