DegarelixvsLeuprolide

Molecular Formula

C₈₂H₁₀₃ClN₁₈O₁₆

Molecular Weight

1632.3 Da

Half-Life

~53 days (median terminal half-life)

Bioavailability

100% (subcutaneous injection)

CAS Number

214766-78-6

Molecular Formula

C₅₉H₈₄N₁₆O₁₂

Molecular Weight

1209.4 g/mol

Half-Life

Approximately 2-6 hours (varies by route of administration)

Bioavailability

~95% (subcutaneous injection)

CAS Number

74381-53-6

Common

• Mild discomfort at treatment site
• Injection site pain (28% of patients)
• Injection site redness or erythema (17%)
• Hot flashes (26% experience them)
• Increased liver enzymes and gamma-glutamyltransferase (10%)
• Weight gain (9%)
• Hypertension or elevated blood pressure (6%)
• Back pain (6%)
• Chills (5%)
• Constipation (5%)
• Urinary tract infection (5%)
• Injection site swelling (6%)
• Injection site induration or hardness (4%)
• Decreased sex drive and erectile dysfunction
• Gynecomastia (breast tissue growth)
• Testicular atrophy (shrinking)

Serious

• Severe allergic reaction

Common

• Hot flashes (very common in men)
• Decreased libido and erectile dysfunction
• Injection site pain or swelling
• Nausea
• Fatigue
• Mood changes or depression
• Joint or muscle pain
• Headaches
• Dizziness
• Thinning hair
• Decreased bone density (osteoporosis with long-term use)
• QT prolongation (rare but serious cardiac effect)
• Tumor flare (temporary worsening of cancer symptoms in first weeks)
• Severe allergic reactions
• Spinal cord compression risk in men with metastatic disease

Serious

• Severe allergic reaction

Evidence Level

Strong human trials (Phase 3 or FDA approved)

FDA Status

FDA approved for this use

Safety Overview

Degarelix is an FDA-approved GnRH antagonist with safety data from Phase 3 trials and post-market use in prostate cancer treatment. Advantages over GnRH agonists include absence of testosterone flare, allowing rapid castration without initial symptom surge. Primary safety concerns relate to intentional hormone suppression: hot flashes occur in 40-70% of men, erectile dysfunction in 40-60%, bone density loss of 2-3% annually, and cardiovascular risks in patients >65 years. Injection site reactions (erythema, induration) occur in 20-30% of patients and can be severe in a small percentage. Liver enzyme elevations appear in 5% of patients. QT prolongation potential exists and cardiac monitoring is recommended in susceptible patients.

Contraindications

• xHistory of severe hypersensitivity to degarelix
• xAllergy to any product components (mannitol or other additives)
• xActive untreated severe anaphylaxis risk

Evidence Level

Strong human trials (Phase 3 or FDA approved)

FDA Status

FDA approved for this use

Safety Overview

Leuprolide (Lupron) is an FDA-approved GnRH agonist with 35+ years of clinical safety data involving millions of patients in oncology and endocrinology. The critical safety issue is the initial 5-7 day flare effect—temporary surge in FSH/LH causing symptom worsening before hormone suppression begins—particularly dangerous for prostate cancer patients (flare can cause urinary obstruction or spinal cord compression). Bone density loss is a dose-dependent long-term risk in both men and women requiring monitoring. Injection site reactions, hot flushes, and initial hypogonadal symptoms are expected and typically transient.

Contraindications

• xPregnancy or breastfeeding (teratogenic)
• xUndiagnosed vaginal bleeding
• xActive bone metastases with spinal cord compression (increased fracture risk)
• xAllergy to GnRH agonists or components
• xSevere cardiovascular disease with QT prolongation risk