Triptorelin is an analogue of gonadorelin () with similar properties. It is used for the suppression of gonadal sex hormone production in the treatment of malignant neoplasms of the prostate, deviant sexual behaviour in men, precocious puberty, and in the management of endometriosis, female infertility, and uterine fibroids. Triptorelin may be given as the base, acetate, diacetate, or embonate, although for some preparations stated to contain the acetate or diacetate it is not always clear which has actually been used. Doses are usually given in terms of the base, and the following are each equivalent to about 1 mg of triptorelin:
- triptorelin acetate, 1.05 mg
- triptorelin diacetate, 1.09 mg
- triptorelin embonate, 1.30 mg
Triptorelin is given as a daily subcutaneous injection, or as an intramuscular or subcutaneous depot preparation lasting a month or longer.
In the palliative treatment of advanced prostate cancer, a dose equivalent to triptorelin 3 or 3.75 mg is given intramuscularly as a depot preparation every 4 weeks the first dose may be preceded by 100 micrograms daily for 7 days by subcutaneous injection. In some countries, depot preparations containing 3.75 mg may be given subcutaneously instead. A longer-acting depot preparation that contains the equivalent of triptorelin 11.25 mg is given once every 12 to 13 weeks. In some countries, depot doses of 3 mg once every 4 weeks or 11.25 mg once every 12 to 13 weeks may also be used for medical therapy in locally advanced disease. An anti-androgen such as cyproterone acetate may be given for several days before beginning therapy with triptorelin and continued for about 3 weeks to avoid the risk of a disease flare.
An 11.25-mg intramuscular depot preparation, given every 12 weeks, may be used in the management of deviant sexual behaviour in men. The addition of an anti-androgen should be considered when starting therapy, to counteract the initial rise in serum-testosterone concentrations.
Similar doses of the 3- or 3.75-mg depot preparations may be given for up to 6 months in the management of endometriosis or uterine fibroids, with treatment begun during the first 5 days of the menstrual cycle. The 11.25-mg depot may be used as an alternative for endometriosis. In the management of female infertility doses of 100 micrograms subcutaneously daily, with gonadotrophins, have been recommended from the second day of the menstrual cycle for about 10 to 12 days.
In children with precocious puberty a dose equivalent to triptorelin 50 micrograms/kg from the 3-mg depot preparation may be given intramuscularly every 4 weeks. Alternatively, using the 3.75-mg preparation, doses of 1.875 mg for children weighing less than 20 kg, 2.5 mg for children of 20 to 30 kg, or 3.75 mg for children of more than 30 kg may be given intramuscularly or subcutaneously the first 3 doses should be given at 14-day intervals, with further doses given every 4 weeks. The longer acting 11.25-mg depot preparation, given intramuscularly once every 3 months, is another alternative.
Delayed and precocious puberty. Gonadorelin analogues such as triptorelin are used in the management of central precocious puberty (). They may also be effective in delayed puberty () although they are most likely to be helpful where this is due to hypogonadism. Triptorelin has been used to differentiate gonadotrophin deficiency from constitutional delayed puberty, although one study found it to be less accurate than a test using human chorionic gonadotrophin.
Disturbed behaviour. Combined therapy with triptorelin, which suppressed testosterone secretion by inhibiting the pituitary-gonadal axis, and supportive psychotherapy, has been tried in the treatment of men with paraphilias (): a reduction in abnormal sexual thoughts and behaviours has been reported, although the study was uncontrolled.
Endometriosis. Gonadorelin analogues are effective in the management of endometriosis (), but the need for long-term therapy to prevent recurrence limits their value because of the risk of osteoporosis ‘add-back’ therapy (hormone replacement) can be used to prevent this.
Fibroids. Gonadorelin analogues have been used as an alternative to surgery in the treatment of uterine fibroids (), despite some concern that this may complicate the diagnosis of malignancy. References to the use of triptorelin.
Growth retardation. As discussed gonadorelin analogues have been given with growth hormone to short girls without growth hormone deficiency, in an attempt to delay puberty and bone maturation and thus maximise the final height achieved. Use in growth hormone-deficient children has also been investigated. However, there is some doubt about the extent of benefit, and in any case the concept of such treatment in children who are not clinically deficient in growth hormone is controversial, and some authorities do not consider it appropriate.
Infertility. Gonadorelin analogues are used in the management of infertility related to hypogonadotrophic hypogonadism in both men and women. For a discussion of infertility and its management, including the role of gonadorelin analogues.
Malignant neoplasms. Triptorelin, like other gonadorelin analogues, may be used in the production of androgen blockade in patients with prostate cancer ().
Porphyria. Triptorelin has been used successfully to suppress premenstrual exacerbations of acute intermittent porphyria (), in doses of 3.75 mg by intramuscular depot injection given monthly. To reduce the risk of osteoporosis, ‘ add-back’ therapy with topical oestrogen and oral calcium was used in one case, and tibolone in another.
Argentina: Decapeptyl Gonapeptyl
Austria: Decapeptyl Pamorelin
Brazil: Neo Decapeptyl
Czech Republic: Decapeptyl Diphereline
Denmark: Decapeptyl Pamorelin
France: Decapeptyl Gonapeptyl
Germany: Decapeptyl Pamorelin
Greece: Arvekap Go-napeptyl
Hong Kong: Decapeptyl Diphereline
Hungary: Decapeptyl Diphereline
Ireland: Decapeptyl Gonapeptyl
Israel: Decapeptyl Diphereline
Italy: Decapeptyl Gonapeptyl
Mexico: Trelstar †
The Netherlands: Decapeptyl Gonapeptyl Pamorelin
Poland: Decapeptyl Diphereline
Russia: Decapeptyl () Diphereline ()
South Africa: Decapeptyl
Spain: Decapeptyl Gonapeptyl
Sweden: Decapeptyl Moapar
Thailand: Decapeptyl Diphereline
UK: Decapeptyl Gonapeptyl
The symbol † denotes a preparation no longer actively marketed
Selections from the book: “Martindale: The Complete Drug Reference. Thirty-sixth edition”. Pharmaceutical Press. 2009