Myfembree Tablets
WARNING: This drug may raise the chance of blood clots, a stroke, or a heart attack. Talk with the doctor.Do not take this drug if you have or have ever had a blood clot or have been told you are at risk of getting a blood clot.Smoking cigarettes while using this drug raises the chance of severe heart and blood-related side effects. This chance is raised with age (mainly older than 35 years of age). It is also raised with the number of cigarettes smoked. It is strongly advised not to smoke. Do not use this drug if you smoke and are older than 35 years of age.If you have high blood pressure, talk with your doctor. This drug must not be used in people who have high blood pressure that is not controlled. @ COMMON USES: It is used in people who have not been through menopause to control heavy menstrual bleeding caused by uterine fibroids or to help manage pain caused by endometriosis. If you have been given this drug for some other reason, talk with the doctor.
Drug Class
Gonadotropin-releasing hormone (GnRH) receptor antagonist with add-back therapy
Pharmacologic Class
GnRH receptor antagonist; Estrogen; Progestin
Pregnancy Category
Not applicable (Contraindicated)
FDA Approved
May 2021
DEA Schedule
Not Controlled
Overview
What is this medicine?
Myfembree is a daily tablet used to treat heavy menstrual bleeding caused by uterine fibroids and moderate to severe pain from endometriosis. It works by lowering certain hormones in your body, and it also contains small amounts of estrogen and progestin to help manage potential side effects like bone loss and hot flashes.
How to Use This Medicine
Taking Your Medication Correctly
To get the most benefit from your medication, follow your doctor's instructions carefully. Read all the information provided to you and follow the instructions closely. Take your medication at the same time every day, with or without food. If you're a female patient, start taking this medication during the first 7 days of your menstrual cycle. Continue taking your medication as directed by your doctor or healthcare provider, even if you're feeling well.
It's also important to note that some oral medications may need to be taken at a different time than this medication. Consult with your doctor or pharmacist to determine if you need to adjust the timing of any of your other medications.
Storing and Disposing of Your Medication
Store your medication at room temperature in a dry place, avoiding the bathroom. Keep all medications in a safe location, out of the reach of children and pets. When disposing of unused or expired medications, do not flush them down the toilet or pour them down the drain unless instructed to do so. Instead, check with your pharmacist for guidance on the best disposal method or explore drug take-back programs in your area.
What to Do If You Miss a Dose
If you miss a dose, take it as soon as you remember on the same day. However, if you don't remember until the next day, skip the missed dose and resume your regular schedule. Do not take two doses on the same day to make up for the missed dose.
To get the most benefit from your medication, follow your doctor's instructions carefully. Read all the information provided to you and follow the instructions closely. Take your medication at the same time every day, with or without food. If you're a female patient, start taking this medication during the first 7 days of your menstrual cycle. Continue taking your medication as directed by your doctor or healthcare provider, even if you're feeling well.
It's also important to note that some oral medications may need to be taken at a different time than this medication. Consult with your doctor or pharmacist to determine if you need to adjust the timing of any of your other medications.
Storing and Disposing of Your Medication
Store your medication at room temperature in a dry place, avoiding the bathroom. Keep all medications in a safe location, out of the reach of children and pets. When disposing of unused or expired medications, do not flush them down the toilet or pour them down the drain unless instructed to do so. Instead, check with your pharmacist for guidance on the best disposal method or explore drug take-back programs in your area.
What to Do If You Miss a Dose
If you miss a dose, take it as soon as you remember on the same day. However, if you don't remember until the next day, skip the missed dose and resume your regular schedule. Do not take two doses on the same day to make up for the missed dose.
Lifestyle & Tips
- Take Myfembree at approximately the same time each day.
- Do not take Myfembree if you are pregnant or trying to become pregnant, as it can harm a fetus. Use effective non-hormonal contraception during treatment and for one week after stopping Myfembree.
- Be aware of the increased risk of blood clots (thromboembolic events). Discuss any personal or family history of blood clots with your doctor.
- Stop taking Myfembree and seek immediate medical attention if you experience symptoms of a blood clot (e.g., sudden severe headache, chest pain, shortness of breath, sudden vision changes, pain/swelling in leg).
