goserelin acetate

go·se·rel·in acetate (gs-rln)

n.

A synthetic peptide analog of gonadotropin-releasing hormone used primarily to treat cancer of the breast and prostate, endometriosis, and infertility.

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goserelin acetate Warning - Hazardous drug!

Zoladex, Zoladex LA (CA), Zoladex 3-Month

Pharmacologic class: Gonadotropin-releasing hormone analog

Therapeutic class: Antineoplastic, hormone

Pregnancy risk category D (breast cancer), X (endometriosis)

Action

Synthetic form of luteinizing hormone-releasing hormone (LHRH); inhibits gonadotropin production by acting directly on pituitary gland. Enhances release of luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone, lowering testosterone and estradiol levels.

Availability

Implant: 3.6 mg, 10.8 mg (in preloaded syringes)

⊘Indications and dosages

➣ Palliative treatment of advanced prostate cancer

Adults: 3.6 mg subcutaneously q 4 weeks or 10.8 mg subcutaneously q 12 weeks into upper abdominal wall

➣ Adjunct to radiation therapy and flutamide in stage B2-C prostate cancer

Adults: 3.6 mg subcutaneously q 4 weeks starting on day 1 of radiation or during last week of radiation. Alternatively, 3.6 mg subcutaneously 8 weeks before radiation, then 10.8 mg on day 28 or 3.6 mg at 4-week intervals starting 8 weeks before radiation, for a total of four doses (two depots before and two during radiation therapy).

➣ Palliative treatment of advanced breast cancer in pre- and perimenopausal women

Adults: 3.6 mg subcutaneously q 4 weeks. If serum estradiol doesn't fall to postmenopausal levels, may increase to 7.2 mg q 4 weeks.

➣ Endometriosis

Adults ages 18 and older: 3.6 mg subcutaneously q 4 weeks, continued for 6 months

➣ Endometrial thinning before ablation for dysfunctional uterine bleeding

Adults: 3.6 mg subcutaneously 4 weeks before surgery. Alternatively, initial 3.6-mg dose may be followed 4 weeks later by a second 3.6-mg dose, with surgery 2 to 4 weeks after second dose.

Contraindications

• Hypersensitivity to drug or its components or to LHRH or LHRH-agonist analogs
• Undiagnosed vaginal bleeding
• Pregnancy or breastfeeding

Precautions

Use cautiously in:
• risk factors for osteoporosis
• chronic alcohol or tobacco use
• patients receiving drugs that affect bone density
• children younger than age 18 (safety not established).

Administration

• Administer pretreatment pregnancy test to female of childbearing age.
• Know that drug should be given only by a clinician experienced in its use.
• Implant is placed subcutaneously into upper abdominal wall using aseptic technique. Give local anesthetic and stretch skin with one hand. Insert needle into subcutaneous fat, then change needle angle until it parallels abdominal wall. Push needle in until hub touches patient's skin, and withdraw about 1 ml before depressing plunger all the way.
• Don't aspirate after inserting needle. Blood will be visible in syringe if needle enters blood vessel.
☞ Don't give by I.V. route.
• Be aware that 10.8-mg implant should not be used in women.
• Be aware that if implant must be removed, it can be located by ultrasound.

Route	Onset	Peak	Duration
Subcut.	Unknown	2-4 wk	End of therapy

Adverse reactions

CNS: headache, anxiety, depression, dizziness, fatigue, insomnia, lethargy, pain, emotional lability, weakness, cerebrovascular accident

CV: vasodilation, chest pain, hypertension, palpitations, peripheral edema, myocardial infarction, arrhythmias

EENT: blurred vision

GI: nausea, vomiting, diarrhea, constipation, ulcer, anorexia

GU: urinary obstruction, lower urinary tract symptoms, breast swelling or tenderness, vaginitis, amenorrhea, infertility, decreased libido, erectile dysfunction, other sexual dysfunction, decreased testicular size, renal insufficiency

Hematologic: anemia

Musculoskeletal: increased bone pain, joint pain, decreased bone density

Metabolic: gout, hyperglycemia, hypercalcemia

Respiratory: dyspnea, chronic obstructive pulmonary disease, upper respiratory tract infection

Skin: rash, acne, diaphoresis, seborrhea

Other: hirsutism, chills, fever, hot flashes, infection, weight gain

Interactions

Drug-diagnostic tests . Calcium, glucose, high- and low-density lipoproteins, triglycerides: increased levels

FSH, LH: initially increased, then decreased, levels

Patient monitoring

• Assess menstrual symptoms and watch for breakthrough bleeding.
• Monitor neurologic status. Watch closely for signs and symptoms of cerebrovascular accident.
• Monitor cardiovascular and respiratory status.

Patient teaching

• Advise female patient to avoid pregnancy and to use a nonhormonal contraceptive method.
• Instruct patient to call prescriber if menstrual bleeding persists or breakthrough bleeding occurs.
• Inform patient that menstruation may be delayed after therapy ends.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the tests mentioned above.

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goserelin acetate

Zoladex^® Oncology A LHRH/GRH analogue used to suppress pitutitary seretion of gonadotropins Indications Hormone-responsive prostate and breast CAs, uterine fibroids, endometriosis Adverse effects Hypersensitivity, rash, hypotension, HTN. See Androgen ablation therapy.