Mifepristone

KORLYM

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Pronunciation: mi-FE-pri-stoen (KOR-lim)

Mifepristone ballicule: receptor binding, kinetics and half-life diagram — Mechanism of action: Mifepristone ballicule

What it isProgesterone- and glucocorticoid-receptor antagonist; pregnancy termination and Cushing-syndrome hyperglycemia.

Why this oneThe same receptor pharmacology enables medical abortion with misoprostol and cortisol blockade without lowering cortisol levels.

What limits itAbortion use can cause severe bleeding or infection; Cushing treatment can cause adrenal insufficiency, hypokalemia, and QT prolongation.

Mifepristone molecular structure (skeletal formula) — Molecular structure: Mifepristone

FDA-approved for

pregnancy termination (2000)
Cushing hyperglycemia (2012)

FDA label

Read the full label on DailyMed ↗

BOXED WARNING Serious and sometimes fatal infection or bleeding may follow abortion; infection (e.g., C. sordellii) can present atypically without fever; prolonged heavy bleeding may signal incomplete abortion; available only through the Mifepristone REMS Program

FDA dosing	Population	Start	Target	Max
Medical termination of intrauterine pregnancy ≤70 days gestation	Adult	200 mg PO once (Day 1)	200 mg once + misoprostol 800 mcg buccal 24–48 h later	200 mg single dose

Renal Undefined

Hepatic Undefined

Misoprostol must be taken within 24–48 h of mifepristone (efficacy lower outside window)

Instructions

One 200 mg tablet as a single oral dose on Day 1
Misoprostol 800 mcg buccally 24–48 h after mifepristone (place 2 tablets in each cheek pouch 30 min, then swallow remnants)
Remove any IUD before treatment
Post-treatment follow-up at Day 7–14 to confirm complete termination
Provide Rh immunization prophylaxis as for surgical abortion

Available strengths

tab 200, 300 mg

Contraindications

Confirmed/suspected ectopic pregnancy or undiagnosed adnexal mass
Chronic adrenal failure
Concurrent long-term corticosteroid therapy
Allergy to mifepristone, misoprostol, or other prostaglandins
Hemorrhagic disorders or concurrent anticoagulant therapy
Inherited porphyrias
IUD in place (remove before use)

Cautions

Infection and sepsis (may present atypically without fever)
Prolonged/heavy uterine bleeding — may need surgical intervention
Undiagnosed ectopic pregnancy
Rhesus immunization prevention needed
Restricted distribution via REMS

Adverse reactions

Nausea
Weakness
Fever/chills
Vomiting
Headache
Diarrhea
Dizziness
Uterine bleeding/cramping (expected)

Pregnancy Indicated to terminate pregnancy; failed termination followed by continued pregnancy risks fetal malformation (misoprostol embryopathy/skull deformities in animals)

Lactation Present in human milk at undetectable-to-low levels (relative infant dose ≤0.5%)

Cost

Mifepristone (KORLYM)

Strength		#/mo	generic $/unit	CostPlus
200 mg	tab	per unit		not offered
300 mg	tab	per unit		not offered

NADAC is a voluntary CMS survey of what retail community pharmacies pay for the drugs they stock. Mifepristone is dispensed outside retail pharmacies, so it rarely appears on surveyed invoices.

Generic entry2019

⚠ BOXED WARNING

Serious and sometimes fatal infection and bleeding

Classes and tags

Clinical profile

Therapeutic safety burden3 / 4

Overdose danger1 / 4

Weight-gain liability0 / 4

Sedation liability0 / 4

QT / Torsades2 / 4

Direct muscarinic antagonism0 / 4

Embryofetal risk4 / 4

Legacy pregnancy categoryX

Defining liabilityGenerally tolerated at therapeutic doses; clinically important risks are agent-specific and increase with interactions or organ impairment.

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