Triptorelin — Drug Monograph

Brand names: Trelstar, Triptodur

Drug class: Hormonal Agent

Mechanism of Action

Triptorelin is a synthetic decapeptide agonist analog of gonadotropin-releasing hormone (GnRH/LHRH). After an initial stimulatory phase in which it transiently increases luteinizing hormone (LH), follicle-stimulating hormone (FSH), and consequently testosterone, continuous (rather than pulsatile) receptor stimulation downregulates and desensitizes pituitary GnRH receptors. This leads to sustained suppression of LH and FSH secretion and, within 2-4 weeks, reduction of serum testosterone to castrate levels. The resulting profound androgen deprivation suppresses growth of androgen-dependent…

FDA Indications

• Palliative treatment of advanced prostate cancer (Trelstar depot 3.75 mg [1-month], 11.25 mg [3-month], and 22.5 mg [6-month] IM formulations)
• Central precocious puberty in pediatric patients 2 years and older (Triptodur 22.5 mg 6-month formulation)

Common Side Effects

• Hot flushes / flushing
• Decreased libido and erectile dysfunction
• Injection-site pain or reaction
• Fatigue
• Headache
• Skeletal / musculoskeletal pain
• Hypertension
• Gynecomastia

Clinical Pearl

Like all GnRH agonists, triptorelin causes an initial testosterone surge that can produce a clinical tumor flare during the first 1-2 weeks — patients with high tumor burden, vertebral metastases, or urinary obstruction are at risk for spinal cord compression or worsening obstruction, so a short course of an antiandrogen started before or at initiation blunts this effect. Confirm castrate testosterone levels after starting therapy, and remember that ADT carries longer-term metabolic and…

Related Therapies & Mechanisms

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