There are great inter- and intra-individual variations in the response of the ovaries to exogenous gonadotrophins. This makes it impossible to set a uniform dosage scheme. The dosage should, therefore, be adjusted individually depending on the ovarian response. This requires ultrasonography and monitoring of oestradiol levels. There should be consideration to minimize the risk of unwanted ovarian hyperstimulation. FSH can be given either alone, or in combination with a GnRH analogue to prevent premature luteinisation. In the latter case, especially when using a GnRH agonist, a higher total treatment dose of FSH may be required to achieve an adequate follicular response. Clinical experience with FSH is based on up to three treatment cycles in both indications. Overall experience with IVF indicates that in general the treatment success rate remains stable during the first four attempts and gradually declines thereafter.
Ovulation Induction in Women: Starting daily dose of 50 international units (IU) of FSH is administered subcutaneously or intramuscularly for at least the first 7 days. The dose is increased by 25 or 50 international units (IU) at weekly intervals until follicular growth and/or serum oestradiol levels indicate an adequate response. When an acceptable pre-ovulatory state is achieved, final oocyte maturation is achieved with 5000 to 10,000 international units (IU) of human chorionic gonadotropin (HCG). The woman and her partner should have intercourse daily, beginning on the day prior to the administration of HCG and until ovulation becomes apparent.
Assisted Reproductive Technology (ART): In Women: Starting dose of 150 to 225 international units (IU) of FSH is administered intramuscularly for at least the first 4 days of treatment. Subsequent doses are adjusted based upon ovarian response as determined by ultrasound evaluation of follicular growth and serum oestradiol levels. Final oocyte maturation is induced with a dose of 5000-10,000 international units of HCG. Oocyte (egg) retrieval is performed 34 to 36 hours later.
Polycystic Ovarian Syndrome (PCOS): FSH injections are therefore given each morning as an intramuscular injection. It is best to start with the lowest dose of FSH per day (using 50 IU per day). These doses are used for 4 to 6 days at a time. The ovarian response is determined by measuring oestrogen levels in the blood. When the oestrogen begins to rise, the FSH is successfully growing an egg or eggs. If there is no response to a dose of FSH in 5-6 days of injections, the dose will be increased. The normal dose increments are 75 units, 112 units, 150 units and 225 units per day. Most patients respond with 75 to 150 IU per day. However, it is very important that increments are made only cautiously.
Dosage in Male: Induction of Spermatogenesis in Men: Pre-treatment with HCG alone (1500 international units (IU) twice weekly) is required. If serum testosterone levels have not normalized after 8 weeks of HCG treatment, the dose may be increased to 3000 international units (IU) twice a week. After normalization of serum testosterone levels, administer 450 international units (IU) per week (225 international units twice weekly or 150 international units (IU) three times weekly) of FSH subcutaneously with the same pre-treatment HCG dose used to normalize testosterone level.
Administration
To prevent painful injections and minimize leakage from the injection site, FSH should be slowly administered intramuscularly or subcutaneously. The subcutaneous injection site should be alternated to prevent lipoatrophy. Any unused solution should be discarded. Subcutaneous injection of FSH may be carried out by the patient or partner, provided that proper instructions are given by the physician. Self-administration of FSH should only be performed by patients who are well-motivated, adequately trained, and have access to expert advice.