Trade Names:Synarel- Nasal solution 2 mg/mL (as nafarelin base)
Initially causes synthesis and release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). With continued use (more than 4 wk) suppresses secretion of LH and FSH.
Nafarelin acetate is rapidly absorbed into system circulation after intranasal administration. T max is 10 to 40 min, C max is 0.6 to 1.8 ng/mL, and serum bioavailability is 2.8%.
Plasma protein binding is 80%.
Nafarelin acetate is eliminated in urine (3% as unchanged) and feces. Serum t 1/ 2 is about 3 h (adults), 2.5 h (children), and 85.5 h (metabolites).
Treatment of endometriosis, central precocious puberty in children of both sexes.
Hypersensitivity to gonadotropin-releasing hormone (GnRH); or GnRH-agonist analogs; undiagnosed abnormal vaginal bleeding; pregnancy; lactation.
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 twice daily) may be necessary.Central Precocious PubertyChildren
Intranasal 1,600 mcg/day (400 mcg [2 sprays] in each nostril in morning and 400 mcg [2 sprays] in each nostril in evening). In some patients 1,800 mcg/day (3 sprays in alternating nostrils 3 times daily) may be necessary.
Store container upright at controlled room temperature (59° to 86°F). Protect from light.
None well documented.
Diagnostic tests of pituitary gonadotropic and gonadal function during treatment and 4 to 8 wk after discontinuation of treatment may be misleading.
Headaches; insomnia; depression.
Hot flushes; decreased libido; emotional lability; myalgia; reduced breast size; edema; weight gain; hirsutism; decreased bone density.
Category X .
Do not use in lactating women.
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.
If patient must use topical nasal decongestant during nafarelin therapy, should be used at least 2 h after nafarelin dosing to decrease possibility of reduced absorption.
Should stop with effective doses.
Irregular or incomplete doses may result in stimulation of pituitary-gonadal axis.
Have occurred in first 2 mo of therapy.
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