Fostimon works by mimicking the action of endogenous FSH, a hormone produced by the pituitary gland. Its mechanism of action includes:

1. Ovarian Follicle Stimulation:
   • In women, FSH binds to receptors on ovarian granulosa cells, promoting the growth and maturation of ovarian follicles.
   • This leads to the development of multiple follicles, increasing the chances of successful ovulation and fertilization.
2. Estrogen Production:
   • FSH stimulates granulosa cells to produce estrogen, which prepares the endometrium (uterine lining) for embryo implantation.
3. Spermatogenesis in Men:
   • In men, FSH binds to receptors on Sertoli cells in the testes, supporting the production and maturation of sperm.

Fostimon is primarily used for the following conditions:

1. Female Infertility:
   • Ovulation Induction: Used to stimulate follicular development in women with anovulatory infertility, such as polycystic ovary syndrome (PCOS).
   • Assisted Reproductive Technology (ART): Used in IVF and intracytoplasmic sperm injection (ICSI) to induce multiple follicular development.
2. Male Infertility (Off-Label):
   • Stimulates spermatogenesis in men with hypogonadotropic hypogonadism (low FSH levels).
3. Unexplained Infertility:
   • May be used as part of a comprehensive fertility treatment plan.

The dosage of Fostimon varies depending on the condition being treated and the patient’s response. Always follow the prescribing physician’s instructions.

Common Dosages:

• Ovulation Induction:
  • Initial dose: 75–150 IU subcutaneously (SC) or intramuscularly (IM) daily, starting on day 2–3 of the menstrual cycle.
  • Dose adjustments: The dose may be increased by 37.5–75 IU every 7–14 days based on follicular growth and estrogen levels.
  • Maximum dose: 450 IU daily.
• ART (IVF/ICSI):
  • Initial dose: 150–225 IU SC/IM daily, starting on day 2–3 of the menstrual cycle.
  • Dose adjustments: Tailored based on ovarian response, monitored via ultrasound and hormone levels.
• Male Infertility (Off-Label):
  • Dosage varies; typically 75–150 IU SC/IM 2–3 times weekly, combined with human chorionic gonadotropin (hCG).

Administration Tips:

• Administer via SC or IM injection. Rotate injection sites to minimize tissue irritation.
• For fertility treatments, regular monitoring (ultrasound and hormone levels) is essential to prevent complications like ovarian hyperstimulation syndrome (OHSS).

Fostimon is generally well-tolerated, but some patients may experience side effects:

Common Side Effects:

• Injection site reactions (pain, redness, swelling)
• Mild ovarian enlargement
• Abdominal discomfort or bloating
• Headache
• Nausea

Rare but Serious Side Effects:

• Ovarian Hyperstimulation Syndrome (OHSS): A potentially life-threatening condition characterized by rapid ovarian enlargement, ascites, and electrolyte imbalances.
• Thromboembolic Events: Increased risk of blood clots, stroke, or pulmonary embolism.
• Multiple Pregnancies: Increased risk of twins or higher-order multiples.
• Allergic Reactions: Rash, itching, or anaphylaxis (rare).

If severe side effects occur, discontinue use and seek immediate medical attention.

Before using Fostimon, inform your healthcare provider if you have:

• Ovarian cysts or polycystic ovary syndrome (PCOS)
• History of blood clots or thromboembolism
• Thyroid or adrenal gland disorders
• Pituitary or hypothalamic tumors
• Allergies to FSH or any component of the formulation

Special Populations:

• Pregnancy: Fostimon is contraindicated during pregnancy unless used as part of fertility treatment.
• Breastfeeding: Safety during breastfeeding is not established.
• Pediatric Use: Not indicated for use in children.

Fostimon may interact with other medications, altering their effects:

1. Gonadotropin-Releasing Hormone (GnRH) Agonists/Antagonists:
   • Used in ART to prevent premature ovulation.
2. Human Chorionic Gonadotropin (hCG):
   • Often used in combination with Fostimon to trigger ovulation.
3. Corticosteroids:
   • May reduce the therapeutic effect of Fostimon.
4. Hormonal Contraceptives:
   • May interfere with ovulation induction.
5. Anticoagulants:
   • Fostimon may enhance the risk of bleeding when combined with blood thinners like warfarin.

Generic Names in Pharmacy

• Urofollitropin (the active ingredient in Fostimon)
• Follicle-stimulating hormone (FSH)