rFSH

Indications

Recombinant Follicle Stimulating Hormone (rFSH, also called follitropin) is a fertility hormone. In women it is used to stimulate the ovaries to develop eggs, either to bring on ovulation (for example in polycystic ovary syndrome when other treatment has failed) or to produce several eggs for IVF and similar treatments. In men with low hormone levels from the pituitary gland, it is used with hCG to help sperm production.

How It Works

FSH is a natural hormone made by the pituitary gland. It tells the ovaries to grow follicles (the small sacs that hold eggs) and, in men, helps the testes make sperm. rFSH is made in the laboratory and is identical to the natural hormone, so it gives a controlled, measured dose of this signal.

Dosage and Administration

rFSH is given as an injection under the skin, usually from a pen or prefilled syringe, once a day or as directed. The dose is set and adjusted by a fertility specialist using ultrasound scans and blood tests, so it must be used exactly as prescribed. A nurse will show how to inject at home.

Interactions

• It is often used together with other fertility medicines such as hCG, GnRH agonists or antagonists and Clomifene; the specialist plans these together, and the dose of rFSH may need to change.
• No other important drug interactions are known, but tell the doctor about all medicines and supplements.

Contraindications

• Allergy to follitropin or any ingredient.
• Tumours of the ovary, breast, uterus, testis, pituitary gland or hypothalamus.
• Unexplained vaginal bleeding, ovarian enlargement or cysts not due to polycystic ovary syndrome.
• Primary ovarian or testicular failure (when the ovaries or testes cannot respond).
• Conditions that make pregnancy unsafe, such as fibroids or uterine malformations that prevent pregnancy, and existing pregnancy.

Side Effects

Common effects include pain, redness or bruising at the injection site, headache, bloating, mild pelvic or stomach pain, nausea and breast tenderness. Ovarian hyperstimulation syndrome (OHSS) can occur, where the ovaries swell and fluid collects in the abdomen. Multiple pregnancy (twins or more), ectopic pregnancy and miscarriage are more likely with fertility treatment.

Get urgent medical help if there is severe stomach pain or swelling, rapid weight gain, vomiting, very little urine, shortness of breath, leg pain or swelling, or chest pain.

Pregnancy and Lactation

rFSH is not used during pregnancy or breastfeeding. Treatment stops once pregnancy is confirmed.

Precautions and Warnings

• Treatment must be monitored closely with scans and blood tests to lower the risk of OHSS and multiple pregnancy.
• Thyroid, adrenal or pituitary problems should be treated before starting.
• Tell the doctor about any history of blood clots, as fertility treatment can raise this risk.

Overdose

Too much rFSH can overstimulate the ovaries and cause OHSS. Contact the fertility clinic if a larger dose was injected by mistake.

Therapeutic Class

Gonadotropin (fertility hormone).

Storage

Store in a refrigerator at 2 to 8°C; do not freeze. Some pens may be kept at room temperature for a limited time as stated on the pack. Protect from light and keep out of the reach of children.