mifepristone (Rx)

Brand and Other Names:Mifeprex, Korlym, more...ru486
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Dosing & Uses


Dosage Forms & Strengths


  • 200mg (Mifeprex)
  • 300mg (Korlym)

Pregnancy Termination

Mifeprex: Indicated for the medical termination of intrauterine pregnancy through 70 days gestation in combination with misoprostol

Day 1: 200 mg of mifepristone PO as a single dose under physician supervision

Days 2-3: 800 mcg of misoprostol buccally once as a single dose; must be administered a minimum of 24-hr and a maximum of 48-hr following mifeprostone dose on day 1 (see Administration)

Days 7-14

  • Must return for follow-up visit to confirm complete termination has occurred by medical history, clinical examination, hCG testing, or ultrasonographic scan
  • If complete expulsion has not occurred, but the pregnancy is not ongoing, women may be treated with another dose of misoprostol 800 mcg buccally with follow-up in ~7 days
  • Lack of bleeding following treatment usually indicates failure; however, prolonged or heavy bleeding is not proof of a complete abortion
  • Surgical evacuation is recommended to manage ongoing pregnancies after medical abortion

Dosing considerations

  • Pregnancy is dated from the first day of the last menstrual period
  • Duration of pregnancy may be determined from menstrual history and clinical examination
  • Assess the pregnancy by ultrasonographic scan if the duration of pregnancy is uncertain or if ectopic pregnancy is suspected
  • Remove any intrauterine device (IUD) before treatment
  • Because most women will expel the pregnancy within 2-24 hr of taking misoprostol, discuss with the patient an appropriate location for her to be when she takes the misoprostol, taking into account that expulsion could begin within 2 hr of administration

Cushing Syndrome

Korlym: Indicated to control hyperglycemia secondary to hypercortisolism in adults with endogenous Cushing syndrome who have type 2 diabetes mellitus or glucose intolerance and have failed surgery or are not candidates for surgery

300 mg PO qDay initially; may dose to a maximum of 1200 mg/day, but should not exceed 20 mg/kg/day

Increase in dose should not occur more frequently than every 2-4 weeks and should be based on assessment of glucose control, antidiabetic medication requirements, insulin levels and psychiatric symptoms

Dosage Modifications (Korlym)

Coadministration with strong CYP3A inhibitors: Not to exceed 300 mg/day

Renal impairment: No change in initial dose; limit maximum dose to 600 mg PO qDay

Hepatic impairment

  • Mild-to-moderate: No change in initial dose; limit maximum dose to 600 mg PO qDay
  • Severe: Do not use

Ovarian Cancer (Orphan)

Korlym: Orphan designation for treatment of ovarian cancer


  • Corcept Therapeutics, Inc; 149 Commonwealth Drive; Menlo Park, California 94025

Safety and efficacy not established



Interaction Checker

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            Adverse Effects

            >10% (Mifeprex)

            Abdominal pain, cramping (96%)

            Uterine cramping (83%)

            Nausea (43-61%)

            Headache (2-31%)

            Vomiting (1-26%)

            Diarrhea (12-20%)

            Dizziness (1-12%)

            >10% (Korlym)

            Fatigue (48%)

            Nausea (48%)

            Headache (44%)

            Endometrial hypertrophy (38%)

            Hypokalemia (34%)

            Arthralgia (30%)

            Vomiting (26%)

            Peripheral edema (26%)

            Hypertension (24%)

            Dizziness (22%)

            Decreased appetite (20%)

            Abnormal thyroid function test (18%)

            Xerostomia (18%)

            Back pain (16%)

            Dyspnea (16%)

            Myalgia (14%)

            Pain (14%)

            Sinusitis (14%)

            Nasopharyngitis (12%)

            Extremity pain (12%)

            Diarrhea (12%)

            Postmarketing reports

            • Angioedema

            1-10% (Mifeprex)

            Fatigue (10%)

            Back pain (9%)

            Decreased hemoglobin >2 g/dL (6%)

            Uterine hemorrhage (5%)

            Viral infection (4%)

            Dyspepsia (3%)

            Insomnia (3%)

            Rigors (3%)

            Vaginitis (3%)

            Anemia (2%)

            Anxiety (2%)

            Fainting (2%)

            Leg pain (2%)

            Leukorrhea (2%)

            Pelvic pain (2%)

            Sinusitis (2%)

