Nafarelin Acetate

 Action Initially causes synthesis and release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). With continued use (> 4 wk) suppresses secretion of LH and FSH.

 Indications Treatment of endometriosis, central precocious puberty in children of both sexes.

 Contraindications Hypersensitivity to gonadotropin-releasing hormone (GnRH); or GnRH-agonist analogs; undiagnosed abnormal vaginal bleeding; pregnancy; lactation.

 Route/Dosage

Endometriosis

ADULTS: Intranasal 400 mcg/day (200 mcg [1 spray] in 1 nostril in morning and 200 mcg [1 spray] in other nostril in evening. For long-term suppression, 800 mcg/day (1 spray in each nostril bid) may be necessary.

Central Precocious Puberty

CHILDREN: Intranasal 1600 mcg/day (400 mcg [2 sprays] in each nostril in morning and 400 mcg [2 sprays] in each nostril in evening). In some patients 1800 mcg/day (3 sprays in alternating nostrils tid) may be necessary.

 Interactions

None well documented.

 Lab Test Interferences Diagnostic tests of pituitary gonadotropic and gonadal function during treatment and 4 to 8 wk after discontinuation of treatment may be misleading.

 Adverse Reactions

CNS: Headaches; insomnia; depression. DERM: Acne; seborrhea. EENT: Nasal irritation. GU: Vaginal dryness. OTHER: Hot flushes; decreased libido; emotional lability; myalgia; reduced breast size; edema; weight gain; hirsutism; decreased bone density.

 Precautions

Pregnancy: Category X. Lactation: Do not use in lactating women. Bone density loss: May be small loss in bone density during therapy, some of which may not be reversible. Risk is greater in patients who smoke or have osteoporosis and in alcoholics. Intercurrent rhinitis: If patient must use topical nasal decongestant during nafarelin therapy, should be used ³ 2 hr after nafarelin dosing to decrease possibility of reduced absorption. Menstruation: Should stop with effective doses. Noncompliance: Irregular or incomplete doses may result in stimulation of pituitary-gonadal axis. Ovarian cysts: Have occurred in first 2 mo of therapy.

 Administration/Storage

• When treating endometriosis, begin treatment between days 2 and 4 of menstrual cycle.
• Administer intranasally with metered-spray pump. Patient's head should be tilted back slightly.
• If administering > 1 spray per nostril, wait 30 sec between sprays.
• Store container upright at room temperature.
• Protect from light.

 Assessment/Interventions

• Obtain patient history, including drug history and any known allergies.
• Obtain baseline assessments of last menstrual period, pregnancy status in patients with endometriosis, height and weight in patients with central precocious puberty.
• Monitor menstrual cycles.
• Monitor for drug-related hypoestrogenism. Note patient complaints of hot flushes, libido decrease, vaginal dryness, headaches, emotional lability.
• Monitor for signs of androgenism, including acne, myalgia, breast size reduction, edema, weight gain.

 Patient/Family Education

• Caution patient that this medication must not be taken during pregnancy or when pregnancy is possible. Advise patient to use nonhormonal form of birth control while taking this drug.
• Advise patient regarding proper administration techniques and storage information.
• Tell patient to begin treatment between days 2 and 4 of menstrual cycle if being treated for endometriosis.
• Instruct patient not to blow nose and to avoid sneezing immediately after administration.
• Tell patient using topical nasal decongestant to use 2 hr after nafarelin has been administered.
• Advise patient that each bottle contains » 60 sprays and plan refills accordingly.
• Explain side effects of medication and instruct patient to report the following symptoms to physician: Bleeding/menses continues, breakthrough bleeding or adverse/side effects.