Synarel (Nafarelin Acetate) for Endometriosis

Overview
Synarel is approved by the U.S. Food and Drug Administration (FDA) for the treatment of endometriosis in women 18 years of age and older, according to the prescribing label. It is indicated to relieve symptoms such as pelvic pain and to reduce the size of endometrial lesions. Treatment duration is limited to six months, and it should be started between Days 2 and 4 of the menstrual cycle. Synarel is also known by its drug name, nafarelin acetate.

Synarel belongs to a class of drugs called gonadotropin-releasing hormone (GnRH) agonists. It works by temporarily decreasing the production of estrogen, a hormone that stimulates the growth of endometrial tissue. By lowering estrogen levels, Synarel helps reduce endometriosis symptoms and slows or stops the growth of lesions.

How do I take it?
Prescribing information states that Synarel is administered as a nasal spray. For endometriosis, the recommended starting dose is one spray in one nostril in the morning and one spray in the other nostril in the evening. If menstruation continues after two months, the dose may be increased to two sprays daily in each nostril — one in each nostril in the morning and evening. The treatment should be taken exactly as prescribed by a healthcare provider.

Side effects
Common side effects of Synarel include hot flashes, decreased libido (sex drive), vaginal dryness, headaches, emotional changes (such as mood swings), insomnia, acne, muscle pain, reduction in breast size, nasal irritation, and weight changes.

Rare but serious side effects may include depression, suicidal thoughts or behaviors, pituitary apoplexy (bleeding or impaired blood flow in the pituitary gland), convulsions (seizures), increased intracranial pressure (pseudotumor cerebri), liver injury, and serious cardiovascular problems such as deep vein thrombosis (blood clots), stroke, or heart attack. The drug may also cause bone loss, some of which may not be reversible, especially with extended use.

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Label: Synarel — Nafarelin Acetate Spray, Metered — DailyMed