            Weakness (2%)

            1-10% (Korlym)

            Constipation (10%)

            Somnolence (10%)

            Anorexia (10%)

            Anxiety (10%)

            Gastroesophageal reflux (5-10%)

            Abdominal pain (5-10%)

            Increased triglycerides (5-10%)

            Hypoglycemia (5-10%)

            Insomnia (5-10%)

            Vaginal hemorrhage, metrorrhagia (5-10%)

            General disorders: asthenia, malaise, edema, pitting edema, thirst (5-10%)

            Musculoskeletal and connective tissue disorders: muscular weakness, flank pain, musculoskeletal chest pain (5-10%)

            Adrenal insufficiency (4%)

            Rash (4%)

            Pruritus (4%)



            Black Box Warnings


            • Serious and sometimes fatal infections and bleeding occur very rarely following spontaneous, surgical, and medical abortions
            • Atypical presentation of infection reported; patients with serious bacterial infections (eg, Clostridium sordellii) and sepsis can present without fever, bacteremia or significant findings on pelvic examination following an abortion; very rarely, deaths have been reported in patients who presented without fever, with or without abdominal pain, but with leukocytosis with a marked left shift, tachycardia, hemoconcentration, and general malaise
            • Prolonged heavy bleeding may be a sign of incomplete abortion or other complications that requires prompt medical attention
            • Should be used only with strict adherence to recommended dosages by medically trained personnel who can provide immediate intensive care in acute surgical facilities


            • Potent antiprogestational effects and will result in the termination of pregnancy
            • Pregnancy must therefore be excluded before the initiation of treatment with Korlym, or if treatment is interrupted for more than 14 days in females of reproductive potential
            • Pregnancy must be prevented during treatment and for 1 month after stopping treatment by the use of a nonhormonal medically acceptable method of contraception unless the patient has had a surgical sterilization


            Known hypersensitivity to mifepristone, misoprostol, or other prostaglandins


            • Confirmed or suspected ectopic pregnancy, undiagnosed adnexal mass, or IUD currently in place
            • Chronic adrenal failure or concurrent long-term corticosteroid therapy
            • Hemorrhagic disorders, inherited porphyrias, or concurrent anticoagulant therapy


            • Pregnancy
            • Coadministration with simvastatin or lovastatin and CYP3A substrates with narrow therapeutic range (eg, cyclosporine, dihydroergotamine, ergotamine, fentanyl, pimozide, quinidine, sirolimus, tacrolimus)
            • Patients requiring systemic corticosteroids for serious medical conditions
            • Women with history of unexplained vaginal bleeding
            • Women with endometrial hyperplasia with atypia or endometrial carcinoma



            • A clinical examination or ultrasonographic scan should be performed approximately 14 days after mifepristone administration to confirm termination of pregnancy
            • Preventive measures to suppress formation of anti-Rho(D) antibodies (eg, administration of Rho(D) immune globulin) should be considered in Rho (D)-negative women
            • Women who became pregnant with an IUD in place should be assessed for ectopic pregnancy
            • Use with caution in women <35 years who smoke 10 or more cigarettes daily
            • Any termination of pregnancy, including those resulting from mifepristone use, may result in serious, potentially fatal infections and bleeding (see Black Box Warnings)
            • Available only through a restricted program under a REMS called the Mifeprex REMS Program, because of the risks of serious complications; prescribers must be certified and patients must sign a patient agreement form
            • Must be dispensed to patients only in certain healthcare settings, specifically clinics, medical offices, and hospitals by or under the supervision of a certified prescriber


            • Do not use for treatment of hyperglycemia unrelated to Cushing syndrome
            • Adrenal insufficiency may occur; discontinue therapy if signs or symptoms occur and administer glucocorticoids
            • Hypokalemia should be corrected prior to treatment and monitored for during treatment
            • Women may experience endometrial thickening or unexpected vaginal bleeding; use with caution if patient also has a hemorrhagic disorder or is on anticoagulant therapy
            • Avoid use with QT interval-prolonging drugs or in patients with potassium channel variants resulting in a long QT interval
            • Use of Korlym in patients who receive corticosteroids for other conditions (eg, autoimmune disorders) may lead to exacerbation or deterioration because of Korlym’s glucocorticoid antagonistic effects; for medical conditions in which chronic corticosteroid therapy is life-saving (eg, immunosuppression in organ transplantation), Korlym is contraindicated
            • Coadministration with strong CYP3A inhibitors can increase mifepristone plasma levels significantly; use only when necessary and limit mifepristone dose to 300 mg (see Dosage Modification)