- Inform your doctor about all medications, supplements, and herbal products you are taking, especially St. John's Wort or certain antibiotics, as they can interact with Myfembree.
- Maintain adequate calcium and vitamin D intake for bone health.
- Regular exercise can help maintain bone density.
Available Forms & Alternatives
Available Strengths:
Dosing & Administration
Adult Dosing
Standard Dose:
Relugolix 40 mg, Estradiol 1 mg, Norethindrone acetate 0.5 mg orally once daily
Dose Range:
40 - 40 mg
Condition-Specific Dosing:
Uterine Fibroids (heavy menstrual bleeding):
One tablet (Relugolix 40 mg, Estradiol 1 mg, Norethindrone acetate 0.5 mg) orally once daily.
Endometriosis (moderate to severe pain):
One tablet (Relugolix 40 mg, Estradiol 1 mg, Norethindrone acetate 0.5 mg) orally once daily.
Pediatric Dosing
Neonatal:
Not established
Infant:
Not established
Child:
Not established
Adolescent:
Not established (Safety and efficacy not established in pediatric patients. Use is not indicated before menarche.)
Dose Adjustments
Renal Impairment:
Mild:
No adjustment needed
Moderate:
No adjustment needed
Severe:
No adjustment needed
Dialysis:
No adjustment needed
Hepatic Impairment:
Mild:
No adjustment needed
Moderate:
Not recommended (Relugolix exposure may increase)
Severe:
Contraindicated
Pharmacology
Mechanism of Action
Myfembree is a combination product containing relugolix, estradiol, and norethindrone acetate. Relugolix is a non-peptide, orally active gonadotropin-releasing hormone (GnRH) receptor antagonist that competitively binds to and blocks GnRH receptors in the anterior pituitary gland. This action decreases the release of gonadotropins (luteinizing hormone [LH] and follicle-stimulating hormone [FSH]), leading to a reduction in ovarian estradiol production. The addition of estradiol and norethindrone acetate (add-back therapy) is intended to mitigate the bone mineral density loss and vasomotor symptoms associated with the hypoestrogenic state induced by relugolix, while maintaining the therapeutic effect on uterine fibroids or endometriosis.
Pharmacokinetics
Absorption:
Bioavailability:
Relugolix: ~12%; Estradiol: ~5% (oral); Norethindrone: ~64%
Tmax:
Relugolix: 2.5-4 hours; Estradiol: 6-8 hours; Norethindrone: 1-2 hours
FoodEffect:
Relugolix: High-fat meal decreases Cmax by 46% and AUC by 25%. Estradiol/Norethindrone: Minimal clinically significant effect.
Distribution:
Vd:
Relugolix: 191 L; Estradiol: ~18 L/kg; Norethindrone: ~4 L/kg
ProteinBinding:
Relugolix: 68-71%; Estradiol: ~98% (to albumin and SHBG); Norethindrone: ~61% (to albumin and SHBG)
CnssPenetration:
Limited for Relugolix; Estradiol and Norethindrone can cross the blood-brain barrier.
Elimination:
HalfLife:
Relugolix: 61.5 hours; Estradiol: ~13-17 hours; Norethindrone: ~8-11 hours
Clearance:
Relugolix: 3.6 L/h (oral); Estradiol: High hepatic clearance; Norethindrone: High hepatic clearance
ExcretionRoute:
Relugolix: Primarily feces (82%), minor urine (4.2%); Estradiol: Urine (as conjugates); Norethindrone: Urine and feces (as metabolites)
Unchanged:
Relugolix: ~10% in urine; Estradiol: <10%; Norethindrone: <1%
Pharmacodynamics
OnsetOfAction:
Suppression of LH/FSH and estradiol levels typically within 2-4 weeks.
PeakEffect:
Maximal suppression of estradiol levels typically within 4-8 weeks.
DurationOfAction:
Effects on hormone levels persist as long as treatment continues; return to baseline hormone levels typically within 4-8 weeks after discontinuation.
