📋 Clinical Overview

Triptorelin is a synthetic decapeptide analogue of Gonadotropin-Releasing Hormone (GnRH). It acts as a potent GnRH agonist. Following initial stimulation, continuous administration leads to a profound and sustained suppression of pituitary gonadotropins (LH and FSH), resulting in a medical castration or suppression of ovarian/testicular steroidogenesis. The 0.5mg/ml strength is typically used for daily subcutaneous administration in specific protocols.

💊 Dosage & Administration

Adult: Prostate Cancer/Endometriosis/Fibroids: 0.5 mg (1 ml of 0.5 mg/ml solution) administered subcutaneously once daily. The injection site should be rotated. For long-term management, patients are often switched to a long-acting depot formulation (e.g., 3.75 mg monthly) after initial stabilization.
Pediatric: Central Precocious Puberty: 20-50 mcg/kg (0.02-0.05 mg/kg) administered subcutaneously once daily. Dose is titrated based on clinical (growth velocity, pubertal signs) and biochemical (LH, FSH, sex steroid) response. Not a first-line choice for CPP in India; depot formulations are preferred.
Renal Adjusment: Mild to moderate impairment: No specific adjustment needed. Severe impairment (CrCl <30 mL/min): Use with caution; monitor closely as pharmacokinetics may be altered.
Hepatic Adjusment: Mild to moderate impairment: No specific adjustment needed. Severe impairment: Use with caution.
Instruction: For subcutaneous use only. Administer daily into the abdominal wall, thigh, or upper arm. Rotate injection sites. The solution should be clear. Reconstitute immediately before use if using lyophilized powder (some brands). Use aseptic technique.

⚠️ Contraindications

Hypersensitivity to triptorelin, other GnRH agonists, or any excipients
Pregnancy (Category X - see special populations)
Breastfeeding
Undiagnosed abnormal vaginal bleeding
Patients with conditions exacerbated by hypoestrogenism (e.g., severe osteoporosis where risk outweighs benefit)

🔬 Mechanism of Action

Triptorelin is a potent agonist of pituitary GnRH receptors. Initial administration causes a transient surge in the secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the anterior pituitary. With continuous daily administration, it leads to receptor downregulation and desensitization of the gonadotropic cells. This results in a profound suppression of LH and FSH secretion, which in turn leads to a marked reduction in the production of testosterone from the testes and estrogen from the ovaries.

🤕 Side Effects

Hot flushes (flashes)
Increased sweating (hyperhidrosis)
Headache
Injection site reactions (pain, erythema, itching, swelling)
Decreased libido
Erectile dysfunction (in males)
Vaginal dryness, dyspareunia (in females)
Amenorrhea
Fatigue
Mood swings, emotional lability
Initial transient worsening of symptoms (bone pain, urinary issues) due to flare effect

🤰 Special Populations

Pregnancy: CATEGORY X. Contraindicated. May cause fetal harm. Can cause spontaneous abortion. Women of childbearing potential must use non-hormonal contraception during and for at least 2-3 months after therapy. A pregnancy test must be confirmed negative before initiation.

Lactation: Contraindicated. It is not known if triptorelin is excreted in human milk, but due to the potential for serious adverse reactions in the nursing infant, breastfeeding must be discontinued during therapy.

Alcohol: No known direct interaction. However, alcohol may exacerbate side effects like hot flushes, dizziness, and mood changes. Patients should be advised to limit or avoid alcohol.

Driving: May cause fatigue, dizziness, visual disturbances, or syncope (rarely). Patients should be cautioned about operating machinery or driving until they know how the drug affects them.

🔄 Drug Interactions

Androgen Receptor Antagonists (e.g., Bicalutamide, Flutamide): Concomitant use during initial weeks blunts the 'flare' effect in prostate cancer. Synergistic therapeutic effect. Major (Therapeutic)
Drugs that Prolong QT Interval (e.g., Class Ia/III antiarrhythmics, certain antipsychotics, antibiotics): Additive risk of QT prolongation and cardiac arrhythmias. Androgen deprivation may also contribute. Major
Corticosteroids (e.g., Dexamethasone, Prednisolone): May alter metabolism of triptorelin. High doses can suppress pituitary function, potentially altering response. Moderate
Hormonal Contraceptives or HRT: May interfere with the intended hormonal suppression. Generally contraindicated in conditions like endometriosis during therapy. Major
Drugs affecting Pituitary Function (e.g., Dopamine agonists, Somatostatin analogues): Potential unpredictable effects on gonadotropin axis. Moderate

🔁 Alternatives to Decapeptyl SR (Brand Originator - in other markets; daily formulation not commonly marketed in India)

Same composition (Triptorelin (0.5mg/ml)), different brands:

Triptogard Triptocept Trelin Triptolet