🔬 Androgen Deprivation Therapy (Leuprolide) Simulator

Baseline Hypothalamic-Pituitary-Gonadal Testosterone Control

Placeholder lead — the intact HPG axis maintains steady testosterone output.

• ~500 ng/dL: Baseline serum testosterone (Placeholder short caption text here.)
• ~10 mIU/mL: Baseline LH (Placeholder short caption text here.)
• 100%: GnRH receptor density (Placeholder short caption text here.)
• ~90 min: GnRH pulse frequency (Placeholder short caption text here.)

Hypothalamic GnRH pulse generator

Placeholder body text — pulsatile GnRH release drives the axis.

Pituitary LH secretion

Placeholder body text — gonadotrophs respond with LH pulses.

Testicular Leydig cell output

Placeholder body text — LH stimulates Leydig cell testosterone synthesis.

Leuprolide Injection — Initial GnRH Receptor Agonism

Placeholder lead — leuprolide first behaves as a potent GnRH-receptor agonist.

• GnRH agonist: Drug class (Placeholder short caption text here.)
• Depot injection: Formulation (Placeholder short caption text here.)
• Higher: Receptor affinity vs native GnRH (Placeholder short caption text here.)
• Hours: Onset of stimulation (Placeholder short caption text here.)

Depot pharmacokinetics

Placeholder body text — sustained-release depot maintains drug exposure.

Receptor occupancy surge

Placeholder body text — leuprolide occupies GnRH receptors continuously.

Why agonism precedes suppression

Placeholder body text — continuous stimulation differs from pulsatile signaling.

Testosterone Flare — The First 1-2 Weeks

Placeholder lead — LH and testosterone transiently spike above baseline.

• ~800-900 ng/dL: Flare peak testosterone (Placeholder short caption text here.)
• Day 5-8: Typical flare peak day (Placeholder short caption text here.)
• ~5-6× baseline: Flare LH peak (Placeholder short caption text here.)
• Bone metastases: Clinical concern group (Placeholder short caption text here.)

LH surge kinetics

Placeholder body text — LH rises sharply within the first days.

Testicular response lag

Placeholder body text — testosterone follows LH with a short delay.

Symptom-worsening risk

Placeholder body text — flare can transiently worsen bone-metastasis symptoms.

Continued Exposure — Pituitary Receptor Downregulation

Placeholder lead — sustained stimulation desensitizes and downregulates receptors.

• ~20%: Receptor density by day 21 (Placeholder short caption text here.)
• Internalization: Mechanism (Placeholder short caption text here.)
• Progressive decline: LH trend after peak (Placeholder short caption text here.)
• Falling toward castrate: Testosterone trend (Placeholder short caption text here.)

Receptor internalization

Placeholder body text — GnRH receptors are pulled from the membrane.

Uncoupled signal transduction

Placeholder body text — remaining receptors signal less effectively over time.

Falling gonadotropin output

Placeholder body text — LH secretion progressively declines despite continued drug.

Sustained Castration-Level Testosterone Suppression

Placeholder lead — testosterone reaches and sustains castrate levels.

• <50 ng/dL: Castrate threshold (Placeholder short caption text here.)
• ~4 weeks: Time to castrate levels (Placeholder short caption text here.)
• Continued dosing: Maintenance (Placeholder short caption text here.)
• Anti-androgen co-therapy: Flare mitigation (Placeholder short caption text here.)

Sustained suppression

Placeholder body text — castrate testosterone persists with ongoing therapy.

Anti-androgen co-treatment

Placeholder body text — peripheral receptor blockade blunts flare-related risk.

Clinical monitoring

Placeholder body text — testosterone and symptoms are tracked through week four.