Safety & Warnings
BLACK BOX WARNING
THROMBOEMBOLIC DISORDERS
Myfembree is contraindicated in women with a history of arterial or venous thromboembolic (TE) events or a thrombogenic valvular heart disease. Myfembree increases the risk of TE events, including stroke, myocardial infarction, deep vein thrombosis, and pulmonary embolism. Discontinue Myfembree if a TE event occurs. Discontinue Myfembree at least 1 week before and for at least 2 weeks after major surgery or prolonged immobilization due to increased risk of TE events. If medically appropriate, consider prophylactic anticoagulation during prolonged immobilization.
Myfembree is contraindicated in women with a history of arterial or venous thromboembolic (TE) events or a thrombogenic valvular heart disease. Myfembree increases the risk of TE events, including stroke, myocardial infarction, deep vein thrombosis, and pulmonary embolism. Discontinue Myfembree if a TE event occurs. Discontinue Myfembree at least 1 week before and for at least 2 weeks after major surgery or prolonged immobilization due to increased risk of TE events. If medically appropriate, consider prophylactic anticoagulation during prolonged immobilization.
Side Effects
Serious Side Effects: Seek Medical Help Immediately
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you experience any of the following symptoms, contact your doctor or seek medical attention right away:
Allergic Reaction: Rash, hives, itching, red, swollen, blistered, or peeling skin with or without fever, wheezing, tightness in the chest or throat, trouble breathing, swallowing, or talking, unusual hoarseness, or swelling of the mouth, face, lips, tongue, or throat.
Liver Problems: Dark urine, tiredness, decreased appetite, upset stomach or stomach pain, light-colored stools, vomiting, or yellow skin or eyes.
High Blood Pressure: Severe headache or dizziness, passing out, or changes in eyesight.
Gallbladder Problems: Pain in the upper right belly area, right shoulder area, or between the shoulder blades; yellow skin or eyes; fever with chills; bloating; or severe upset stomach or vomiting.
High Blood Sugar: Confusion, feeling sleepy, unusual thirst or hunger, frequent urination, flushing, fast breathing, or breath that smells like fruit.
Neurological Symptoms: Weakness on one side of the body, trouble speaking or thinking, changes in balance, drooping on one side of the face, or blurred eyesight.
Eyesight Changes: Changes in vision, loss of vision, bulging eyes, or changes in how contact lenses feel.
Bone Pain: Pain in the bones.
Breast Changes: Lump in the breast, breast pain or soreness, or nipple discharge.
Mood Changes: New or worsening behavior or mood changes, such as depression or thoughts of suicide.
Blood Clots: Chest pain or pressure, coughing up blood, shortness of breath, swelling, warmth, numbness, changes in color, or pain in a leg or arm; or trouble speaking or swallowing.
Additional Serious Side Effects for Women with Uterine Fibroids:
If you have uterine fibroids, you may experience fibroids coming out through the vagina, either partially or completely. Seek medical help immediately if you experience severe cramping, stomach pain, or vaginal bleeding.
Other Possible Side Effects
Not everyone will experience side effects, and many people may only have mild side effects. However, if you experience any of the following side effects, contact your doctor or seek medical attention if they bother you or do not go away:
Hot flashes
Excessive sweating
Night sweats
Flushing
Changes in menstrual period
Decreased interest in sex
Headache
Upset stomach
Tooth pain
Back pain
Joint pain
Feeling dizzy, tired, or weak
This is not a comprehensive list of all possible side effects. If you have questions or concerns about side effects, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you experience any of the following symptoms, contact your doctor or seek medical attention right away:
Allergic Reaction: Rash, hives, itching, red, swollen, blistered, or peeling skin with or without fever, wheezing, tightness in the chest or throat, trouble breathing, swallowing, or talking, unusual hoarseness, or swelling of the mouth, face, lips, tongue, or throat.
Liver Problems: Dark urine, tiredness, decreased appetite, upset stomach or stomach pain, light-colored stools, vomiting, or yellow skin or eyes.
High Blood Pressure: Severe headache or dizziness, passing out, or changes in eyesight.
Gallbladder Problems: Pain in the upper right belly area, right shoulder area, or between the shoulder blades; yellow skin or eyes; fever with chills; bloating; or severe upset stomach or vomiting.
