Triptorelin Pamoate

Pronunciation: TRIP-toe-REL-in PAM-oh-ate
Class: Gonadotropin-releasing hormone

Trade Names

Trelstar
- Injection, lyophilized microgranules for suspension 3.75 mg
- Injection, lyophilized microgranules for suspension 11.25 mg
- Injection, lyophilized microgranules for suspension 22.5 mg

Trelstar (Canada)

Pharmacology

Synthetic analog of gonadotropin-releasing hormone (GnRH) that acts as potent inhibitor of gonadotropin secretion.

Slideshow: The Ferocity of Chemotherapy - Does The End Justify The Means?

Pharmacokinetics

Absorption

C max is approximately 28.43 ng/mL, 38.5 ng/mL, and 44.1 ng/mL for triptorelin 3.75 mg, 11.25 mg, and 22.5 mg, respectively. T max is 1 to 3 h.

Distribution

Vd is 30 to 33 L (from an IV dose of 0.5 mg). There is no evidence of protein binding.

Metabolism

No metabolites are found. Pharmacokinetic data suggest that C-terminal fragments produced by tissue degradation are either completely degraded in the tissues or are rapidly degraded further in plasma, or cleared by the kidneys.

Elimination

Triptorelin is eliminated by both the liver and kidneys. 41.7% of a dose is excreted in urine.

Peak

Time to peak effect occurs on day 4, days 2 to 3, or on day 3 for triptorelin 3.75 mg, 11.25 mg, or 22.5 mg, respectively.

Duration

Duration of action is 4 wk for triptorelin 3.75 mg, and 3 to 4 wk for triptorelin 11.25 and 22.5 mg.

Special Populations

Renal Function Impairment

There is a decrease in total Cl proportional to decrease in CrCl and increased Vd and half-life. Patients with renal impairment had 2- to 4-fold higher exposure (AUC) values than younger healthy men.

Hepatic Function Impairment

The decrease in triptorelin Cl is more pronounced. Triptorelin half-life increase is similar to renal impairment. Patients with hepatic impairment had 2- to 4-fold higher exposure (AUC) values than younger healthy men.

Elderly

Triptorelin clearance is partly correlated to total CrCl, which is well known to decrease with age.

Children

Not evaluated in patients younger than 18 y of age.

Race

The effects of race have not been systematically studied.

Indications and Usage

Palliative treatment of advanced prostate cancer.

Unlabeled Uses

Treatment of ovarian cancer, pancreatic carcinoma, endometriosis, hyperandrogenism, growth hormone deficiency, in vitro fertilization, uterine leiomyomata, central precocious puberty.

Contraindications

Hypersensitivity to triptorelin or any component of product, or other GnRH agonists or GnRH; pregnancy.

Dosage and Administration

Advanced Prostate Cancer
Adults

IM Dosing schedule depends on product strength selected. 3.75 mg once every 4 wk; 11.25 mg once every 12 wk; 22.5 mg once every 24 wk.

General Advice

  • For IM use only.
  • Because of different release characteristics, dosage strengths are not additive and must be selected based upon the desired dosing schedule.
  • Reconstitute with sterile water; do not use any other diluent.
  • Administer triptorelin with a 21-guage needle immediately after reconstitution.
  • Inject into either buttock; rotate injection sites.

Storage/Stability

Store at 68° to 77°F. Do not freeze.

Drug Interactions

Hyperprolactinemic drugs

Do not coadminister with triptorelin because hyperprolactinemia reduces the number of pituitary GnRH receptors.

Laboratory Test Interactions

Because chronic or continuous administration of triptorelin suppresses pituitary-gonadal axis, diagnostic tests of the pituitary-gonadal function performed during triptorelin treatment or after cessation of therapy may be misleading.

Adverse Reactions

CNS

Headache (8%); insomnia (5%); dizziness (3%); fatigue (2%); emotional lability, asthenia (1%).

Dermatologic

Rash (2%); pruritus (1%).

EENT

Conjunctivitis, eye pain (1%).

GI

Nausea (3%); anorexia, constipation, dyspepsia, vomiting (2%); abdominal pain, diarrhea (1%).

Genitourinary

UTI (12%); erectile dysfunction (10%); testicular atrophy (8%); impotence (7%); dysuria, urinary retention (5%); breast pain, decreased libido, gynecomastia (2%).

Lab Tests

Decreased hemoglobin and red blood cell count, increased glucose, BUN, AST, ALT, and alkaline phosphatase (10% or more).

Metabolic

Leg edema (6%); diabetes mellitus/hyperglycemia, peripheral edema (5%); dependent edema (2%).

Musculoskeletal

Skeletal pain (13%); back pain (11%); arthralgia, pain in extremity (8%); leg pain (5%); leg cramps (2%); myalgia (1%).

Respiratory

Bronchitis (5%); coughing (2%); dyspnea, pharyngitis (1%).

Miscellaneous

Hot flushes (73%); influenza (16%); hypertension (14%); injection-site pain (4%); pain (3%); chest pain (2%); abnormal hepatic function, anemia (1%); pituitary apoplexy (postmarketing).

Precautions

Monitor

Monitor response to triptorelin by measuring serum levels of testosterone. Closely observe patients with metastatic vertebral lesions and/or with upper or lower urinary tract obstruction during the first few weeks of therapy.


Pregnancy

Category X .

Lactation

Undetermined.

Children

Safety and efficacy not established.

Hypersensitivity

Anaphylactic reactions reported.

Worsening of signs and symptoms

Initial transient increase in testosterone may lead to worsening of signs and symptoms of prostate cancer (eg, bone pain, urethral or bladder outlet obstruction) during first few weeks of treatment. Cases of spinal cord compression have been reported with GnRH agonists.

Patient Information

  • Advise patient, family, or caregiver that medication will be prepared and administered by a health care provider in a health care setting.
  • Educate patient, family, or caregiver of importance of returning as scheduled for additional injections in order to achieve maximal benefits from the medication.
  • Advise patient, family, or caregiver that medication may temporarily worsen signs and symptoms of the disease (eg, bone pain, blood in urine, difficult or painful urination) but that these should improve in 3 to 4 wk.
  • Advise patient, family, or caregiver to immediately report any of the following to the health care provider: rash; itching or hives; swelling of the face, lips, eyes, or tongue; wheezing; shortness of breath; difficulty breathing; weakness or paralysis of legs; inability to urinate.

Copyright © 2009 Wolters Kluwer Health.

Hide
(web4)