Introduction
Clomiphene is a drug that is mainly taken by women with unfulfilled desire to have children. The active ingredient is a so-called oestrogen receptor antagonist, which triggers ovulation. Clomiphene can easily be taken in tablet form and is therefore prescribed as the treatment of choice for infertility.
Effect
Clomiphene is a drug from the group of so-called selective estrogen receptor modulators (SERM). The active ingredient contained in the tablets is clomifen dihyrocitrate. This is a hormone preparation which acts as an oestrogen receptor antagonist (also called anti-oestrogens).
Clomifen works by preventing the hormone estradiol from binding to the corresponding estrogen receptors in the hypothalamus and pituitary gland, both of which are located in the brain. Due to a complex feedback mechanism, the hypothalamus thereby produces increased amounts of the hormone GnRH (gonadotropin-releasing hormone), which in turn leads to a massive release of LH (luteinizing hormone) and FSH (follicle-stimulating hormone) from the pituitary gland. The increased release of LH and FSH promotes the maturation of the egg cells in the ovary and finally leads to ovulation. In this way clomiphene induces ovulation. The ovulation in turn is the prerequisite for the mature egg to be fertilised and for an embryo to develop.
Indications
Clomiphene triggers ovulation after ingestion and is therefore used in women who are infertile (sterile) due to a malfunction of the fallopian tubes. The indication for taking clomiphene is therefore a desire to have children in women whose fallopian tubes are not functioning properly. A precondition for clomiphene to lead to a successful treatment is that the sterility is caused by hormones.
This means that the women to be treated are infertile because they produce too few sex hormones or pituitary hormones. Normally ovulation is controlled by hormones. During the cycle, a woman’s body produces various hormones (GnRH, LH, FSH, oestrogen and progesterone) which stimulate the ovaries, lead to follicle maturation and finally to ovulation.
The mature egg cell is ejected from the ovary and absorbed by the fallopian tube. Fertilisation by a sperm can then take place in the fallopian tube. If the concentration of these hormones is reduced, ovulation either remains or occurs only rarely, which is why these women cannot conceive children. Egg cell maturation disorders can also be treated with clomiphene.
Taking clomiphene
Clomiphene should be taken exactly as directed by the treating physician. Clomifen is characterized above all by its ease of use. In contrast to other hormone preparations, which often have to be administered in the form of injections, Clomifen can simply be taken orally as a tablet.
Treatment with the hormone preparation begins in the first week of the cycle. The start of menstrual bleeding in a woman marks the beginning of a new cycle. Taking Clomifen begins either on the 2nd or 5th day of the cycle and is then continued for five days (i.e. until the 7th or 9th day of the cycle).
If a normal cycle with ovulation does not occur after an initial dose of clomiphene, the intake can be continued for several cycles (i.e. months). In such cases, the dose may be increased to 100-150 mg (i.e. two to three tablets daily) after consultation with the doctor. However, a maximum duration of six months and a total dose of 750 mg clomiphene (equivalent to 15 tablets) per cycle should not be exceeded.
After three consecutive cycles of clomiphene at the latest, a break in intake of at least two months must also be observed. If pregnancy occurs, the tablets must be discontinued immediately, otherwise the embryo may be damaged or spontaneous abortion may occur. Clomifen is administered orally on the 2nd or 5th day of the cycle (i.e. two or five days after the onset of menstrual bleeding).
The dosage is 25 mg or 50 mg per tablet. The drug is taken five days in a row in a cycle. If after an initial cycle the desired effect (i.e. a normal cycle with ovulation) does not occur, the doctor may consider increasing the dosage to 100-150 mg daily (equivalent to 2-3 tablets). The exact dosage of Clomifen is determined beforehand by the treating gynaecologist.
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