High Blood Sugar: Confusion, feeling sleepy, unusual thirst or hunger, frequent urination, flushing, fast breathing, or breath that smells like fruit.
Neurological Symptoms: Weakness on one side of the body, trouble speaking or thinking, changes in balance, drooping on one side of the face, or blurred eyesight.
Eyesight Changes: Changes in vision, loss of vision, bulging eyes, or changes in how contact lenses feel.
Bone Pain: Pain in the bones.
Breast Changes: Lump in the breast, breast pain or soreness, or nipple discharge.
Mood Changes: New or worsening behavior or mood changes, such as depression or thoughts of suicide.
Blood Clots: Chest pain or pressure, coughing up blood, shortness of breath, swelling, warmth, numbness, changes in color, or pain in a leg or arm; or trouble speaking or swallowing.
Additional Serious Side Effects for Women with Uterine Fibroids:
If you have uterine fibroids, you may experience fibroids coming out through the vagina, either partially or completely. Seek medical help immediately if you experience severe cramping, stomach pain, or vaginal bleeding.
Other Possible Side Effects
Not everyone will experience side effects, and many people may only have mild side effects. However, if you experience any of the following side effects, contact your doctor or seek medical attention if they bother you or do not go away:
Hot flashes
Excessive sweating
Night sweats
Flushing
Changes in menstrual period
Decreased interest in sex
Headache
Upset stomach
Tooth pain
Back pain
Joint pain
Feeling dizzy, tired, or weak
This is not a comprehensive list of all possible side effects. If you have questions or concerns about side effects, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- Sudden severe headache, especially with vision changes or weakness
- Sudden chest pain, shortness of breath, or coughing up blood
- Pain, swelling, or warmth in one leg
- Sudden numbness or weakness on one side of the body
- Yellowing of the skin or eyes (jaundice)
- Severe abdominal pain
- Mood changes, depression, or suicidal thoughts
- New or worsening migraine headaches
- Unusual vaginal bleeding
- Signs of an allergic reaction (e.g., rash, itching, swelling, severe dizziness, trouble breathing)
Before Using This Medicine
Before Taking This Medication: Important Information to Share with Your Doctor
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances. Be sure to describe the symptoms you experienced.
Certain health conditions, such as:
+ Blood vessel problems in the brain or heart
+ Atrial fibrillation
+ Endocarditis (a heart infection)
+ History of heart attack or stroke
+ Other heart problems
+ Liver problems
+ Diabetes with complications affecting the kidneys, eyes, nerves, or blood vessels
+ Severe headaches or migraines
+ Osteoporosis (soft, brittle bones)
A history of breast cancer or other cancers that are hormone-sensitive
Unexplained vaginal bleeding
Use of hormone-based birth control methods
Taking rifampin
Pregnancy or potential pregnancy. Note: This medication is contraindicated during pregnancy.
To ensure safe treatment, it is crucial to discuss all of your medications (prescription, over-the-counter, natural products, and vitamins) and health problems with your doctor and pharmacist. This includes:
All prescription and non-prescription medications you are currently taking
Any natural products or vitamins you are using
Existing health problems or conditions
Do not initiate, discontinue, or modify the dosage of any medication without first consulting your doctor to confirm that it is safe to do so with this medication. This list is not exhaustive, and it is your responsibility to verify that it is safe to take this medication with all of your other medications and health conditions.
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances. Be sure to describe the symptoms you experienced.
Certain health conditions, such as:
+ Blood vessel problems in the brain or heart
+ Atrial fibrillation
+ Endocarditis (a heart infection)
+ History of heart attack or stroke
+ Other heart problems
+ Liver problems
+ Diabetes with complications affecting the kidneys, eyes, nerves, or blood vessels
+ Severe headaches or migraines
+ Osteoporosis (soft, brittle bones)
A history of breast cancer or other cancers that are hormone-sensitive
Unexplained vaginal bleeding
Use of hormone-based birth control methods
Taking rifampin
Pregnancy or potential pregnancy. Note: This medication is contraindicated during pregnancy.
