Korlym Side Effects Center
Medical Editor: Charles Patrick Davis, MD, PhD
Korlym (mifepristone) is indicated to control high blood sugar levels (hyperglycemia) in adults with endogenous Cushing's syndrome who have type 2 diabetes mellitus or glucose intolerance and have failed surgery or are not candidates for surgery. Korlym is not available as a generic drug. The most common side effects experienced by endogenous Cushing's syndrome patients treated with Korlym in clinical trials were nausea, fatigue, headache, arthralgia, vomiting; swelling of the extremities, dizziness and decreased appetite.
The recommended starting dose of Korlym is 300 mg once daily. Because of risk of renal impairment, 600 mg once daily should not be exceeded. Certain drugs used in combination with Korlym may increase its drug level. Health care professionals must be aware of the potential for drug-drug interactions and adjust dosing or avoid using certain drugs with Korlym. Serious side effects of Korlym include adrenal insufficiency, low potassium levels, vaginal bleeding, and a potential for heart conduction abnormalities. Korlym should never be used by pregnant women. Korlym can cause fetal harm when administered to a pregnant woman because the use of Korlym results in pregnancy loss. If Korlym is used during pregnancy or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to a fetus. Patients should alert their doctors if they are breastfeeding or plan to breastfeed. Korlym passes into breast milk and may harm unborn babies. Patients should decide with their doctors if it's best to take Korlym or to breastfeed. Women should not do both. Safety and effectiveness in the pediatric population has not been established.
Our Korlym to Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
What is Prescribing information?
The FDA package insert formatted in easy-to-find categories for health professionals and clinicians.
Korlym FDA Prescribing Information: Side Effects
Clinical Trials Experience
Because clinical trials are conducted under widely varying conditions, the adverse reaction rates observed cannot be directly compared to rates in other clinical trials and may not reflect the rates observed in clinical practice.
Safety data on the use of Korlym are available from 50 patients with Cushing's syndrome enrolled in an uncontrolled, open-label, multi-center trial (Study 400). Forty-three patients had Cushing's disease and all except one had previously undergone pituitary surgery. Four patients had ectopic ACTH secretion, and three had adrenal carcinoma. Patients were treated for up to 24 weeks. A dose of 300 mg per day was administered for the initial 14 days; thereafter, the dose could be escalated in increments of 300 mg per day based on assessments of tolerability and clinical response. Doses were escalated up to 900 mg per day for patients < 60 kg, or 1200 mg per day for patients > 60 kg.
The most frequently reported adverse reactions (reported in ≥ 20% of patients, regardless of relationship to Korlym) were nausea, fatigue, headache, decreased blood potassium, arthralgia, vomiting, peripheral edema, hypertension, dizziness, decreased appetite, and endometrial hypertrophy. Drug-related adverse events resulted in dose interruption or reduction in study drug in 40% of patients.
The adverse reactions that occurred in ≥ 10% of the Cushing's syndrome patients receiving Korlym, regardless of relationship to Korlym, are shown in Table 1. 7
Table 1: Treatment Emergent Adverse Events Occurring in
≥ 10% of Cushing's Syndrome Patients Receiving Korlym
|Body System/Adverse Reaction||Percent (%) of Patients Reporting Event
(n = 50)
|General disorders and administration/site conditions|
|Nervous system disorders|
|Musculoskeletal and connective tissue disorders|
|Pain in extremity||12|
|Blood potassium decreased||34|
|Thyroid function test abnormal||18|
|Infections and infestations|
|Metabolism and nutrition disorders|
|Reproductive system and breast disorders|
|Respiratory, thoracic, and mediastinal disorders|
|*The denominator was 26 females who had baseline and end-of-trial transvaginal ultrasound|
Reductions in high density lipoprotein-cholesterol (HDL-C) levels have been observed following treatment with Korlym. In study subjects that experienced declines in HDL-C, levels returned to baseline following discontinuation of drug. The clinical significance of the treatment-related reduction in HDL-C levels in patients with Cushing's syndrome is not known.
In a study of patients with Cushing's syndrome, hypokalemia was observed in 44% of subjects during treatment with Korlym. In these cases, hypokalemia responded to treatment with potassium supplementation and/or mineralocorticoid antagonist therapy (e.g., spironolactone or eplerenone). Hypokalemia should be corrected prior to initiating Korlym. [See WARNINGS AND PRECAUTIONS]
Elevations of thyroid-stimulating hormone (TSH) were seen in subjects treated with Korlym. Of the 42 subjects with detectable TSH at baseline, eight (19%) had increases in TSH above the normal range, while remaining asymptomatic. The TSH levels returned to normal in most patients without intervention when Korlym was discontinued at the end of the study.
Vaginal Bleeding and Endometrial Changes
In Study 400, the thickness of the endometrium increased from a mean of 6.14 mm at baseline (n=23) to 15.7 mm at end-of-trial (n=18) in premenopausal women; in postmenopausal women the increase was from 2.75 mm (n=6) to 7.35 mm (n=8). Endometrial thickness above the upper limit of normal was reported in 10/26 females who had baseline and end-of-trial transvaginal ultrasound (38%). The endometrial thickness returned to the normal range in 3 out of 10 patients 6 weeks after treatment cessation at the end of the study. Vaginal bleeding occurred in 5 out of 35 females (14%). Two of five subjects with vaginal bleeding had normal endometrial thickness. Endometrial biopsies were performed in six patients; five of these patients had endometrial thickening. No endometrial carcinoma was detected in the sampled cases.
Additional Data from Clinical Trials
The following are adverse events that were reported in Study 400 at frequencies of ≥ 5% to 10%, and may be related to Korlym's mechanism of action:
Gastrointestinal disorders: gastroesophageal reflux, abdominal pain
Investigations: blood triglycerides increased
Metabolism and nutrition disorders: hypoglycemia
Musculoskeletal and connective tissue disorders: muscular weakness, flank pain, musculoskeletal chest pain
Psychiatric disorders: insomnia
Adrenal insufficiency was reported in two subjects (4%) in Study 400. The most typical symptoms of adrenal insufficiency were nausea and decreased appetite. No hypotension or hypoglycemia was reported during the events. Adrenal insufficiency resolved in both cases with Korlym interruption and /or dexamethasone administration.
Generalized, maculo-papular rash was reported in 2 subjects (4%) in Study 400. Two additional subjects developed pruritus (4%). None resulted in discontinuation of Korlym, and all the events resolved by the end of the study.
Read the entire FDA prescribing information for Korlym (Mifepristone) »
Additional Korlym Information
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
Find out what women really need.