Synarel (nafarelin acetate)

Dosage of nafarelin acetate is expressed in terms of nafarelin. After initial priming, the commercially available nasal pump delivers 200 mcg of nafarelin per spray and delivers approximately 60 sprays.

Missed doses may cause breakthrough bleeding or ovulation, or restart pubertal development. Full efficacy is dependent on dosage compliance for the full duration of treatment.

No dosing information is available for this tab.

No dosing information is available for this tab.

No pharmacokinetic drug interaction studies have been performed. The manufacturer states that because nafarelin is a peptide that is mainly degraded by peptidases and not by cytochrome P-450 (CYP) microsomal enzymes and because of the drug's limited protein binding, drug interactions are not expected to occur.

Administration of the topical nasal decongestant should be delayed until at least 2 hours after administration of nafarelin.

There are no contraindication interactions for this drug.

There are no severe interactions for this drug.

There are no moderate interactions for this drug.

Known hypersensitivity to nafarelin or any ingredient in the formulation, other gonadotropin-releasing hormone (GnRH) agonists, or GnRH. Known or suspected pregnancy or lactation. Abnormal vaginal bleeding of unknown etiology.

• Lactation
• Pregnancy

There are no severe contraindications for this drug.

• Alcohol use disorder
• Diabetes mellitus
• Hypercholesterolemia
• Hypertension
• Obesity
• Osteopenia
• Osteoporosis
• Tobacco smoker

Symptoms suggestive of drug sensitivity (e.g., shortness of breath, chest pain, urticaria, rash, pruritus) have been reported in 0.2% of women and 2.6% of children in clinical studies.

Adverse effects occurring in 10% or more of women include hot flushes (flashes), decreased libido, vaginal dryness, headache, emotional lability, acne, myalgia, reduction in breast size, and nasal irritation. Decreases in bone mineral density have occurred in women receiving nafarelin; concurrent use of hormone replacement therapy or bisphosphonates (e.g., alendronate) minimizes bone mineral loss associated with GnRH agonist therapy without compromising efficacy of these drugs in the management of endometriosis. (See Cautions: Endocrine Effects and see Precautions and Contraindications, in Leuprolide Acetate 68:18.08.)

Adverse effects reported in 3% or more of children include acne, transient breast enlargement, emotional lability, transient increases in pubic hair, body odor, seborrhea, hot flushes (flashes), rhinitis, vaginal bleeding, and white or brown vaginal discharge.

More Frequent

• Menorrhagia

Less Frequent

• Chest pain
• Osteopenia

Rare or Very Rare

• Abnormal hepatic function tests
• Acute myocardial infarction
• Allergic dermatitis
• Cerebrovascular accident
• Deep venous thrombosis
• Diabetes mellitus
• Dyspnea
• Hepatocellular damage
• Idiopathic intracranial hypertension
• Ovarian cyst
• Ovarian enlargement
• Ovarian hyperstimulation syndrome
• Pituitary apoplexy
• Pulmonary thromboembolism
• Seizure disorder
• Suicidal ideation
• Transient cerebral ischemia
• Urticaria

More Frequent

• Abnormal vaginal bleeding
• Acne vulgaris
• Amenorrhea
• Flushing
• Hypoestrogenism
• Weight gain

Less Frequent

• Drug-induced hot flash
• Gynecomastia
• Headache disorder
• Hyperlipidemia
• Increased pubic hair
• Maculopapular rash
• Mood changes
• Skin rash
• Vaginal discharge

Rare or Very Rare

• Aggressive behavior
• Agitation
• Arthralgia
• Body odor
• Breast engorgement
• Chloasma
• Depression
• Galactorrhea not associated with childbirth
• General weakness
• Hostility
• Irritability
• Mastalgia
• Ocular pain
• Pruritus of skin
• Rhinitis
• Seborrhea
• Weight loss

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Safety and efficacy of nafarelin in children (younger than 18 years of age) for uses (e.g., endometriosis) other than the treatment of central precocious puberty have not been established.

Category X. (See Warnings: Fetal/Neonatal Morbidity and Mortality, in Cautions.)

Not known whether nafarelin is distributed into milk. Nafarelin should not be used in nursing women.

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