To ensure safe treatment, it is crucial to discuss all of your medications (prescription, over-the-counter, natural products, and vitamins) and health problems with your doctor and pharmacist. This includes:
All prescription and non-prescription medications you are currently taking
Any natural products or vitamins you are using
Existing health problems or conditions
Do not initiate, discontinue, or modify the dosage of any medication without first consulting your doctor to confirm that it is safe to do so with this medication. This list is not exhaustive, and it is your responsibility to verify that it is safe to take this medication with all of your other medications and health conditions.
Precautions & Cautions
Important Warnings and Cautions
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. Your doctor may advise you to stop taking this drug before certain surgical procedures, and will instruct you on when to resume taking it after the surgery or procedure.
Monitoring and Precautions
Regular blood pressure checks are crucial, as this medication can cause high blood pressure. Follow your doctor's instructions for monitoring your blood pressure.
Women taking this medication should have regular breast exams and gynecology check-ups, and perform breast self-exams as directed by their doctor.
If you will be immobile for extended periods, such as during long trips, bedrest after surgery, or illness, discuss this with your doctor, as prolonged immobility may increase your risk of blood clots.
Lab Tests and Health Conditions
This medication may affect certain laboratory tests, so it is crucial to inform all your healthcare providers and lab workers that you are taking this drug.
If you have diabetes (high blood sugar), consult your doctor, as this medication may increase your blood sugar levels. Monitor your blood sugar levels as directed by your doctor.
High cholesterol and triglyceride levels have been associated with this medication. If you have high cholesterol or triglycerides, discuss this with your doctor.
Bone Health and Calcium Supplementation
Long-term use of this medication may lead to loss of bone density, which may not be reversible after stopping the medication. Follow your doctor's instructions for bone density checks. Take calcium and vitamin D supplements as directed by your doctor.
Duration of Use and Potential Side Effects
Do not take this medication for longer than prescribed by your doctor. Hair loss and thinning are potential side effects, and it is unclear if hair growth will return to normal after stopping the medication.
Menstrual Changes and Pregnancy
This medication may cause changes in menstrual bleeding, including cessation of periods, which can make it difficult to determine if you are pregnant. Be aware of other signs of pregnancy, such as tender breasts, weight gain, and upset stomach.
This medication can harm an unborn baby or cause pregnancy loss. A pregnancy test will be conducted before starting this medication to confirm that you are not pregnant. Use a non-hormone birth control method, such as condoms, to prevent pregnancy while taking this medication and for at least 1 week after the last dose. Do not use hormone-based birth control methods, including birth control pills, while taking this medication.
If you suspect you are pregnant or have a positive pregnancy test, contact your doctor immediately.
Breastfeeding
If you are breastfeeding, consult your doctor to discuss any potential risks to your baby.
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. Your doctor may advise you to stop taking this drug before certain surgical procedures, and will instruct you on when to resume taking it after the surgery or procedure.
Monitoring and Precautions
Regular blood pressure checks are crucial, as this medication can cause high blood pressure. Follow your doctor's instructions for monitoring your blood pressure.
Women taking this medication should have regular breast exams and gynecology check-ups, and perform breast self-exams as directed by their doctor.
If you will be immobile for extended periods, such as during long trips, bedrest after surgery, or illness, discuss this with your doctor, as prolonged immobility may increase your risk of blood clots.
Lab Tests and Health Conditions
This medication may affect certain laboratory tests, so it is crucial to inform all your healthcare providers and lab workers that you are taking this drug.
If you have diabetes (high blood sugar), consult your doctor, as this medication may increase your blood sugar levels. Monitor your blood sugar levels as directed by your doctor.
High cholesterol and triglyceride levels have been associated with this medication. If you have high cholesterol or triglycerides, discuss this with your doctor.
Bone Health and Calcium Supplementation
Long-term use of this medication may lead to loss of bone density, which may not be reversible after stopping the medication. Follow your doctor's instructions for bone density checks. Take calcium and vitamin D supplements as directed by your doctor.
Duration of Use and Potential Side Effects
Do not take this medication for longer than prescribed by your doctor. Hair loss and thinning are potential side effects, and it is unclear if hair growth will return to normal after stopping the medication.
