Triptorelin

Triptorelin, sold under the brand name Decapeptyl among others, is a medication that acts as an agonist analog of gonadotropin-releasing hormone, repressing expression of luteinizing hormone (LH) and follicle-stimulating hormone (FSH).

It is a decapeptide (pGlu-His-Trp-Ser-Tyr-D-Trp-Leu-Arg-Pro-Gly-NH₂) and a gonadotropin-releasing hormone agonist (GnRH agonist) used as the acetate or pamoate salts.

Primary indications include endometriosis, for the reduction of uterine fibroids, to treat prostate cancer, and to treat male hypersexuality with severe sexual deviation. The drug has also been used off label to delay puberty in patients with gender dysphoria.

It was patented in 1975 and approved for medical use in 1986. It is on the World Health Organization's List of Essential Medicines.

Triptorelin is used to treat prostate cancer as part of androgen deprivation therapy.

Another common use in the United Kingdom is for hormone replacement therapy to suppress testosterone or estrogen levels in transgender people (in conjunction with estradiol valerate for trans women or testosterone for trans men). Spironolactone and cyproterone acetate are other drugs used by trans people to suppress sex hormones, but these drugs have a completely different mechanism of action. It can also be used as a puberty blocker in the case of precocious puberty.

Triptorelin has been used as a chemical castration agent for reducing sexual urges in sex offenders.

Triptorelin is a gonadorelin analogue, also known as luteinizing hormone releasing analogue (GnRH analogue, LHRH analogue). The drug binds to receptors in the pituitary gland and stimulates secretion of gonadotropins (namely luteinizing hormone LH and follicle-stimulating hormone FSH). This causes an initial phase of LH and FSH stimulation, prior to down-regulation of the gonadotrophin-releasing hormone receptors, thereby reducing the release of gonadotropins in the long term, which in turn leads to the inhibition of androgen and estrogen production.

General side effects can include:

• Anaphylaxis
• Arthralgia
• Asthenia
• Asthma
• Breast tenderness (males and females)
• Changes in blood pressure
• Changes in breast size
• Depression
• Ovarian cysts
• Mood changes
• Skin rashes
• Hot flashes
• Weight changes

Triptorelin is marketed under the brand names Decapeptyl (Ipsen) for treating prostate cancer, endometriosis, uterine myomas, and precocious puberty, and Diphereline and Gonapeptyl (Ferring Pharmaceuticals). In the United States, it is sold by Watson Pharmaceuticals as Trelstar and by Arbor Pharmaceuticals as Triptodur (an extended-release 6-month depot injection). In Iran, triptorelin is marketed under the brand name Variopeptyl. In the UK and Germany, it is sold as Salvacyl for the treatment of sexual deviations.

Triptorelin was developed in Andrew V. Schally's lab at Tulane University. Debiopharm licensed the drug from Tulane in 1982.

Triptorelin and other antiandrogens may be effective in the treatment of obsessive–compulsive disorder.

Minimal daily dose of triptorelin acetate needed to suppress a premature LH surge during IVF treatment has been determined to be 15 microgram daily, and that 50 microg is equivalent to 100 microg in terms of IVF results.

The interval between initiation of study medication and start of FSH stimulation was defined as the desensitization phase.

For bothparameters, adjacent comparisons showed a statistically significant difference between the effect of placebo and 15 µgtriptorelin, but not between 15 and 50 µg, or between 50 and100 µg (Table II).

moreover, it appeared that a daily dose of 50 µg triptorelincreates a state of pituitary desensitization comparable with the ‘standard’ dose of 100 µg, and this endocrine finding was confirmed in the current study.

The systemic bioavailability of the active component triptorelin from the intramuscular depot is 38.3% in the first 13 days (2.9% per day). Further release is linear at 0.92% of the dose per day on average (34μg). Bioavailability after S.C. application is 69% of I.M. availability.

Plasma triptorelin values decreased to approx. 100 pg/ml before the next application after I.M. or S.C. application (median values).

• "Triptorelin". Drug Information Portal. U.S. National Library of Medicine.