Clomiphene is the drug of choice for patients whose ovulation defect is associated with normal levels of estrogen. Generally these are the women who will have a positive Progesterone Challenge Test in that they have a withdrawal bleed after taking progesterone tablets.Tom know more about Clomiphene ,read on .
What is clomiphene and when is it prescribed
Clomiphene is the drug of choice for patients whose ovulation defect is associated with normal levels of estrogen. Generally these are the women who will have a positive Progesterone Challenge Test in that they have a withdrawal bleed after taking progesterone tablets.
How does clomiphene work?
Clomiphene is very similar to Estrogen in its structure, so that feed back receptors in the brain are misled to take up clomiphene instead of estrogen. As a result, the brain is unable to perceive the normal estrogen levels and thinking these are now low, activates the release of F.S.H. from the pituitary. Clomiphene therefore leads to a "knock-on" effect, by stimulating the brain to stimulate the pituitary and so lead to ovarian stimulation and ovulation.
What kinds of patients benefit from clomiphene?
Clomiphene is beneficial in 4 groups of patients:
- Women with amenorrhoea and normal levels of estrogen; e.g. after stopping the contraceptive pill, many women can experience months of delay before their periods become re-established.
- Women with oligomenorrhoea and normal levels of estrogen; e.g. if you are only having 3 periods a year.
- In women who have periods with ovulation but consistently inadequate luteal phases; i.e. your B.B.T. Chart shows that after ovulation the temperature rise is usually maintained for less than 11 days, and the progesterone level on day 21 may also be reduced.
- In women receiving donor insemination; it can be very helpful in regulating ovulation in such cases especially if the cycle is a little erratic.
How is clomiphene administered
Treatment begins within five days of the commencement of menstrual bleeding. A single 50 mg clomiphene tablet has to be taken daily for 5 days. This is regardless of whether the period has been a spontaneous one or resulting from a Progesterone Challenge Test. Ovulation will usually occur 5-13 days after the last tablet of clomiphene. While taking this treatment, it is advisable to maintain a B.B.T. Chart.
The dosage of clomiphene may need to be increased. The dosage can be safely increased at a rate of one tablet per day each cycle until there is evidence of ovulation or until a maximum dose of 200mg (4 tablets) per day is reached. The average patient normally ovulates with a dosage of 50-100 mg per day for 5 days. Once ovulation has been achieved as indicated by a luteal phase of more than 11 days and an adequate day-21 progesterone level, treatment is maintained at the same dosage levels for 6 cycles.
How effective is the clomiphene therapy
80-90% of the patients who take clomiphene therapy should ovulate and 55% of this group should get pregnant. The reason for the difference in percentages between ovulation and pregnancy is that for a number of patients an ovulatory defect is not the only contributory factor in their infertility. If, however, one selects the patients for whom ovulation disorder is the sole cause of infertility, their pregnancy rate is almost as high as the ovulation rate.
There is a 1 in 16 chance (approximately 6%) that clomiphene therpay will result in multiple pregnancies in most cases these will be twins. Patients are not an increased risk of miscarriage. In fact, the miscarriage rate appears to be lower than for the general population. There is no increase in the incidence of abnormalities in the resulting babies.
Does the clomiphene therapy have any side effects
Treatment with clomiphene is very safe. Side effects, if they occur, are mild and only rarely require that treatment be discontinued. The commonest side effect occurring in 10% of women is the symptom of "hot flushes". There is no need to panic. Clomiphene does not trigger menopause. These "hot flushes" are due to the anti-estrogenic effect of clomiphene. Other less frequent symptoms include abdominal distension, breast discomfort, headaches, mild depression and occasional blurring of vision. Clomiphene treatment will have to be discontinued if it results in enlargement of the ovaries. Moderate pelvic pain is a symptom of this condition. Treatment is stopped until the ovaries have returned to normal size.
Is any other test or medication required in addition to clomiphene
It is worth the effort to repeat the post-coital test for patients taking clomiphene, although this test may have been previously normal. This is because clomiphene works by being an anti-estrogen, and sometimes this can result in the mucus becoming much stickier than normal. The additional administration of a short course of a natural estrogen between the last day of clomiphene and the expected time of ovulation can reverse this effect.
If ovulation does not occur even after taking the maximum dosage of clomiphene, or if the luteal phase remains inadequate, human chorionic gonadotrophin (H.C.G.) is given in addition to the clomiphene.
(Note: A number of specialists use a drug very similar to clomiphene called tamoxifen.)