Gonal-F (follitropin alfa, recombinant)

Follitropin alfa and follitropin beta are recombinant human follicle stimulating hormones (hFSH) with 2 glycoprotein subunits (alpha and beta) that are identical to those of hFSH.

Follitropin alfa and beta (recombinant) are human follicle-stimulating hormones (hFSH), prepared using recombinant DNA technology, with 2 glycoprotein subunits (alpha and beta) that are identical to those of hFSH. Follicle-stimulating hormone, the active component of follitropin products, is necessary for normal follicular growth and maturation, as well as gonadal steroid production. The level of follicle-stimulating hormone in women is critical for the onset and duration of follicular development, and consequently for the timing and number of follicles that reach maturity.

In women who do not have primary ovarian failure, these products stimulate follicular growth within the ovaries. Once monitoring of the woman suggests that appropriate follicular development has occurred, human chorionic gonadotropin (hCG) is administered after follitropin to assist with follicle maturation, resumption of meiosis, and rupture of the follicle in the absence of an endogenous luteinizing hormone surge. When administered along with hCG in men with hypogonadotropic hypogonadism, follitropin stimulates spermatogenesis; FSH is the pituitary hormone responsible for spermatogenesis.

Following subcutaneous administration of follitropin alfa for injection (Gonal-F(R)) in healthy female volunteers, absolute bioavailability was 66 +- 39%. Following administration in healthy female and male volunteers, the time to peak serum concentration was 15 and 20 hours, respectively, after a single dose and 8 and 10.7 hours, respectively, after multiple doses. Terminal elimination half-lives were 24 or 41 hours in healthy female or male volunteers following a single dose, 24 or 32 hours in healthy female or male volunteers following multiple doses, and 32 hours in female in vitro fertilization/embryo transfer patients.

Absorption of follitropin alfa for injection (Gonal-F(R)) decreases as body mass index increases.

Following subcutaneous administration of a single 300 IU dose of follitropin alfa injection (Gonal-F(R) RFF Redi-ject(R)) in 21 premenopausal healthy female volunteers who were pituitary down-regulated with a gonadotropin-releasing hormone agonist, the time to peak serum concentration was 15.5 hours and the elimination half-life was 53 hours. The absorption rate after subcutaneous administration is slower than the elimination rate; thus, pharmacokinetics are absorption rate-limited. Human tissue or organ distribution and follicle-stimulating hormone metabolism and excretion have not been studied following administration of follitropin alfa injection in humans.

Following subcutaneous administration of a single 150 IU dose of follitropin beta injection (Follistim(R) AQ) in 20 healthy female volunteers, the time to peak serum concentration was 12.9 hours and the elimination half-life was 33.4 hours. After subcutaneous administration of a single 300 mg dose in healthy pituitary-suppressed women, 77.8% of the dose was absorbed. After administration of multiple doses (75, 150, or 225 IU for 7 days) in healthy, pituitary-suppressed female patients, steady-state concentrations of follicle-stimulating hormone were reached with all doses after 5 days.

No pharmacokinetic studies have been conducted using follitropin beta injection cartridge (Follistim(R) AQ) in men. The recombinant follicle-stimulating hormone in this product is biochemically similar to urinary follicle-stimulating hormone and thus is expected to be metabolized the same way.

USES: This medication contains follicle-stimulating hormone (FSH) and is used to treat certain fertility problems in women and men. In women, follitropin alfa helps stimulate healthy ovaries to produce eggs. This medication is usually used in combination with another hormone (hCG) to bring about the growth and release of a mature egg (ovulation).

In men, this medication helps stimulate healthy testes to produce sperm. It is also used in combination with hCG. This medication is not recommended for women whose ovaries no longer make eggs properly (primary ovarian failure) or for men whose testes no longer make sperm properly (primary testicular failure).

Generic name: follitropin alfa, recombinant
Pronunciation: (FOL-i-TROE-pin AL-fa)
Drug class: Follicle-Stimulating Hormone (FSH)
Therapeutic class: Endocrine

The following indications are listed for Gonal-F:

• Follicle Stimulation For Assisted Fertilization Procedure
• Hypogonadotropic Hypogonadism
• Infertility Associated With Anovulation

Also known as: Infertility Associated With Ovulation Failure, Multifollicular Development For Assisted Reproductive Technologies.