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GOSERELIN ACETATE

Medical Diagnosis and Drugs, Medications
GOSERELIN ACETATE
(gos-er'e-lin)
Zoladex
Classifications: hormone; gonadotropin-releasing hormone (gnrh) analog;
Therapeutic: gnrh analog
Prototype: Leuprolide
Pregnancy Category: X

Availability

3.6 mg, 10.8 mg SC implant

Action

A synthetic form of luteinizing hormone-releasing hormone (LHRH or GnRH) that inhibits pituitary gonadotropin secretion.

Therapeutic Effect

With chronic administration, serum testosterone levels fall into the range normally seen with surgically castrated men.

Uses

Prostate cancer, breast cancer. Endometrial thinning agent prior to endometrial ablation for dysfunctional uterine bleeding.

Unlabeled Uses

Endometriosis, uterine leiomyomas.

Contraindications

Known hypersensitivity to an LHRH; vaginal bleeding; endometriosis or endometrial thinning; hypercalcemia; pregnancy (category X); lactation.

Cautious Use

Urinary tract obstruction and children; family history of osteoporosis; concurrent use with anticonvulsants or corticosteroids; osteoporosis; patients at risk for spinal cord compression or urinary tract obstruction. Safety and efficacy in children are not established.

Route & Dosage

Prostate Cancer, Breast Cancer, Endometriosis, Uterine Leiomyomas
Adult: SC 3.6 mg once q28d, 10.8 mg depot q12wk

Endometrial Thinning Prior to Endometrial Ablation
Adult: SC 3.6 mg once q28d

Administration

Subcutaneous
  • Follow manufacturer's directions exactly for implanting the drug SC in the upper abdominal wall.
  • Store at room temperature not to exceed 25° C (77° F).

Adverse Effects (≥1%)

CNS: Headache, tumor flare. Endocrine: Gynecomastia, breast swelling and tenderness, postmenopausal symptoms (hot flashes, vaginal dryness). GI: Nausea. Urogenital: Vaginal spotting, breakthrough bleeding, decreased libido, impotence. Musculoskeletal: Bone pain, bone loss.

Diagnostic Test Interference

Increased levels of alkaline phosphatase and estradiol in the first 1–8 d; initial increase then decrease in FSH, LH, and testosterone.

Interactions

Drug: No clinically significant interactions established.

Pharmacokinetics

Absorption: Rapidly absorbed following SC administration. Duration: 29 d. Elimination: Excreted by kidneys. Half-Life: 4.9 h.

Nursing Implications

Assessment & Drug Effects

  • Monitor carefully during the first month of therapy for S&S of spinal cord compression or ureteral obstruction in patients with prostate cancer. Report immediately to physician.
  • Anticipate a transient worsening of symptoms (e.g., bone pain) during the first weeks of therapy in patients with prostate cancer.

Patient & Family Education

  • Note: Sexual dysfunction in men and hot flashes may accompany drug use.
  • Notify physician immediately of symptoms of spinal cord compression or urinary obstruction.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug

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