Histrelin acetate
Histrelin Acetate (Synarel)
Histrelin Acetate
(hiss- TREL-in)
Pregnancy Category: X Supprelin Synarel (Rx)

Classification: Gonadotropin-releasing hormone

Action/Kinetics: Histrelin contains a synthetic nonapeptide agonist of the naturally occurring GnRH. Initially the drug stimulates release of GnRH; however, chronic use desensitizes responsiveness of the pituitary gonadotropin, causing a reduction in ovarian and testicular steroidogenesis. Decreases in LH, FSH, and sex steroid levels are observed within 3 months of initiation of therapy.

Uses: To control the biochemical and clinical symptoms of central precocious puberty (either idiopathic or neurogenic) occurring before 8 years of age in girls or 9.5 years of age in boys.

Contraindications: Hypersensitivity to the product or any of its components. Lactation.

Special Concerns: Acute, serious hypersensitivity reactions may occur that require emergency medical treatment. Safety and efficacy in children less than 2 years of age have not been determined.

Side Effects: Acute hypersensitivity reaction: Angioedema, urticaria, CV collapse hypotension, tachycardia, loss of consciousness, bronchospasm dyspnea, flushing, pruritus. CV: Vasodilation (common), edema, palpitations, tachycardia, epistaxis, hypertension, migraine headache, pallor. GI: GI or abdominal pain, N&V;, diarrhea, flatulence, decrease appetite, dyspepsia, GI cramps or distress, constipation, decreased appetite, thirst, gastritis. CNS: Headache (common), nervousness, dizziness, depression, changes in libido, mood changes, insomnia, anxiety, paresthesia, syncope, somnolence, cognitive changes, lethargy, impaired consciousness, tremor, hyperkinesia, convulsions (increased frequency), hot flashes or flushes, conduct disorder. Endocrine: Vaginal dryness, leukorrhea, metrorrhagia, breast pain, breast edema, decreased breast size, breast discharge, tenderness of female genitalia, anemia, goiter, hyperlipidemia, glycosuria. Musculoskeletal: Arthralgia, joint stiffness, muscle cramp or stiffness, myalgia, hypotonia, pain. Respiratory: Cough, URI, pharyngitis, respiratory congestion, asthma, breathing disorder, rhinorrhea, bronchitis, sinusitis, hyperventilation. Dermatologic: Commonly, redness, itching, and swelling at the injection site. Also, urticaria, sweating, keratoderma, pruritus, pain, dyschromia, alopecia, erythema. Ophthalmologic: Visual disturbances, abnormal pupillary function, polyopia, photophobia. Otic: Otalgia, hearing loss. GU: Vaginal bleeding (most often one episode within 1-3 weeks after starting therapy and lasting several days). Also, vaginitis, dysmenorrhea, and problems of the female genitalia including pruritus, irritation, odor, pain, infections, and hypertrophy. Dyspareunia, polyuria, dysuria, incontinence, urinary frequency, hematuria, nocturia. Miscellaneous: Pyrexia (common), weight gain, fatigue, viral infection, chills, various body pains, malaise, purpura.

How Supplied: Kit: 0.5 mg/mL, 1 mg/mL

Dosage
?SC Central precocious puberty.
10 mcg/kg given as a single, daily SC injection. Doses greater than 10 mcg/kg/day have not been evaluated.