Relugolix

Relugolix is a prescription medication used for the treatment of advanced prostate cancer. 

• Relugolix is available under the following different brand names: Orgovyx

Common side effects of Relugolix include:

• Hot flushes
• Increased blood sugar levels
• Increased blood fat (triglyceride) levels
• Muscle and joint pain
• Decreased blood hemoglobin levels
• Increased liver enzymes
• Tiredness
• Constipation
• Diarrhea

Serious side effects of Relugolix include:

• dizziness
• fainting
• feeling that the heart is pounding or racing (palpitations)
• chest pain

Rare side effects of Relugolix include:

• none 

Seek medical care or call 911 at once if you have the following serious side effects:

• Severe headache, confusion, slurred speech, arm or leg weakness, trouble walking, loss of coordination, feeling unsteady, very stiff muscles, high fever, profuse sweating, or tremors;
• Serious eye symptoms such as sudden vision loss, blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights;
• Serious heart symptoms include fast, irregular, or pounding heartbeats; fluttering in the chest; shortness of breath; sudden dizziness, lightheadedness, or passing out. 

This is not a complete list of side effects and other serious side effects or health problems that may occur because of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.

Adult dosage

Tablet

• 120 mg

Prostate Cancer

Adult dosage

• Day 1 loading dose: 360 mg Orally
• Maintenance dose: 120 mg orally once a day

Dosage Considerations – Should be Given as Follows: 

• See “Dosages”

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

• Relugolix has severe interactions with no other drugs.
• Relugolix has serious interactions with no other drugs.
• Relugolix has moderate interactions with the following drugs
  • gallium Ga 68 PSMA-11
• Relugolix has minor interactions with no other drugs.

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this product, tell your doctor or pharmacist about all your products. Keep a list of all your medications with you and share this information with your doctor and pharmacist. Check with your healthcare professional or doctor for additional medical advice, or if you have health questions or concerns.

Contraindications

None

Effects of drug abuse

• None

Short-Term Effects

• See “What Are Side Effects Associated with Using Relugolix?”

Long-Term Effects

• See “What Are Side Effects Associated with Using Relugolix?”

Cautions

• Based on animal studies and mechanism of action, fetal harm may occur
• Therapy suppresses the pituitary-gonadal system; results of diagnostic tests conducted during and after treatment may be affected; monitor the therapeutic effect of relugolix by measuring serum concentrations of prostate-specific antigen (PSA) periodically; if PSA increases, measure serum testosterone concentrations
• 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 it, adjust the 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 and Lactation

• 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
• Contraception
  • Males with female partners of reproductive potential: Use effective contraception during treatment and for 2 weeks after the 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 the presence in human milk, effects on breastfed children, or effects on milk production
  • Relugolix and/or its metabolites were present in the milk of lactating rats at concentrations up to 10-fold higher than in plasma at 2 hours post-dose