Overview
11 DESCRIPTION KORLYM (mifepristone) is a cortisol receptor blocker for oral administration. The chemical name of mifepristone is 11β-(4-dimethylaminophenyl)-17β-hydroxy-17α-(1-propynyl)-estra-4, 9-dien-3-one. The chemical formula is C 29 H 35 NO 2 ; the molecular weight is 429.60, and the structural formula is: Mifepristone demonstrates a pH-related solubility profile.
Mechanism of Action
12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action Mifepristone is a selective antagonist of the progesterone receptor at low doses and blocks the glucocorticoid receptor (GR-II) at higher doses. Mifepristone has high affinity for the GR-II receptor but little affinity for the GR-I (MR, mineralocorticoid) receptor. In addition, mifepristone appears to have little or no affinity for estrogen, muscarinic, histaminic, or monoamine receptors. 12.2 Pharmacodynamics Because mifepristone acts at the receptor level to block the effects of cortisol, its antagonistic actions affect the hypothalamic-pituitary-adrenal (HPA) axis in such a way as to further increase circulating cortisol levels while, at the same time, blocking their effects.
Indications
- 1 INDICATIONS AND USAGE KORLYM (mifepristone) is a cortisol receptor blocker indicated to control hyperglycemia secondary to hypercortisolism in adult patients with endogenous Cushing's syndrome who have type 2 diabetes mellitus or glucose intolerance and have failed surgery or are not candidates for surgery. LIMITATIONS OF USE: KORLYM should not be used in the treatment of patients with type 2 diabetes unless it is secondary to Cushing's syndrome.
Common Doses
- 300 mg
- 1200 mg
- 20 mg
- 600 mg
Dosage
2 DOSAGE AND ADMINISTRATION Obtain a negative pregnancy test in females of reproductive potential prior to initiating treatment with KORLYM or if treatment is interrupted for more than 14 days. ( 2.1 ) Administer once daily orally with a meal ( 2.2 ). The recommended starting dose is 300 mg once daily ( 2.2 ). Based on clinical response and tolerability, the dose may be increased in 300 mg increments to a maximum of 1200 mg once daily. Do not exceed 20 mg/kg per day ( 2.2 ). Renal impairment: do not exceed 600 mg once daily ( 2.3 ).
Black Box Warning
WARNING: TERMINATION OF PREGNANCY Mifepristone is a potent antagonist of progesterone and cortisol via the progesterone and glucocorticoid (GR-II) receptors, respectively. The antiprogestational effects will result in the termination of pregnancy. Pregnancy must therefore be excluded before the initiation of treatment with KORLYM and prevented during treatment and for one month after stopping treatment by the use of a non-hormonal medically acceptable method of contraception unless the patient has had a surgical sterilization, in which case no additional contraception is needed.
Contraindications
- 4 CONTRAINDICATIONS KORLYM is contraindicated in: Pregnancy [See Dosage and Administration ( 2.1 ), Use in Specific Populations ( 8.1 , 8.3 )] Patients taking drugs metabolized by CYP3A such as simvastatin, lovastatin, and CYP3A substrates with narrow therapeutic ranges, such as cyclosporine, dihydroergotamine, ergotamine, fentanyl, pimozide, quinidine, sirolimus, and tacrolimus, due to an increased risk of adverse events. [See Drug Interactions ( 7.1 ) and Clinical Pharmacology ( 12.3 )] Patients receiving systemic corticosteroids for lifesaving purposes (e.g.
Side Effects
- 6 ADVERSE REACTIONS Most common adverse reactions in Cushing's syndrome (≥ 20%): nausea, fatigue, headache, decreased blood potassium, arthralgia, vomiting, peripheral edema, hypertension, dizziness, decreased appetite, endometrial hypertrophy ( 6 ). To report suspected adverse reactions, contact Corcept Therapeutics at 1-855-844-3270 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 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...
Interactions
- 7 DRUG INTERACTIONS Based on the long terminal half-life of mifepristone after reaching steady state, at least 2 weeks should elapse after cessation of KORLYM before initiating or increasing the dose of any interacting concomitant medication. Drugs metabolized by CYP3A: Administer drugs that are metabolized by CYP3A at the lowest dose when used with KORLYM ( 7.1 ). CYP3A inhibitors: Caution should be used when KORLYM is used with strong CYP3A inhibitors. Limit mifepristone dose to 900 mg per day when used with strong CYP3A inhibitors ( 7.2 ).