Mifepristone (Korlym)


Mifepristone (Korlym) is used to treat hyperglycemia (high blood sugar) in people with a certain type of Cushing’s syndrome in which the body makes too much cortisol (a hormone) and who have failed surgery or cannot have surgery to treat this condition. Mifepristone is in a class of medications called cortisol receptor blockers. It works by blocking the activity of cortisol.

Mifepristone is also available as another product (Mifeprex) that is used alone or in combination with another medication to end an early pregnancy. This monograph only gives information about mifepristone (Korlym) used to control hyperglycemia in people with a certain type of Cushing’s syndrome. If you are using mifepristone to terminate a pregnancy, read the monograph entitled mifepristone (Mifeprex), which has been written about this product.

Side Effects Of Mifepristone (Korlym)

Mifepristone may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

  • headache
  • vomiting
  • dry mouth
  • diarrhea
  • constipation
  • joint or muscle pain
  • swelling of the hands, feet, ankles, or lower legs
  • rash
  • itching

Some side effects can be serious. If you experience any of these symptoms, call your doctor immediately or get emergency medical treatment:

  • nausea
  • loss of appetite
  • dizziness or lightheadedness
  • unusual tiredness or weakness
  • nervousness or irritability
  • shakiness
  • sweating
  • muscle weakness, aches, or cramps
  • rapid, irregular, or pounding heartbeats
  • unexpected vaginal bleeding or spotting
  • shortness of breath

Mifepristone may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

Warnings & Precautions

Before taking mifepristone:

  • tell your doctor if you are allergic to mifepristone, any other medications, or any of the ingredients in mifepristone tablets. Ask your pharmacist or check the manufacturer’s patient information for a list of the ingredients.
  • tell your doctor if you are taking any of the following medications or have taken them in the last two weeks: corticosteroids such as betamethasone (Celestone), budesonide (Entocort), cortisone (Cortone), dexamethasone (Decadron, Dexpak, Dexasone, others), fludrocortisone (Floriner), hydrocortisone (Cortef, Hydrocortone), methylprednisolone (Medrol, Meprolone, others), prednisolone (Prelone, others), prednisone (Deltasone, Meticorten, Sterapred, others), and triamcinolone (Aristocort, Azmacort); medications that suppress the immune system such as cyclosporine (Neoral, Sandimmune), sirolimus (Rapamune), and tacrolimus (Prograf); dihydroergotamine (D.H.E. 45, Migranal); ergotamine (Ergomar, in Cafergot, in Migergot); fentanyl (Duragesic); lovastatin (Mevacor); pimozide (Orap); quinidine (Quinidex); and simvastatin (Zocor). Your doctor will probably tell you not to take mifepristone if you are taking one or more of these medications.
  • tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or have taken in the last two weeks. Be sure to mention any of the following: anticoagulants (‘blood thinners’) such as warfarin (Coumadin); antifungals such as itraconazole (Sporanox), ketoconazole (Nizoral), posaconazole (Noxafil), or voriconazole (Vfend); aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Advil, Motrin) and naproxen (Aleve, Naprosyn); bupropion (Wellbutrin); ciprofloxacin (Cipro); clarithromycin (Biaxin); conivaptan (Vaprisol); diltiazem (Cardizem); erythromycin (E.E.S., E-Mycin, Erythrocin); fluvastatin (Lescol); hormonal contraceptives such as birth control pills, implants, patches, rings, or injections; medications for hepatitis C such as boceprevir (Victrelis) and telaprevir (Incivek); medications for HIV or AIDS such as amprenavir (Agenerase), atazanavir (Reyataz), efavirenz (Sustiva), fosamprenavir (Lexiva), indinavir (Crixivan), lopinavir and ritonavir combination (Kaletra), nelfinavir (Viracept), ritonavir (Norvir), and saquinavir (Fortovase, Invirase); medications for seizures such as carbamazepine (Tegretol), phenobarbital (Luminal, Solfoton), phenytoin (Dilantin); medications for tuberculosis such as rifabutin (Mycobutin), rifampin (Rifadin, Rimactane, in Rifamate, in Rifater) and rifapentine (Priftin); nefazodone (Serzone); repaglinide (Prandin); telithromycin (Ketek); and verapamil (Calan, Isoptin, others). Many other medications may also interact with mifepristone, so be sure to tell your doctor about all the medications you are taking, even those that do not appear on this list. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
  • tell your doctor what herbal products you are taking, especially St. John’s Wort.
  • tell your doctor if you have ever had an organ transplant or if you have or ever had thyroid disease. If you are a woman and have not had surgery to remove your uterus, tell your doctor if you have or have ever had unexplained vaginal bleeding, endometrial hyperplasia (overgrowth of the lining of the uterus), or endometrial cancer (cancer of the lining of your uterus). Your doctor will probably tell you not to take mifepristone.
  • tell your doctor if you have or have ever had heart failure, a prolonged QT interval (a rare heart problem that may cause irregular heartbeat, fainting, or sudden death), low potassium in your blood, adrenal insufficiency(a condition in which the adrenal glands do not produce enough of certain hormones needed for important body functions), a bleeding disorder, or liver, kidney, or heart disease.
  • tell your doctor if you are breast-feeding.

Dosage Of Mifepristone (Korlym)

Mifepristone comes as a tablet to take by mouth. It is usually taken once a day with a meal. Take mifepristone at around the same time every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take mifepristone exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Swallow the tablets whole; do not split, chew, or crush them. Tell your doctor or pharmacist if you are not able to swallow the tablets whole.

Your doctor will start you on a low dose of mifepristone and gradually increase your dose, not more often than once every 2 to 4 weeks. If you stop taking mifepristone, call your doctor. Your doctor may have to start you again on the lowest dose of mifepristone and gradually increase your dose.

Mifepristone can control your condition but does not cure it. It may take 6 weeks or longer before you feel the full benefit of mifepristone. Continue to take mifepristone even if you feel well.


Before having any laboratory test, tell your doctor and the laboratory personnel that you are taking mifepristone.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.


All information has been provided courtesy of MedLinePlus from the National Library of Medicine and from the FDA.