relugolix

Contraindicated in:

Hypersensitivity.

Use Cautiously in:

Congenital long QT syndrome, HF, electrolyte abnormalities, or concurrent use of QT interval prolonging drugs;
Rep: Men with female partners of reproductive potential.

Adv. Reactions/Side Effects ⬆ ⬇

CV: QT interval prolongation

Derm: hot flush, ↑sweating

Endo: hyperglycemia, gynecomastia

GI: ↑liver enzymes, constipation, diarrhea

GU: ↓fertility, ↓libido

Hemat: anemia

Metab: hypertriglyceridemia, weight gain

MS: pain

Neuro: fatigue, depression, insomnia

Misc: HYPERSENSITIVITY REACTIONS (INCLUDING ANGIOEDEMA)

Interactions ⬆ ⬇

Drug-drug:

Concurrent use of QT interval prolonging drugs may ↑ risk of QT interval prolongation and torsades de pointes.
P-glycoprotein (P-gp) inhibitors may ↑ levels and risk of toxicity; avoid concurrent use. If concurrent use unavoidable, administer relugolix first and then administer P-gp inhibitor ≥6 hr later. If P-gp inhibitor only administered for ≤2 wk, may interrupt relugolix therapy.
Combined P-gp and strong CYP3A4 inducers may ↓ levels and effectiveness; avoid concurrent use. If concurrent use unavoidable, ↑ relugolix dose.

Availability ⬆ ⬇

Route/Dosage ⬆ ⬇

PO (Adults ): 360 mg (loading dose) on Day 1; then 120 mg once daily (maintenance dose) starting on Day 2 and thereafter. Concurrent use of combined P-gp and strong CYP3A inducer: ↑maintenance dose to 240 mg once daily. If combined P-gp and strong CYP3A4 inducer discontinued, ↓ maintenance dose to 120 mg once daily.

US Brand Names ⬆ ⬇

Action ⬆ ⬇

Reversibly binds to a gonadotropin-releasing hormone receptors in the pituitary gland, causing a decrease in the release of gonadotropins and testosterone.

Therapeutic effects:

Achievement and maintenance of serum testosterone suppression to medical castration levels.

Classifications ⬆ ⬇

Therapeutic Classification: antineoplastics

Pharmacologic Classification: gnrh antagonist

Pharmacokinetics ⬆ ⬇

Absorption: 12% absorbed following oral administration.

Distribution: Unknown.

Metabolism/Excretion: Primarily metabolized in the liver via the CYP3A4 isoenzyme (and to a lesser extent by CYP2C8). Primarily excreted in feces (81%; 4.2% as unchanged drug), with 4.1% excreted in urine (2.2% as unchanged drug).

Half-Life: 61 hr.

Time/Action Profile ⬆ ⬇

(↓ in testosterone levels)

ROUTE	ONSET	PEAK	DURATION
PO	within 1 wk	unknown	48 wk

Patient/Family Teaching ⬆ ⬇

Explain purpose and side effects of relugolix . If a dose is missed, it should taken as soon as remembered; if a dose is missed >12 hr, do not take the missed dose and resume treatment with the next scheduled dose. Advise patient to read Patient Information before starting therapy.
Side effects may include flushing of the skin, hot flashes, musculoskeletal pain, fatigue, constipation, diarrhea, ↑ weight, ↓ sex drive, and erectile dysfunction.
Warn patient to report symptoms of arrhythmias and QT prolongation (fast heartbeat, skipped beats, palpitations, dizziness, light-headedness, trouble breathing, faintness).
Advise patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult health care professional before taking other medications.
Rep: May cause fetal harm; advise men with female partners of reproductive potential to use effective contraception during treatment and for 2 wk after last dose.

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Indications ⬇

Contraind./Precautions ⬆ ⬇