Nafarelin is a gonadotropin-releasing hormone agonist

Gonadotropin-releasing hormone agonist

A gonadotropin-releasing hormone agonist is a synthetic peptide modeled after the hypothalamic neurohormone GnRH that interacts with the gonadotropin-releasing hormone receptor to elicit its biologic response, the release of the pituitary hormones FSH and LH.GnRH agonists are pregnancy category...

 (GnRH agonist). By causing constant stimulation of the pituitary

Pituitary gland

In vertebrate anatomy the pituitary gland, or hypophysis, is an endocrine gland about the size of a pea and weighing 0.5 g , in humans. It is a protrusion off the bottom of the hypothalamus at the base of the brain, and rests in a small, bony cavity covered by a dural fold...

, it decreases pituitary secretion of gonadotropins luteinizing hormone

Luteinizing hormone

Luteinizing hormone is a hormone produced by the anterior pituitary gland. In females, an acute rise of LH called the LH surge triggers ovulation and development of the corpus luteum. In males, where LH had also been called interstitial cell-stimulating hormone , it stimulates Leydig cell...

 (LH) and follicle stimulating hormone (FSH). Nafarelin may be used in the treatment of estrogen-dependent conditions (such as endometriosis

Endometriosis

Endometriosis is a gynecological medical condition in which cells from the lining of the uterus appear and flourish outside the uterine cavity, most commonly on the ovaries. The uterine cavity is lined by endometrial cells, which are under the influence of female hormones...

 or uterine fibroids

Uterine fibroids

A uterine fibroid is a benign tumor that originates from the smooth muscle layer and the accompanying connective tissue of the uterus.Fibroids are the most common benign tumors in...

), to treat central precocious puberty

Precocious puberty

As a medical term, precocious puberty describes puberty occurring at an unusually early age. In most of these children, the process is normal in every respect except the unusually early age, and simply represents a variation of normal development. In a minority of children, the early development is...

, and to control ovarian stimulation in IVF

In vitro fertilisation

In vitro fertilisation is a process by which egg cells are fertilised by sperm outside the body: in vitro. IVF is a major treatment in infertility when other methods of assisted reproductive technology have failed...

.

It is normally delivered via a nasal spray.

Nafarelin acetate

Acetate

An acetate is a derivative of acetic acid. This term includes salts and esters, as well as the anion found in solution. Most of the approximately 5 billion kilograms of acetic acid produced annually in industry are used in the production of acetates, which usually take the form of polymers. In...

 is marketed by Searle (now part of Pfizer

Pfizer

Pfizer, Inc. is an American multinational pharmaceutical corporation. The company is based in New York City, New York with its research headquarters in Groton, Connecticut, United States...

) under the brand name Synarel.

Side effects

Side effects of nafarelin are mostly related to the low estrogen state. Side effects include hot flashes, vaginal dryness, headaches, mood changes, and decreased interest in sex. Some patients may experience acne, muscle pain, reduced breast size, and irritation of the tissue inside the nose. These side effects should disappear after stopping the medication.