triptorelin pamoate
Pharmacologic class: Synthetic agonist analog of luteinizing hormone-releasing hormone (LHRH)
Therapeutic class: Antineoplastic
Pregnancy risk category X
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.
☞ 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.
☞ 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.