NAFARELIN ACETATE
| NAFARELIN ACETATE (na-fa're-lin) Synarel Classifications: hormone; gonadotropin-releasing hormone analog; Therapeutic: gonadotropin-releasing hormone analog Prototype: Leuprolide Pregnancy Category: X |
Availability
0.2 mg/spray solution
Action
Potent agonist analog of gonadotropin-releasing hormone (GnRH). Inhibits pituitary gonadotropin secretion of LH and FSH.
Therapeutic Effect
Decrease in serum estradiol or testosterone concentrations results in the quiescence of tissues and functions that depend on LH and FSH.
Uses
Endometriosis and precocious puberty.
Unlabeled Uses
Uterine leiomyomas, benign prostatic hypertrophy.
Contraindications
Hypersensitivity to GnRH or GnRH agonist analog; undiagnosed abnormal vaginal bleeding; pregnancy (category X), lactation.
Cautious Use
Polycystic ovarian disease; osteoporosis.
Route & Dosage
| Endometriosis Adult: Inhalation 2 inhalations/d (200 mcg/inhalation), one in each nostril, begin between days 2 and 4 of menstrual cycle; in patients with persistent regular menstruation after 2 mo of therapy, may increase to 800 mcg/d as 2 inhalations (one in each nostril) b.i.d.; do not exceed 6 mo of treatment Precocious Puberty Child: Inhalation 800–1200 mcg/d divided q8–12h |
Administration
Inhalation- Withhold any topical nasal decongestant, if being used, until at least 30 min after nafarelin administration.
- Store at 15°–30° C (59°–86° F); protect from light.
Adverse Effects (≥1%)
GI: Bloating, abdominal cramps, weight gain, nausea. Endocrine: Hot flashes, anovulation, amenorrhea, vaginal dryness, galactorrhea. Metabolic: Decreased bone mineral content (reversible). CNS: Transient headache, inertia, mild depression, moodiness, fatigue. Respiratory: Nasal irritation. Urogenital: Impotence, decreased libido, dyspareunia.Diagnostic Test Interference
Increased alkaline phosphatase; marked increase in estradiol in first 2 wk, then decrease to below baseline; decreased FSH and LH levels; decreased testosterone levels.
Interactions
Drug: No clinically significant interactions established.Pharmacokinetics
Absorption: 21% absorbed from nasal mucosa. Onset: 4 wk. Peak: 12 wk. Duration: 30–50 d after discontinuing drug. Distribution: 78–84% bound to plasma proteins; crosses placenta. Metabolism: Hydrolyzed in kidney. Elimination: 44–55% in urine over 7 d, 19–44% in feces. Half-Life: 2.7 h.Nursing Implications
Assessment & Drug Effects
- Make appropriate inquiries about breakthrough bleeding, which may indicate that patient has missed successive drug doses.
Patient & Family Education
- Read the information pamphlet provided with nafarelin.
- Inform physician if breakthrough bleeding occurs or menstruation persists.
- Use or add barrier contraceptive during treatment.
Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; 
Canadian drug name; 
Prototype drug