Pharmacology · GnRH analogues (agonists and antagonists)
Triptorelin !
A long-acting GnRH agonist injection for advanced prostate cancer and early puberty in children. Hormones rise for a few weeks, then fall.
Updated 2026-11-01
Mechanism of action
Triptorelin is a long-acting GnRH agonist. A depot injection stimulates the pituitary GnRH receptors continuously: LH, FSH and sex steroids rise in the first weeks, then the receptors desensitise and testosterone or oestrogen fall. In children with central precocious puberty this pauses pubertal development.
- Continuously stimulates the pituitary GnRH receptor
- Brief rise of LH, FSH and sex hormones
- The receptors desensitise
- Sex hormones fall; puberty or tumour growth pauses
Pharmacokinetics
- Absorption
- Extended-release suspension injected into a muscle; released over weeks to months
- Onset and duration
- Hormones rise during the first weeks before falling
Indications
- Advanced prostate cancer Prostate cancer →
- Central precocious puberty
Adverse effects
Common
- Hot flushes and sweating
- Headache
- Decreased sexual desire or ability
- Constipation and heartburn
- Mood changes such as irritability or crying
- Vaginal bleeding in girls in the first weeks
Contraindications
- Hypersensitivity to triptorelin
- Pregnancy
Key interactions
- Drugs that prolong the QT interval
- Androgen deprivation can prolong the QT interval; effects may add up.
What is monitored
- Testosterone and PSA in prostate cancer
- Signs of puberty in children
- Blood glucose and lipids
- Cardiovascular symptoms
Administration and safety
- Long-acting suspension injected into a muscle by a health professional; schedules differ by product.
- Prepared exactly as the product instructions describe.
Nursing care
- Ask about long QT syndrome, diabetes and spinal metastases before starting.
- In the first weeks, watch for bone pain, urinary difficulty or leg weakness in men with prostate cancer.
- Tell families that some pubertal signs or spotting may appear in the first weeks in children.
- Teach to report mood changes, seizures, chest pain or one-sided weakness.
Pregnancy and breastfeeding
Not used in pregnancy; pregnancy is reported at once if it occurs during treatment.
Test yourself
Think of the answer, then tap the question to see it.
Which two main uses does triptorelin have?
Advanced prostate cancer and central precocious puberty in children.
A girl starting triptorelin for precocious puberty has spotting in the first weeks. Why?
The agonist first raises sex hormones before suppressing them; a brief worsening of pubertal signs or spotting can occur early.
Which neurological adverse effect is listed for triptorelin?
Seizures; the patient is asked about a history of seizures and risk factors.
Related drugs
Related conditions
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Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: Triptorelin Injection: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2026); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026); Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed., ch. 46 (McGraw Hill, 2023).
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Representative model, for educational purposes only.