What are the adverse effects of Orgovyx (relugolix)?

Adverse Effects of Orgovyx (Relugolix)

Orgovyx (relugolix) commonly causes hot flashes, increased weight, decreased sex drive, and erectile dysfunction as its primary adverse effects, with potential for QT interval prolongation and hypersensitivity reactions requiring monitoring. 1

Common Adverse Effects

• Hot flashes/flushing - The most frequently reported adverse effect, occurring in a significant percentage of patients taking Orgovyx 1, 2
• Fatigue and asthenia - Common complaints that may impact quality of life 1, 2
• Gastrointestinal effects - Including constipation and diarrhea 1, 2
• Musculoskeletal effects - Myalgia (muscle pain) is commonly reported 2
• Metabolic changes - Increased blood sugar levels and increased blood fat (triglyceride) levels 1
• Hematologic effects - Decreased blood hemoglobin levels 1
• Hepatic effects - Increased liver enzymes may occur 1
• Sexual function effects - Decreased libido and erectile dysfunction 1
• Weight gain - Has been reported in patients taking Orgovyx 1

Serious Adverse Effects

QT/QTc Interval Prolongation

• Androgen deprivation therapy with Orgovyx may prolong the QT interval 1, 3
• Patients should be monitored for signs and symptoms of QT prolongation including:
  • Dizziness
  • Fainting
  • Palpitations
  • Chest pain 1
• Patients with pre-existing cardiac conditions or long QT syndrome require particular attention 1

Hypersensitivity Reactions

• Can include severe reactions such as angioedema 1
• Patients with previous severe hypersensitivity to relugolix or any components should not take Orgovyx (contraindicated) 1
• Patients experiencing hypersensitivity symptoms should discontinue Orgovyx and seek immediate medical attention 1

Timing of Adverse Events

• The majority of adverse effects occur within the first 30 days after starting Orgovyx 2
• The median time to onset of adverse events is approximately 60 days 2

Cardiovascular Considerations

• Relugolix may have a more favorable cardiac safety profile compared to LHRH agonists like leuprolide 4, 5
• Data from the HERO study demonstrated a reduced risk for major adverse cardiovascular events compared to leuprolide 5
• This may be particularly relevant for patients with pre-existing cardiovascular disease 5

Special Populations and Considerations

Pregnancy and Fertility

• Orgovyx can be harmful to a developing fetus and can cause pregnancy loss 1
• Male patients with female partners of reproductive potential should use effective contraception during treatment and for 2 weeks after the last dose 1
• May cause infertility, which should be discussed with patients prior to initiating treatment 1

Renal Impairment

• No specific dose adjustments are mentioned for renal impairment in the FDA label, unlike some other medications that require dose modifications 1

Monitoring Recommendations

• Regular monitoring of:
  • Cardiac symptoms, especially in those with pre-existing heart conditions 1
  • Complete blood counts to monitor for anemia 1
  • Liver function tests to monitor for elevated enzymes 1
  • Blood glucose and lipid levels 1
  • Weight changes 1

Comparison to Other Therapies

• As an oral GnRH antagonist, relugolix offers advantages over injectable LHRH agonists, including:
  • No initial testosterone surge (which can cause clinical flare in some patients) 4, 5
  • Potentially lower risk of cardiovascular events 4, 5
  • Rapid testosterone recovery upon discontinuation 5
  • Convenience of oral administration 4

Patient Counseling

• Patients should be informed about the common side effects related to androgen deprivation 1
• Patients should report any signs of allergic reactions or cardiac symptoms immediately 1
• Medication should be taken at approximately the same time each day 1
• If a dose is missed, it should be taken as soon as remembered if within 12 hours; otherwise, the missed dose should be skipped 1