Triptorelin

Triptorelin is a synthetic ten-amino-acid GnRH analog, also called D-Trp6-LHRH. Salt names include pamoate, acetate and embonate. Brands include Trelstar and Triptodur, with Decapeptyl used outside the US. Debiopharm developed the molecule; microsphere depots release it over weeks or months. US approval began in 2000.

GnRH-receptor activation initially raises LH, FSH and testosterone. Continued depot exposure desensitizes and downregulates the pituitary, reducing gonadotropins and testosterone to castrate levels. This deprives hormone-sensitive prostate tumors of a growth signal and interrupts the early reproductive-hormone signal in central precocious puberty.

In a randomized leuprolide comparison, initial testosterone suppression was slightly slower with triptorelin, but maintenance of castrate levels was equivalent through nine months. Depots last one, three or six months. Pediatric six-month Triptodur is administered twice yearly.

Available depot intervals include one, three and six months; the relevant product and indication must be matched.

Clinicians use triptorelin for palliative treatment of advanced prostate cancer in men and for central precocious puberty in children. A healthcare professional administers the intramuscular injection at the interval specified for that depot.

Men may experience hot flashes, bone pain, headache, erectile dysfunction, testicular shrinkage and leg pain or swelling. In children, common effects include injection reactions, early vaginal bleeding, hot flashes, headache, cough and respiratory infections.

Serious considerations include initial disease flare, longer-term hyperglycemia/diabetes and cardiovascular risk with androgen deprivation, serious allergy, severe skin reactions and convulsions. Pediatric warnings also include mood changes and increased intracranial pressure.