            Pregnancy & Lactation


            Drug contraindicated in pregnancy because use results in pregnancy loss; there are no data that assess risk of birth defects in women exposed to drug during pregnancy

            Available data limited to exposure following a single dose of mifepristone during pregnancy showed a higher rate of major birth defects compared to the general population comparator

            Pregnancy testing

            • Due to its anti-presentational activity, drug causes pregnancy loss; perform pregnancy testing before initiation of treatment or if treatment interrupted for more than 14 days in females of reproductive potential


            • Recommend non-hormonal contraception for duration of treatment and for one month after stopping treatment; drug interferes with effectiveness of hormonal contraceptives

            Animal data

            • Administered to pregnant mice, rats, and rabbits during organogenesis caused pregnancy loss in all species at clinically relevant doses based on body surface area comparisons; inhibition of both endogenous and exogenous progesterone by mifepristone at progesterone receptor results in pregnancy loss; if used during pregnancy or if patient becomes pregnant while taking drug, patient should be apprised of potential hazard to a fetus
            • Estimated risk of fetal loss is elevated in patients with active Cushing’s syndrome (24-30%), and risk of major birth defects is unknown; in the U.S. general population, estimated background risks of major birth defects and miscarriage in clinically recognized pregnancies are 2-4% and 15-20%, respectively


            Drug is present in human milk, however, there are no data on amount of mifepristone in human milk, effects on breastfed infant, or on milk production during long term use of mifepristone; developmental and health benefits of breastfeeding should be considered along with mother’s clinical need for Korlym and any potential adverse effects on breastfed child from drug or from the underlying maternal condition

            To minimize exposure to a breastfed infant, women who discontinue or interrupt treatment may consider pumping and discarding milk during treatment and for 18-21 days (5-6 half-lives) after last dose, before breastfeeding

            Pregnancy Categories

            A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

            B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

            C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

            D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

            X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

            NA: Information not available.



            Mechanism of Action

            Stimulate uterine contractility: antiprogestin; also increases prostaglandins by inhibiting prostaglandin dehydrogenase

            Blocks cortisol receptor binding, and thereby reduces excess cortisol effects (eg, hyperglycemia) associated with endogenous Cushing syndrome


            Peak Plasma Time: 1-2 hr (single dose); 1-4 hr (multiple doses)

            Peak Plasma Concentration: 2-8 hr


            Protein Bound: >99% to alpha-1-acid glycoprotein; 96-99% (active metabolites)

            Distributed to other tissues including CNS


            Extensively metabolized by CYP3A4

            Metabolized to 3 active metabolites, of which 2 are the product of demethylation, while a third active metabolite results from hydroxylation

            In addition to being a CYP3A4 substrate, it also inhibits and induces CYP3A4


            Half-life: 20 hr (single dose); 85 hr (parent drug following multiple doses)

            Excretion: 90% feces



            Oral Administration (Mifeprex)

            200 mg PO once given by a healthcare provider in a clinic, medical office, or hospital followed 24-48 hr later by misoprostol buccal administration

            Buccal administration (misoprostol)

            • Because most women will expel the pregnancy within 2-24 hr of taking misoprostol, discuss with the patient an appropriate location for her to be when she takes the misoprostol, taking into account that expulsion could begin within 2 hr of administration
            • Administer misoprostol 800 mcg buccally within 24-48 hr after taking Mifeprex
            • The effectiveness of the regimen may be lower if misoprostol is administered <24 hr or >48 hr after mifepristone administration
            • Tell the patient to place two 200 mcg misoprostol tablets in each cheek pouch (the area between the cheek and gums) for 30 minutes and then swallow any remnants with water or another liquid
            • During the period immediately following the administration of misoprostol, the patient may need medication for cramps or GI symptoms

            Oral Administration (Korlym)

            Always take with a meal

            Must be taken as a single daily dose

            Swallow tablet whole, do not split, crush, or chew

            Dose reduction or discontinuation may be needed in some clinical situations; if dosage is interrupted, reinitiate at the lowest dose (ie, 300 mg/day)





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            Tier Description
            1 This drug is available at the lowest co-pay. Most commonly, these are generic drugs.
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