Examples
| Generic Name | Brand Name |
|---|
| clomiphene citrate | Clomid, Milophene, Serophene |
How It Works
Clomiphene stimulates the release of
hormones needed to cause
ovulation.
Clomiphene therapy is
typically used for 5 consecutive days early in the
menstrual cycle, for 3 to 6 monthly cycles. It may
take several cycles to find the right dose to stimulate ovulation. After that
dose is determined, a woman will take the drug for at least 3 more cycles. If
she does not become pregnant after 6 cycles, it is unlikely that further
clomiphene treatment will be successful.
Why It Is Used
For women.
Clomiphene may be prescribed to:
- Stimulate ovulation in a woman who does not
ovulate or who ovulates irregularly. Her
estrogen levels and
pituitary gland function must be normal, and her male
partner must be diagnosed as fertile.
- Perform a clomiphene challenge test, which is sometimes used to evaluate
a woman's ovulation and egg quality (ovarian reserve). When given early in a
woman's menstrual cycle for 5 days, clomiphene elevates a woman's
follicle-stimulating hormone (FSH) level. On the next day, an FSH blood level
that has dropped back to normal is a sign of a normal ovarian reserve and
ovulation. An elevated FSH is a sign of low ovarian reserve. Women with a
diminished ovarian reserve can use donor eggs, which greatly improves their
chances of giving birth to a healthy child.
- Stimulate the
development of multiple eggs for use with
assisted reproductive technology, such as in vitro
fertilization (IVF) or gamete intrafallopian transfer
(GIFT).
- Regulate ovulation in a woman who ovulates irregularly
and/or is going to have
intrauterine insemination or artificial
insemination.
Clomiphene is sometimes used together with other medicines
and infertility treatments.
Before trying clomiphene, women with
polycystic ovary syndrome (PCOS) who are overweight
are advised to lower their
body mass index (BMI) with diet and exercise. Reaching
a healthy weight can restart ovulation.1 If that isn't
successful, using medicine to correct
insulin metabolism may start ovulation. If not, a
combination of medicines may help stimulate ovulation.
For
men. Clomiphene may be used to treat low sperm counts
(oligospermia).
How Well It Works
Unexplained
infertility. There is limited evidence that clomiphene makes pregnancy
more likely for couples with unexplained infertility.2
Clomiphene may be most effective when it is used to generate multiple eggs
before an insemination procedure.
Infrequent or no
ovulation. Of women whose infertility is caused only by absent or
infrequent ovulation, with clomiphene treatment approximately 80% will ovulate.
And within 9 cycles of treatment, 70% to 75% will become pregnant. Experts used
to think miscarriage rates were slightly higher in women who became pregnant
using clomiphene, but recent studies have not shown this to be true.3
Polycystic ovary
syndrome. Clomiphene alone may not be an effective treatment for most
women with polycystic ovary syndrome (PCOS) and severe
insulin resistance, which is closely linked to
obesity. Women with PCOS who are overweight often begin ovulating when they
reduce their body mass index (BMI) with diet and exercise.
Side Effects
Side effects of clomiphene
include:
- Ovarian
hyperstimulation, ranging from mild, with enlarged ovaries and abdominal
discomfort; to moderate, additionally causing nausea, vomiting, or shortness of
breath; to severe and life-threatening.
- Hot
flashes.
- Irritability.
- Nausea, abdominal
pain.
- Headaches.
- Thick cervical mucus, which sperm
cannot travel through. This can be reversed with medicine or bypassed with
intrauterine insemination.
- Breast tenderness.
- Blurred
vision.
- Hair loss (very rare).
Women who become pregnant after clomiphene therapy have an
approximately 5% to 8% chance of multiple pregnancy.3
This compares to a 1% to 2% chance in the general North American and European
population.2 Multiples resulting from clomiphene
treatment are almost exclusively twins. Triplets are rare.3
Miscarriage risk?
In some studies,
miscarriage rates are slightly higher in women who
become pregnant using clomiphene. It is not clear if this is related to an
early hormonal effect on the egg or to preexisting conditions such as age or
polycystic ovary syndrome, which are found more often in women who take
clomiphene. Other studies have not shown an increased miscarriage rate.3
Clomiphene has not been observed to harm the
fetus.3
Ovarian cancer risk?
A 1994 study has suggested
that 12 or more cycles of clomiphene increase the risk of ovarian tumors.
Studies since then have found no link between clomiphene and ovarian
cancer.2 The issue is still being studied. Few
specialists recommend long-term use of clomiphene.
See Drug Reference for a full list of side effects.
(Drug Reference is not available in all systems.)
What To Think About
Many women try clomiphene therapy
before beginning a series of infertility tests. But most doctors recommend a
careful medical history, physical exam, and semen analysis before beginning
clomiphene. If your pituitary,
thyroid, and
adrenal function have been checked, you have no signs
of
endometriosis, and your partner's fertility has been
confirmed, clomiphene is considered a safe and simple option.3
Most women who become pregnant by using
clomiphene do so within 3 cycles, and the majority become pregnant within 6
cycles of clomiphene use.1 Prolonged treatment with
clomiphene is usually not helpful. After 3 to 6 cycles, further evaluation or a
change in treatment plan is recommended.3
Make sure your doctor knows of any abnormal vaginal bleeding or history
of problem
ovarian cysts before prescribing clomiphene for you.
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