Menstrual Changes and Pregnancy
This medication may cause changes in menstrual bleeding, including cessation of periods, which can make it difficult to determine if you are pregnant. Be aware of other signs of pregnancy, such as tender breasts, weight gain, and upset stomach.
This medication can harm an unborn baby or cause pregnancy loss. A pregnancy test will be conducted before starting this medication to confirm that you are not pregnant. Use a non-hormone birth control method, such as condoms, to prevent pregnancy while taking this medication and for at least 1 week after the last dose. Do not use hormone-based birth control methods, including birth control pills, while taking this medication.
If you suspect you are pregnant or have a positive pregnancy test, contact your doctor immediately.
Breastfeeding
If you are breastfeeding, consult your doctor to discuss any potential risks to your baby.
Overdose Information
Overdose Symptoms:
- Nausea
- Vomiting
- Breast tenderness
- Abdominal pain
- Drowsiness/fatigue
- Vaginal bleeding (in females)
What to Do:
There is no specific antidote. Treatment is symptomatic and supportive. Contact a poison control center or seek emergency medical attention. Call 1-800-222-1222.
Drug Interactions
Contraindicated Interactions
- Strong P-glycoprotein (P-gp) inducers (e.g., rifampin, carbamazepine, phenytoin, St. John's Wort) - significantly reduce relugolix exposure.
- Certain strong CYP3A inducers (e.g., rifampin, carbamazepine, phenytoin, St. John's Wort) - may reduce estradiol/norethindrone efficacy.
Major Interactions
- P-gp inhibitors (e.g., cyclosporine, erythromycin, azithromycin, verapamil, itraconazole, ketoconazole, ritonavir, grapefruit juice) - increase relugolix exposure. Co-administration requires taking Myfembree at least 6 hours before the P-gp inhibitor.
- Strong CYP3A inhibitors (e.g., ketoconazole, itraconazole, clarithromycin, ritonavir) - may increase estradiol/norethindrone exposure, increasing risk of adverse effects.
- Thyroid hormone replacement therapy (e.g., levothyroxine) - estrogen component may increase thyroid-binding globulin, requiring increased thyroid hormone dose.
Moderate Interactions
- Moderate CYP3A inducers (e.g., bosentan, efavirenz, modafinil) - may reduce estradiol/norethindrone efficacy.
- Moderate CYP3A inhibitors (e.g., diltiazem, fluconazole) - may increase estradiol/norethindrone exposure.
- Lamotrigine - estrogen component may decrease lamotrigine levels, potentially leading to loss of seizure control.
- Warfarin/Oral anticoagulants - estrogens may affect coagulation factors, requiring INR monitoring.
- Antidiabetic agents - estrogens may decrease glucose tolerance, requiring adjustment of antidiabetic therapy.
Minor Interactions
- Ascorbic acid (Vitamin C) - may increase estrogen levels.
- Acetaminophen - may increase estrogen levels.
Monitoring
Baseline Monitoring
Pregnancy test
Rationale: Myfembree is contraindicated in pregnancy.
Timing: Prior to initiation of treatment.
Bone Mineral Density (BMD)
Rationale: Relugolix can cause dose-dependent bone loss. Add-back therapy mitigates this, but baseline is important.
Timing: Prior to initiation of treatment, especially if risk factors for bone loss are present.
Lipid profile
Rationale: Estrogens can affect lipid metabolism.
Timing: Prior to initiation of treatment.
Blood pressure
Rationale: Estrogens can cause an increase in blood pressure.
Timing: Prior to initiation of treatment.
Liver function tests (LFTs)
Rationale: Hepatic impairment is a contraindication or requires caution. Estrogens can affect liver function.
Timing: Prior to initiation of treatment.
Personal and family history of thromboembolic events, cardiovascular disease, or stroke
Rationale: Myfembree carries a Black Box Warning for thromboembolic events.
Timing: Prior to initiation of treatment.
Routine Monitoring
Bone Mineral Density (BMD)
Frequency: Annually, or as clinically indicated, especially if treatment extends beyond 12 months.
