Triptorelin

Definition

Triptorelin pamoate is a synthetic luteinizing hormone-releasing hormone (LHRH) agonist, that is, a substance that reduces the level of sexual hormones in the system.

Purpose

Since its approval by the FDA (Food and Drug Administration) in June of 2000, triptorelin pamoate has been recognized as a successful option in the treatment of long-term cancer of the prostate gland. The prostate gland is a solid, chestnut-shaped organ surrounding the male urethra. It produces secretions that become part of seminal fluid. In the case of cancer of the prostate gland, it is advantageous to reduce prostate gland cell activity. One way to do this is to reduce the amount of hormones circulating in the system that will stimulate prostate activity. LHRH-agonists, such as triptorelin, are indicated when either orchiectomy (surgical removal of one of both testes) or the administration of the female hormone estrogen is either inadvisable or considered unacceptable by the person suffering from the cancer.

Triptorelin pamoate has been successfully used to alleviate symptoms in cases of such advanced prostate cancer, and is now being used and researched as a treatment for:

• all prostate cancers

• ovarian cancer

• in vitro fertilization

• endometriosis, or chronic disease of the mucous membrane lining the uterus

• uterine leiomyoma, also called uterine fibroids, a non-cancerous growth on the smooth muscle of the uterine wall

• precocious puberty, a condition in which children of either sex may undergo pubescent changes at an abnormally early age

• fibrocystic breast disease, or the presence of one or more benign tumors in the breast

Description

The human body provides balance in the provision of all chemicals necessary to its function. The pituitary gland and hypothalamus in the brain interact to release substances called gonadotropins, which trigger and regulate the production of estrogen (female) and androgen (male) hormones. Synthetic LHRH medications (similar in chemical makeup to natural LHRH enzymes) reduce the quantity of natural gonadotropins released. This reduces cell activity occurring in organs affected by these hormones, such as the prostate gland, ovaries, testes, uterus, and breasts, therefore slowing the growth of cancerous cells.

Triptorelin is a potent synthetic LHRH medication, effectively reducing gonadotropins if administered to maintain a continuous, therapeutic level in the body. Initially, there is often a temporary surge in circulating amounts of both male and female hormones, but usually within two to four weeks of beginning therapy, there is a marked reduction of these sex hormones. In men, there is a reduction in testosterone in the blood stream comparable to the level usually seen in surgically castrated men. Consequently, cells that rely upon these hormones for stimulation become less active. In most cases, the effect of triptorelin pamoate on sexual hormones is reversible once treatment is completed.

Recommended dosage

For advanced prostate cancer, the most common application for triptorelin, the usual dose is 3.75 milligrams (mg) given once per month as a single intramuscular injection. This will normally maintain a therapeutic level. If necessary, this medication may also be given intravenously.

Precautions

In the treatment of prostate cancer, there have been reported flare-ups of the disease at the onset of therapy. Patients with a prostate tumor affecting the spinal cord or urinary flow should use caution, as an increase in tumor activity may initially worsen symptoms. Triptorelin pamoate is capable of causing harm to fetuses if administered to pregnant women. During long-term treatment of endometriosis or uterine fibroids, bone loss has been reported.

Side effects

The following side effects have either been reported or were observed:

• nausea and vomiting

• hot flashes

• vaginal dryness

• impotence

• loss of sex drive

• breakthrough bleeding

• sleep disturbance

• diarrhea

• fatigue

• hair loss (alopecia)

• mouth sores

• breast tenderness

• weight gain

• pain at injection site

• increases in cholesterol

• headache

Interactions

Because triptorelin pamoate has only had FDA approval since June of 2000, not all information in known regarding its interactions with other medicines. Currently, no drug interactions have been reported.