Category/Class

Gonadotropin-releasing hormone (GnRH) receptor antagonist

Mechanism of Action

The drug binds to GnRH receptors, which reduces the release (https://www.fda.gov/news-events/press-announcements/fda-approves-first-oral-hormone-therapy-treating-advanced-prostate-cancer) of luteinizing hormone, follicle-stimulating hormone, and testosterone.

Indication

Adults with advanced prostate cancer

Dosing

Given as an initial loading dose of 360 mg on the first day, then 120 mg daily (https://www.accessdata.fda.gov/drugsatfda_docs/label/2020/214621s000lbl.pdf)

Administration

Tablets should be taken orally, with or without food, without chewing or crushing. If patients miss a dose (https://www.accessdata.fda.gov/drugsatfda_docs/label/2020/214621s000lbl.pdf) by more than 12 hours, do not take the missed dose; resume with the next scheduled dose.

Adverse Reactions

More than 10%–15% of patients in clinical trials experienced hot flashes, fatigue, elevated glucose, elevated triglycerides, musculoskeletal pain, decreased hemoglobin, elevated liver enzymes, constipation, and diarrhea. Less than 10% of patients reported (https://www.accessdata.fda.gov/drugsatfda_docs/label/2020/214621s000lbl.pdf) weight gain, insomnia, gynecomastia, hyperhidrosis, depression, and decreased libido.

Warnings

Increased risk (https://www.accessdata.fda.gov/drugsatfda_docs/label/2020/214621s000lbl.pdf) of prolonged QT interval and embryo-fetal toxicity

Nursing Considerations

Relugolix can suppress the pituitary gonadal system; monitor laboratory testing during and after therapy. Monitor its therapeutic effect with periodic prostate-specific antigen testing. Because of the potential effect on QT/ATc interval, patients may require electrocardiogram and electrolyte monitoring. For treatment interruptions (https://www.accessdata.fda.gov/drugsatfda_docs/label/2020/214621s000lbl.pdf) longer than seven days, resume relugolix with a loading dose of 360 mg on the first day, then 120 mg daily.

Drug-Drug and Drug-Food Interactions

Avoid using in combination with P-gp inhibitors and CYP3A inducers. P-gp inhibitors can increase (https://www.accessdata.fda.gov/drugsatfda_docs/label/2020/214621s000lbl.pdf) its maximum concentration, whereas CYP3A inducers can decrease it.

Patient Education

Men with female partners of reproductive potential should use effective contraception during treatment and for two weeks after the last dose. Patients should be counseled (https://www.accessdata.fda.gov/drugsatfda_docs/label/2020/214621s000lbl.pdf) about the potential for impaired fertility.

Gero-Oncology Considerations

No overall differences in safety or effectiveness were observed (https://www.accessdata.fda.gov/drugsatfda_docs/label/2020/214621s000lbl.pdf) in clinical trials in patients aged 65 years and older compared to younger patients.

Patient Assistance

Call 833-674-6899 for a patient support program.