Norelgestromin

Norelgestromin.svg

Norelgestromin is a progestin used in hormonal contraception. It is the active metabolite of norgestimate, a third-generation progestin. Norelgestromin is commonly used in combination with an estrogen in transdermal contraceptive patches.

Pharmacology

Norelgestromin works by inhibiting ovulation, altering the cervical mucus to prevent sperm penetration, and changing the endometrium to prevent implantation. It binds to progesterone receptors in the body, exerting its effects primarily on the reproductive system.

Medical Uses

Norelgestromin is primarily used in contraception to prevent pregnancy. It is available in combination with ethinylestradiol in a transdermal patch, which is applied to the skin and releases hormones over a period of time.

Side Effects

Common side effects of norelgestromin include nausea, headache, breast tenderness, and irregular bleeding. Serious side effects can include venous thromboembolism, stroke, and myocardial infarction, particularly in women who smoke and are over the age of 35.

Contraindications

Norelgestromin should not be used in women with a history of thromboembolic disorders, breast cancer, liver disease, or uncontrolled hypertension. It is also contraindicated in women who are pregnant or have undiagnosed vaginal bleeding.

Mechanism of Action

Norelgestromin acts by mimicking the effects of natural progesterone. It suppresses the release of gonadotropins from the pituitary gland, which prevents the maturation and release of ova from the ovaries. Additionally, it thickens the cervical mucus, making it difficult for sperm to enter the uterus.

Formulations

Norelgestromin is available in a transdermal patch form, which is marketed under various brand names. The patch is typically worn on the skin for one week at a time, with a new patch applied each week for three weeks, followed by a patch-free week.

See Also

• Progestin
• Hormonal contraception
• Transdermal patch
• Ethinylestradiol
• Norgestimate