histrelin


histrelin

 [his-trel´in] a synthetic preparation of hormone" >gonadotropin-releasing hormone, used as the acetate ester in treatment of puberty" >precocious puberty.

histrelin

(hiss-tre-lin) histrelin,

Supprelin LA

(trade name),

Vantas

(trade name)

Classification

Therapeutic: hormones
Pharmacologic: gonadotropin releasing hormones
Pregnancy Category: X

Indications

Palliative treatment of advanced prostate cancer (Vantas).Central precocious puberty (Supprelin LA).

Action

Continuous administration decreases production of gonadotropins.

Therapeutic effects

Suppression of testosterone production.Prevention of disease progression.

Pharmacokinetics

Absorption: Highly absorbed (92%) from implant. Peak absorption occurs at 12 hours, and continues over 1–year period.Distribution: Unknown.Protein Binding: 29%.Metabolism and Excretion: Unknown.Half-life: 3.92 hours.

Time/action profile (↓ in LH, FSH, and sex-steroid levels)

ROUTEONSETPEAKDURATION
Subcutunknown12 hr52 wk

Contraindications/Precautions

Contraindicated in: Hypersensitivity to any component of the product, GnRH, or GnRH agonist analogs; Women.Use Cautiously in: Patients with metastatic vertebral lesions or urinary tract obstruction (initial transient ↑ in testosterone may worsen symptoms); Pediatric: Children <2 yr (safety not established) (Supprelin LA).

Adverse Reactions/Side Effects

Central nervous system

  • stroke (life-threatening)
  • headache (most frequent)
  • anxiety
  • depression
  • dizziness
  • insomnia
  • irritability
  • lethargy
  • malaise
  • seizures

Ear, Eye, Nose, Throat

  • visual disturbances

Respiratory

  • dyspnea

Cardiovascular

  • Myocardial infarction (life-threatening)
  • vasodilation (most frequent)
  • edema
  • palpitations
  • tachycardia

Gastrointestinal

  • hepatotoxicity (life-threatening)
  • abdominal discomfort
  • constipation
  • nausea
  • vomiting

Genitourinary

  • dysuria
  • hematuria
  • polyuria
  • urinary retention

Dermatologic

  • acne
  • ↑ sweating
  • pruritis
  • rash

Endocrinologic

  • breast discharge
  • breast pain
  • genital pruritis
  • ↑ breast size

Hematologic

  • anemia

Local

  • itching, erythema, and swelling at implantation site (most frequent)

Metabolic

  • hypercalcemia
  • hyperglycemia
  • hyperlipidemia

Musculoskeletal

  • arthralgia
  • bone pain
  • joint stiffness
  • muscle cramps
  • muscle stiffness
  • myalgia

Neurologic

  • tremor

Miscellaneous

  • allergic reactions including angioedema (life-threatening)
  • hot flashes (most frequent)
  • ↑ appetite
  • ↑ pain

Interactions

Drug-Drug interaction

Unknown.

Route/Dosage

Prostate Cancer

Subcutaneous (Adults) 50 mg implant inserted every 12 mo.

Central Precocious Puberty

Subcutaneous (Children ≥2 yr) 50 mg implant inserted every 12 mo.

Availability

Injection: 50 mg/implant

Nursing implications

Nursing assessment

  • Obtain a complete physical and endocrinologic examination, including height, weight, before starting, after 3 mo and every 6–12 mo during therapy.
  • Assess for signs of disease progression periodically throughout therapy.
  • Monitor patient for signs of hypersensitivity (angioedema, urticaria, hypotension, tachycardia, loss of consciousness, bronchospasm, dyspnea, flushing, pruritus). Discontinue therapy if any of these symptoms occur.
  • Lab Test Considerations: Monitor LD, FSH, estradiol, or testosterone at 1 mo after implantation and every 6 mo thereafter.
    • May cause ↑ AST and LDH; usually reversible with removal of implant.

Potential Nursing Diagnoses

Sexual dysfunction (Indications)
Deficient knowledge, related to medication regimen (Patient/Family Teaching)

Implementation

  • Subcutaneous: Histrelin is given as a single yearly subcutaneous implant. The implant must be removed after 12 mo of therapy. Subsequent implantation may be used to continue therapy.

Patient/Family Teaching

  • Instruct patient to not to get arm wet for 24 hrs and to avoid strenuous lifting for 7 days after insertion.
  • Inform patient and family that if implants are not given yearly, disease may progress.
  • Advise patient and family that during initial agonistic phase (1–3 wk) the patient may have transient symptom worsening or onset of new symptoms, including bone pain, neuropathy, hematuria, or urinary tract obstruction.
  • Inform patient and family that redness or swelling may occur at the implantation site, especially after initial implantation or implant removal. Notify health care professional if this reaction is severe or does not go away.
  • Instruct patient and family to contact health care professional at the first sign of skin rash, urticaria, rapid heartbeat, difficulty swallowing or breathing, or any swelling that may suggest angioedema.

Evaluation/Desired Outcomes

  • Palliation of signs and symptoms associated with prostate cancer.
  • Delay of early onset of puberty.