Target: Maintain stable BMD or minimize loss.
Action Threshold: Significant bone loss (e.g., >2-3% decrease from baseline or T-score < -2.5) may warrant treatment discontinuation or re-evaluation.
Blood pressure
Frequency: Periodically, as clinically indicated.
Target: Normal limits.
Action Threshold: Significant or sustained elevation may require intervention or discontinuation.
Lipid profile
Frequency: Periodically, as clinically indicated.
Target: Within normal limits or individualized targets.
Action Threshold: Significant adverse changes may require intervention.
Symptoms of thromboembolic events (e.g., leg pain/swelling, chest pain, shortness of breath, sudden severe headache, vision changes)
Frequency: Ongoing patient education and monitoring.
Target: Absence of symptoms.
Action Threshold: Immediate medical attention required if symptoms occur.
Symptom Monitoring
- Signs/symptoms of thromboembolic events (e.g., deep vein thrombosis, pulmonary embolism, stroke, myocardial infarction)
- Changes in mood or suicidal ideation
- New or worsening headache/migraine
- Vision changes
- Jaundice or signs of liver dysfunction
- Breast lumps or changes
- Abnormal vaginal bleeding
- Symptoms of allergic reaction
Special Patient Groups
Pregnancy
Contraindicated. Myfembree can cause early pregnancy loss and is not for use in pregnant women. Patients should use effective non-hormonal contraception during treatment and for one week after discontinuation.
Trimester-Specific Risks:
First Trimester:
High risk of early pregnancy loss; potential for fetal harm.
Second Trimester:
Not applicable, as use is contraindicated.
Third Trimester:
Not applicable, as use is contraindicated.
Lactation
Not recommended. Relugolix, estradiol, and norethindrone are present in human milk. Due to the potential for serious adverse reactions in a breastfed infant, including bone mineral density effects and effects on hormone levels, advise women not to breastfeed during treatment and for 2 days after the last dose.
Infant Risk:
L4 (Possibly hazardous)
Pediatric Use
Safety and efficacy have not been established in pediatric patients. Myfembree is not indicated for use before menarche.
Geriatric Use
Clinical studies did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Myfembree is not indicated in postmenopausal women.
Clinical Information
Clinical Pearls
- Myfembree is a combination product designed to treat heavy menstrual bleeding associated with uterine fibroids and moderate to severe pain associated with endometriosis, while mitigating the hypoestrogenic side effects of GnRH antagonism.
- It is crucial to counsel patients on the Black Box Warning regarding thromboembolic events. A thorough patient history, including personal and family history of clotting disorders, is essential before initiation.
- Patients must use effective non-hormonal contraception during treatment and for one week after stopping Myfembree, as it is contraindicated in pregnancy.
- Advise patients to take Myfembree at least 6 hours before any P-gp inhibitors (e.g., cyclosporine, erythromycin, grapefruit juice) to avoid significant increases in relugolix exposure.
- Bone mineral density should be monitored, especially in patients with risk factors for bone loss or those on long-term therapy.
- Myfembree is not a contraceptive and does not protect against sexually transmitted infections.
Alternative Therapies
- For Uterine Fibroids: GnRH agonists (e.g., leuprolide), progestin-only therapies (e.g., oral progestins, levonorgestrel IUD), tranexamic acid, NSAIDs, surgical options (myomectomy, hysterectomy), uterine artery embolization.
- For Endometriosis: GnRH agonists (e.g., leuprolide), oral contraceptives, progestin-only therapies, NSAIDs, surgical options (laparoscopy with excision/ablation).
Cost & Coverage
Average Cost:
$1500 - $2000 per 30 tablets
Insurance Coverage:
Specialty Tier or Tier 3/4 (requires prior authorization, step therapy)
General Drug Facts
If your symptoms or health issues persist or worsen, it's essential to contact your doctor for further guidance. To ensure your safety, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so be sure to check with your pharmacist for more information. If you have any questions or concerns about this medication, don't hesitate to reach out to your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek medical attention. When seeking help, be prepared to provide details about the medication taken, the amount, and the time it occurred.