Decapeptyl SR

Action

Initially causes surge in luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone levels. After several weeks of therapy, LH and FSH secretion decrease, causing sustained testosterone reduction equivalent to pharmacologic castration.

Availability

Microgranules for injection (lyophilized): 3.75 mg (depot), 11.25 mg (long-acting), 22.5 mg (long-acting)

Indications and dosages

➣ Palliative treatment of advanced prostate cancer

Adults: 3.75 mg (depot) I.M. monthly as a single injection or 11.25 mg (long-acting) I.M. q 12 weeks as a single injection or 22.5 mg (long-acting) I.M. q 24 weeks

Off-label uses

• Infertility

• Endometriosis

• Uterine fibroids

• Precocious puberty

Contraindications

• Hypersensitivity to drug, LHRH, or other LHRH agonists

• Pregnancy

• Women of childbearing potential

Precautions

Use cautiously in:

• renal insufficiency

• prostate cancer with impending spinal cord compression or severe urinary tract disorder

• breastfeeding patients (use not recommended).

Administration

• Reconstitute with 2 ml of sterile water for injection, using accompanying syringe (don't use other diluents). Add syringe contents to vial containing particles; shake well. Withdraw vial contents and inject I.M. immediately.

• Inject deep I.M. into either buttock. Rotate injection sites.

See Keep epinephrine and emergency equipment at hand in case of anaphylactic reaction.

Adverse reactions

CNS: insomnia, dizziness, headache, emotional lability, fatigue, stroke

CV: hypertension, increased risk of myocardial infarction and sudden cardiac death

GI: vomiting, diarrhea

GU: urinary retention, urinary tract infection, gynecomastia, erectile dysfunction, testicular atrophy

Hematologic: anemia

Metabolic: hyperglycemia

Musculoskeletal: skeletal or leg pain

Skin: pruritus

Other: leg edema, temporary worsening of disease, edema, hot flashes, pain at injection site, hypersensitivity reactions including anaphylaxis

Interactions

Drug-diagnostic tests. Hemoglobin: decreased value

Pituitary-gonadal function tests: misleading results (with continuous or long-term use)

Serum glucose: increased

Patient monitoring

• Monitor serum testosterone and prostate-specific antigen levels periodically to assess drug efficacy.

See Monitor patient for signs and symptoms suggestive of cardiovascular disease and manage as appropriate.

Patient teaching

• Explain drug therapy to patient. Stress need for follow-up laboratory tests.

• Tell patient prostate cancer symptoms may worsen during first few weeks of therapy.

• Instruct patient to monitor weight and report sudden weight gain or leg swelling.

• Advise female patient to tell prescriber before starting therapy if she is or plans to become pregnant. Caution her not to breastfeed during therapy.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs and tests mentioned above.