Clomiphene citrate

Clomiphene Citrate

Clomiphene citrate is a medication commonly used in the field of reproductive medicine to treat infertility in women. It is classified as a selective estrogen receptor modulator (SERM) and is known for its ability to induce ovulation.

Mechanism of Action

Clomiphene citrate works by binding to estrogen receptors in the hypothalamus, a part of the brain that plays a crucial role in regulating the menstrual cycle. By blocking these receptors, clomiphene citrate creates a false sense of low estrogen levels in the body. This stimulates the hypothalamus to release gonadotropin-releasing hormone (GnRH), which in turn prompts the pituitary gland to secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The increase in FSH and LH levels stimulates the ovaries to produce and mature follicles, leading to ovulation.

Indications

Clomiphene citrate is primarily indicated for the treatment of anovulatory infertility, particularly in women with polycystic ovary syndrome (PCOS). It is also used in certain cases of unexplained infertility and in women with irregular menstrual cycles.

Dosage and Administration

Clomiphene citrate is typically administered orally. The standard starting dose is 50 mg per day for five days, beginning on the fifth day of the menstrual cycle. If ovulation does not occur, the dose may be increased in subsequent cycles, up to a maximum of 150 mg per day. Monitoring of ovulation can be done through basal body temperature charts, ovulation predictor kits, or ultrasound.

Side Effects

Common side effects of clomiphene citrate include hot flashes, abdominal discomfort, bloating, and breast tenderness. Less common but more serious side effects include ovarian hyperstimulation syndrome (OHSS) and visual disturbances. Long-term use of clomiphene citrate is not recommended due to the potential risk of ovarian cancer.

Contraindications

Clomiphene citrate is contraindicated in patients with liver disease, abnormal uterine bleeding of undetermined origin, ovarian cysts not due to PCOS, and in those who are pregnant. It should be used with caution in patients with a history of thromboembolic disorders.

Success Rates

The success rate of clomiphene citrate in inducing ovulation is approximately 70-80%, with a pregnancy rate of about 30-40% per cycle. The likelihood of success is higher in women with PCOS compared to those with unexplained infertility.

Alternatives

For patients who do not respond to clomiphene citrate, alternative treatments include letrozole, another ovulation-inducing agent, and gonadotropin injections. In vitro fertilization (IVF) may also be considered for those who do not achieve pregnancy with oral medications.

See Also

• Infertility
• Ovulation induction
• Selective estrogen receptor modulator

References

• Practice Committee of the American Society for Reproductive Medicine. "Use of clomiphene citrate in infertile women: a committee opinion." Fertility and Sterility, 2013.
• Legro RS, et al. "Clomiphene, metformin, or both for infertility in the polycystic ovary syndrome." New England Journal of Medicine, 2007.