Infertility Treatments: Injectable Drugs
Melissa Conrad Stöppler, MD
Roxanne Dryden-Edwards, MD
Women undergoing infertility treatment are all too familiar with the need to
administer injections, whether subcutaneous (beneath the skin) or intramuscular.
Although the commonly used fertility drug clomiphene (Clomid) is taken in pill
form, a great many of the drugs required for women being treated for infertility
necessitate getting a shot- typically, many shots – over a period of days to
weeks. Depending upon her precise diagnosis and medical history, a woman may
take one or several of these injectable fertility treatments.
The injectable drugs for infertility are hormonal treatments, all designed to
regulate and stimulate the production of hormones or to trigger ovulation. There
are subtle differences in the drugs and their mechanisms of action, although
they are all used to promote fertility in some way.
Commonly used injectable drugs for infertility treatments include:
- hMG, or human menopausal gonadotropin (Pergonal,
Repronex, and Metrodin): This drug is made up of two human hormones,
follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Gonadotropins
are commonly administered to women undergoing assisted reproduction technology
treatments with the goal of stimulating the ovaries to produce multiple
follicles (eggs) during one cycle. FSH and LH are the hormones that normally
regulate the ovarian cycle and stimulate egg development and ovulation, and
injections of this drug typically are given daily for 7 to 12 days in the first
half of the menstrual cycle.
- FSH, or follicle stimulating hormone,
may also be given on its own for the same purpose and in a similar manner as hMG.
Brand names for FSH include Follistim, Fertinex, Bravelle, Menopur, and Gonal-F.
- Human chorionic gonadotropin, or hCG (Pregnyl,
Novarel, Ovidrel, and Profasi) is a hormone used to trigger release of the eggs
from the follicles (ovulation). This is given in combination with other
fertility drugs that stimulate follicle production and is administered at a
precise time during the menstrual cycle, based upon the results of blood tests
and ultrasound examinations. This is the same hormone that is produced by
placenta during pregnancy and is measured in pregnancy tests.
- Gonadotropin Releasing Hormone
Agonists, or GnRH agonists (Lupron, Zoladex, and Synarel) work by shutting down
the body's production of ovarian hormones such as FSH and LH, lowering the
body's estrogen levels. Normally in the body, GnRH is produced by the pituitary
gland and stimulates the ovaries to produce hormones. When GnRH agonist is taken
as a medication, there is an initial increase in hormone production and then a
decline as the body senses that too much hormone is being made. Shutting down
the normal hormone production by the ovaries allows for the precise control of
egg development during a fertility treatment cycle. For example, a woman
undergoing IVF may start taking this drug in the second half of her menstrual
cycle, prior to the cycle in which she will attempt IVF. After the body's
natural hormone production is shut down, gonadotropin drugs (see above) will be
given to stimulate follicle production. Another advantage of GnRH agonists is
that the body's natural production of LH, which triggers ovulation, is shut off,
meaning that ovulation cannot occur prematurely and will not occur until the hCG
injection (see above) is given.
- Gonadotropin Releasing Hormone
Antagonist or GnRH antagonists (Antagon, Ganirelix, and Cetrotide) have a
similar effect as GnRH agonists, but rather than initially stimulating and then
down-regulating ovarian hormone production, GnRH antagonists work by immediately
blocking the release of ovarian hormones. Typically, fewer injections of GnRH
antagonists are required because of their stronger effect in reducing ovarian
REFERENCE: WebMD.com. Fertility Drugs.Last Editorial Review: 3/28/2013 7:09:56 PM