Clomifen

Clomifen, also known as clomiphene or clomiphene citrate, is a nonsteroidal selective estrogen receptor modulator (SERM) used primarily to treat infertility due to anovulation. It is also employed in men for certain forms of hypogonadism. Clomifen is supplied as an oral medication and is usually given in cycles under medical supervision.

Mechanism of action iscentred on estrogen receptor modulation. In the hypothalamus, clomifen acts as an antagonist to estrogen receptors, reducing the negative feedback of circulating estrogens. This leads to increased release of gonadotropin-releasing hormone (GnRH) and subsequent rise in follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The rise in FSH and LH promotes ovarian follicle development and ovulation. In other tissues, clomifen can act as a partial agonist or antagonist, depending on tissue type and hormonal context.

Indications and use: The primary indication is infertility due to anovulation, including polycystic ovary syndrome (PCOS). It may be used in certain assisted reproductive technology protocols and, in some cases, for male infertility associated with hypogonadism by boosting endogenous gonadotropin production.

Adverse effects: Common effects include hot flashes, nausea, breast tenderness, headaches, and mood changes. Visual disturbances can occur and, although rare, may require discontinuation. There is a risk of ovarian hyperstimulation and multiple pregnancies in women. Other potential effects include abdominal discomfort and changes in menstrual bleeding. Liver function abnormalities are rare.

Contraindications and cautions: It is contraindicated in pregnancy and in individuals with known liver disease or unexplained vaginal bleeding. Use should be under medical supervision with appropriate monitoring for efficacy and adverse effects.