Dosing & Uses
Dosage Forms & Strengths
tablet
- 120mg
Prostate Cancer
Indicated for advanced prostate cancer
Day 1 loading dose: 360 mg PO
Maintenance dose: 120 mg PO qDay
Dosage Modifications
Renal impairment
- Mild-to-severe (CrCl 15-89 mL/min): No dosage adjustment required
- End-stage renal disease with or without hemodialysis: Not studied
Hepatic impairment
- Mild-to-moderate (Child-Pugh A or B): No dosage adjustment required
- Severe (Child-Pugh C): Not studied
P-gp inhibitors
- Avoid coadministration; if unable to avoid, take relugolix first and separate dosing by at least 6 hr
- May briefly interrupt relugolix treatment for up to 2 weeks if a short course of treatment with a P-gp inhibitor is required
- If treatment interrupted for >7 days, resume relugolix with 360 mg loading dose on the first day, followed by 120 mg/day
Combined P-gp and strong CYP3A inducers
- Avoid coadministration; if unable to avoid, increase relugolix dose to 240 mg qDay; resume 120 mg qDay after discontinuing the strong P-gp/CYP3A inducer
Dosing Considerations
Correct electrolyte abnormalities
Consider periodic ECG and electrolyte monitoring
Males with female partners of reproductive potential should use effective contraception
Not indicated
Interactions
Interaction Checker
No Results

Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor

Contraindicated (0)
Serious - Use Alternative (0)
Monitor Closely (1)
- gallium Ga 68 PSMA-11
relugolix will decrease the level or effect of gallium Ga 68 PSMA-11 by unspecified interaction mechanism. Modify Therapy/Monitor Closely. Androgen deprivation therapy and other therapies targeting the androgen pathway may result in changes in the uptake of gallium Ga 68 PSMA-11 in prostate cancer. The effect of ADT on the performance of gallium Ga 68 PSMA-11 is unknown.
Minor (0)
Adverse Effects
>10%
All grades
- Hot flush (54%)
- Glucose increased (44%)
- Triglycerides increased (35%)
- Musculoskeletal pain (30%)
- Hemoglobin decreased (28%)
- ALT increased (27%)
- Fatigue (26%)
- AST increased (18%)
- Diarrhea (12%)
- Constipation (12%)
1-10%
All grades
- Increased weight (<10%)
- Insomnia (<10%)
- Gynecomastia (<10%)
- Hyperhidrosis (<10%)
- Depression (<10%)
- Decreased libido (<10%)
Grade 3-4
- Glucose increased (2.9%)
- Triglycerides increased (2%)
- Musculoskeletal pain (1.1%)
<1%
Grade 3-4
- Hot flush
- Fatigue
- Diarrhea
- ALT increased
- Hemoglobin increased
Postmarketing Reports
Immune system disorders: Hypersensitivity, including angioedema and urticaria
Warnings
Contraindications
None
Cautions
Based animal studies and mechanism of action, fetal harm may occur
Therapy suppresses pituitary gonadal system; results of diagnostic tests conducted during and after treatment may be affected; monitor therapeutic effect of relugolix by measuring serum concentrations of prostate specific antigen (PSA) periodically; if PSA increases, measure serum testosterone concentrations
Hypersensitivity reactions, including pharyngeal edema and other serious cases of angioedema, reported; advise patients who experience any symptoms of hypersensitivity to temporarily discontinue therapy and promptly seek medical care; discontinue therapy for severe hypersensitivity reactions and manage as clinically indicated
QT/QTc interval prolongation
- Androgen deprivation therapy may prolong QT/QTc interval
- Consider benefits and risks in patients with congenital long QT syndrome, congestive heart failure, or frequent electrolyte abnormalities, and those taking drugs known to prolong QT interval
- Correct electrolyte abnormalities
- Consider periodic ECG and electrolyte monitoring
Drug interaction overview
- CYP enzymes: Substrate of CYP3A (primarily) and CYP2C8 (minor)
- Transporter systems: Substrate of P-gp; inhibitor of BCRP and P-gp
-
P-gp inhibitors
- Avoid coadministration
- Coadministration increases relugolix AUC and peak plasma concentration; if unable to avoid, adjust time between dosing relugolix and the P-gp inhibitor
-
Combined P-gp and strong CYP3A inducers
- Avoid coadministration
- Coadministration decreases relugolix AUC and peak plasma concentration; if unable to avoid, adjust relugolix dose
Pregnancy & Lactation
Pregnancy
Based on findings in animals and mechanism of action, can cause fetal harm and loss of pregnancy when administered to pregnant females
Human data are unavailable
Animal studies
- Administration to pregnant rabbits during organogenesis caused embryofetal lethality at maternal exposures that were 0.3 times the human exposure at the recommended dose of 120 mg daily based on AUC
Contraception
- Males with female partners of reproductive potential: Use effective contraception during treatment and for 2 weeks after last dose
Infertility
- Based on findings in animals and mechanism of action, may impair fertility in males of reproductive potential
Lactation
Data are unavailable on presence in human milk, effects on breastfed children, or effects on milk production
Relugolix and/or its metabolites were present in milk of lactating rats at concentrations up to 10-fold higher than in plasma at 2 hr post dose
Pregnancy Categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available.Pharmacology
Mechanism of Action
Gonadotropin-releasing hormone (GnRH) receptor antagonist; binds to and blocks GnRH receptors in the anterior pituitary gland
Blocking GnRH receptors decreases the release of gonadotropins (ie, luteinizing hormone, follicle stimulating hormone), thereby decreasing the downstream production of testosterone by the testes in men
Absorption
Absolute bioavailability: ~12%
Peak plasma time: 2.25 hr
Peak plasma concentration
- 360 mg: 215 ng/mL
- 120 mg: 70 ng/mL
AUC
- 360 mg: 985 nghr/mL
- 120 mg: 407 nghr/mL
Distribution
Protein bound: 68-71%; albumin (primarily), alpha1-acid glycoprotein (less extent)
Blood/plasma ratio: 0.78
Metabolism
Metabolized primarily by CYP3A and to lesser extent by CYP2C8 in vitro
Elimination
Half-life: 25 hr; terminal half-life 60.8 hr
Total clearance: 29.4 L/hr
Renal clearance: 8 L/hr
Excretion: Feces (81%; 4.2 unchanged); urine (4.1%; 2.2 unchanged)
Administration
Oral Administration
Take at approximately the same time each day
May take with or without food
Swallow tablets whole; do not crush or chew
Patients treated with GnRH receptor agonists and antagonists for prostate cancer is usually continued upon development of nonmetastatic or metastatic castration-resistant prostate cancer
Missed dose
- Take missed dose as soon as remembered
- Dose missed by >12 hours: Do not take missed dose; resume with next scheduled dose
- Treatment interrupted for >7 days: Restart with 360-mg loading dose on first day, and then continue 120 mg qDay
Storage
Store at room temperature; not to exceed 30ºC (86ºF)
Dispense in original container only
For bottles, keep container tightly closed after first opening
Images
Formulary
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