Is QT interval monitoring necessary in patients taking Orgovyx (relugolix)?

From the Guidelines

Monitoring the QT interval is not routinely necessary for patients taking Orgovyx (relugolix), but caution is advised in patients with pre-existing QT prolongation or those taking other QT-prolonging medications. According to the most recent and highest quality study, 1, the QT interval should be calculated by either of the two most standardized formulas, Bazett’s QT/(RR1/2) or Fridericia’s QT/ (RR1/3), and comparative measurements during treatment should all utilize the same chosen method. However, Orgovyx has not been associated with QT interval prolongation at clinically relevant doses and does not require specific electrocardiogram (ECG) monitoring in most patients. Some key points to consider when monitoring the QT interval include:

• Patients with a history of QT prolongation, relevant cardiac disease, treated with QT-prolonging drugs, bradycardia, thyroid dysfunction, or electrolyte abnormalities should be monitored by repeated 12-lead ECG, as stated in 1.
• Conditions known to provoke torsade de pointes, especially hypokalaemia and extreme bradycardia, should be avoided in patients with drug-induced QT prolongation, as mentioned in 1.
• Exposure to other QT-prolonging drugs should be minimized in patients treated with potentially QT-prolonging chemotherapy, as recommended in 1. It is essential to note that Orgovyx is an oral gonadotropin-releasing hormone (GnRH) receptor antagonist used primarily for advanced prostate cancer treatment, and its cardiovascular safety profile is generally favorable, with QT prolongation not being a significant concern based on clinical trials, as discussed in 1. As with any medication, patients should report any symptoms such as palpitations, dizziness, or fainting, which might warrant further cardiac evaluation.

From the FDA Drug Label

1. 1 QT/QTc Interval Prolongation Androgen deprivation therapy, such as ORGOVYX may prolong the QT/QTc interval. Providers should consider whether the benefits of androgen deprivation therapy outweigh the potential risks in patients with congenital long QT syndrome, congestive heart failure, or frequent electrolyte abnormalities and in patients taking drugs known to prolong the QT interval Electrolyte abnormalities should be corrected. Consider periodic monitoring of electrocardiograms and electrolytes [see Clinical Pharmacology (12.2)].

Monitoring of QT interval is recommended in patients taking Orgovyx, especially in those with congenital long QT syndrome, congestive heart failure, or frequent electrolyte abnormalities, and in patients taking drugs known to prolong the QT interval.

• Key considerations:
  • Congenital long QT syndrome
  • Congestive heart failure
  • Frequent electrolyte abnormalities
  • Patients taking drugs known to prolong the QT interval
• Recommendation: Consider periodic monitoring of electrocardiograms and electrolytes 2.

From the Research

Monitoring the QT Interval in Patients Taking Orgovyx

• The QT interval is a measure of the time it takes for the heart's ventricles to prepare for a new beat, and prolongation of this interval can increase the risk of torsades de pointes, a potentially life-threatening cardiac arrhythmia 3, 4.
• Orgovyx (relugolix) is a gonadotropin-releasing hormone receptor antagonist used to treat advanced prostate cancer, and it may cause prolongation of the QT or QTc interval 5.
• Patients taking Orgovyx should be monitored for QT interval prolongation, as this can increase the risk of torsades de pointes 3, 6.
• The risk of QT interval prolongation should be assessed in patients who are about to begin taking Orgovyx, and patients with risk factors such as female sex, age >65 years, and uncorrected electrolyte disturbances should be closely monitored 6.
• Electrocardiogram (ECG) monitoring can be used to detect QT interval prolongation, and it is recommended that patients taking high-risk QT interval-prolonging drugs, including Orgovyx, undergo regular ECG monitoring 7, 6.

Key Considerations for Monitoring the QT Interval

• The QT interval should be measured using a standardized method, and the corrected QT (QTc) interval should be calculated to account for changes in heart rate 3, 6.
• Patients taking Orgovyx should be monitored for signs and symptoms of QT interval prolongation, including dizziness, syncope, and palpitations 4.
• The risk of QT interval prolongation should be minimized by avoiding the use of other QT-prolonging medications and by correcting any underlying electrolyte disturbances 6, 4.