Relugolix + Estradiol + Norethindrone
Indications
Relugolix + Estradiol + Norethindrone is used for:
Uterine Fibroids
Adult Dose
Uterine Fibroids
Oral
Tablet
Fixed-dose combination tablet indicated for management of heavy menstrual bleeding associated with uterine leiomyomas (fibroids) in premenopausal women
1 tablet (relugolix 40 mg/estradiol 1 mg/norethindrone 0.5 mg) PO once daily
Start as early as possible after onset of menses but no later than 7 days after menses has started.
Recommended total duration of treatment is 24 months.
Hepatic impairment
Contraindicated
Use of estradiol (E2) in patients with hepatic impairment is expected to increase exposure to E2 and increase the risk of E2-associated adverse reactions
Child Dose
Renal Dose
Renal impairment
Estradiol and norethindrone: Not studied
Relugolix
Mild-to-severe (CrCl 15-89 mL/min): No dosage adjustment required
End-stage renal disease with or without hemodialysis: Not studied
Administration
May take with or without food at approximately the same time
Contra Indications
Pregnancy
Osteoporosis
Current or history of breast cancer or other hormone-sensitive malignancies
Hepatic impairment or disease
Undiagnosed abnormal uterine bleeding
Hypersensitivity to drug or its components
High risk of arterial, venous thrombotic, or thromboembolic disorder
Precautions
Thromboembolic disorders and vascular events
Estrogen and progestin combination products, including relugolix/estradiol/norethindrone, increase the risk of thrombotic or thromboembolic disorders including pulmonary embolism (PE), deep vein thrombosis (DVT), stroke, and myocardial infarction (MI), especially in women at increased risk for these events.
Immediately discontinue if a hypersensitivity reaction occurs
Studies among estrogen users suggest a small increased relative risk of developing gallbladder disease; discontinue therapy if signs or symptoms of gallbladder disease or jaundice occur; assess the risk-benefit of continuing therapy for women with a history of cholestatic jaundice associated with past estrogen use or with pregnancy
New or worsening hypertension occurred; continue to monitor blood pressure (BP) and stop therapy if BP rises significantly
Women may experience amenorrhea or a reduction in the amount, intensity, or duration of menstrual bleeding, which may delay the ability to recognize pregnancy; perform pregnancy testing if pregnancy is suspected and discontinue treatment if pregnancy is confirmed
Based on animal studies and mechanism of action, early pregnancy loss may occur
Uterine fibroid prolapse and uterine fibroid expulsion reported; advise women with known or suspected submucosal uterine fibroids about the possibility of uterine fibroid prolapse or expulsion and to contact their physician if severe bleeding and/or cramping occur during treatment
Discontinue therapy if a hormone-sensitive malignancy is diagnosed;
Bone loss
Bone mineral density (BMD) loss may occur; may be greater with increasing duration of use and may not be completely reversible after stopping treatment.
Depression, mood disorders, and suicidal ideation
Depression (including depression, mood swings, and depressed mood), irritability, anxiety, and suicidal ideation occurred.
Pregnancy-Lactation
Pregnancy
Contraindicated
Based on findings from animal studies and its mechanism of action, early pregnancy loss may occur
Discontinue if pregnancy occurs during treatment
Limited human data with use in pregnant females are insufficient to evaluate for a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes
Perform pregnancy testing if pregnancy is suspected during treatment and discontinue treatment if pregnancy is confirmed
Contraception for females of reproductive potential
Use effective nonhormonal contraception during treatment and for 1 week following discontinuation
Avoid concomitant use of hormonal contraceptives
Use of estrogen-containing hormonal contraceptives may increase the risk of estrogen-associated adverse events and is expected to decrease the efficacy of relugolix/estradiol/norethindrone
Animal data
Oral administration of relugolix in pregnant rabbits during organogenesis resulted in spontaneous abortion and total litter loss at relugolix exposures about half those at the maximum recommended human dose (MRHD) of 40 mg
In both rabbits and rats, no fetal malformations were present at any dose level tested, which were associated with relugolix exposures of about half and ~300x exposures in women at the MRHD, respectively
Lactation
There are no data on presence of relugolix or its metabolites in human milk, effects on the breastfed children, or effects on milk production
Relugolix was detected in milk of lactating rats
When a drug is present in animal milk, it is likely that the drug will be present in human milk
Detectable amounts of estrogen and progestin have been identified in the breast milk of women receiving estrogen plus progestin therapy and can reduce milk production in breastfeeding women
Reduction can occur at any time but is less likely to occur once breastfeeding is well established
Interactions
Side Effects
Side effects of Relugolix + Estradiol + Norethindrone :
>10%
Hot flush, hyperhidrosis, or night sweats (10.6%)
1-10%
Increased total cholesterol 130 to <160 mg/dL (9.3%)
Abnormal uterine bleeding (6.3%)
Alopecia (3.5%)
Libido decreased (3.1%)
Irritability (2-3%)
Dyspepsia (2-3%)
Breast cyst (2-3%)
Depression (2.4%)
Irritability (2.4%)
Increased total cholesterol >240 mg/dL (1.7%)
Increased total cholesterol 160 to <190 mg/dL (1.5%)
Anxiety (1.2%)
<1%
Low trauma fractures (defined as a fall from standing height or less) (0.6%)
Increased total cholesterol ≥190 mg/dL (0.5%)
Uterine myoma expulsion (0.4%)
Uterine leiomyoma (prolapse) (0.4%)
Frequency Not Defined
Suicidal ideation
Mode of Action
Relugolix
Gonadotropin-releasing hormone (GnRH) receptor antagonist; binds to and blocks GnRH receptors in the anterior pituitary gland
Blocking GnRH receptors decreases the release of gonadotropins (ie, luteinizing hormone, follicle-stimulating hormone), thereby decreasing the downstream production of estrogen and progesterone by the ovaries in women
Estradiol and norethindrone
Estradiol: Addition of exogenous estradiol may reduce the increase in bone resorption and resultant bone loss that can occur due to a decrease in circulating estrogen concentrations from relugolix alone
Norethindrone: Protect the uterus from the potential adverse endometrial effects of unopposed estrogen