Dosing & Uses
Dosage Forms & Strengths
capsule
- 250mg
ACTH Diagnostic Test
Single dose test
- 30 mg/kg PO at midnight; not to exceed 3 g/dose
Multiple dose test
- 750 mg PO q4hr x6 doses
Administration
4 days prior to administration, collect and test a control 24-hour urine specimen for 17-hydroxycorticosteroids (17-OHCS) or 17-Ketogenic steroids (17-KGS) (alternatively, urinary tetrahydrodeoxycortisol, THS)
On the following day, perform corticotropin test to rule out adrenocortical insufficiency
May take with milk or food to reduce GI irritation
Cushing's Syndrome Treatment (Off-label)
250 mg PO q4hr; not to exceed 6 g/day
Dosage Forms & Strengths
capsule
- 250mg
ACTH Diagnostic Test
15 mg/kg or 300 mg/m² PO q4hr x6 doses; manufacturer recommends minimum single dose of 250 mg
Administration
4 days prior to administration, collect and test a control 24-hour urine specimen for 17-hydroxycorticosteroids (17-OHCS) or 17-Ketogenic steroids (17-KGS) (alternatively, urinary tetrahydrodeoxycortisol, THS)
On the following day, perform corticotropin test to rule out adrenocortical insufficiency
May take with milk or food to reduce GI irritation
Interactions
Interaction Checker
No Results

Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor

Contraindicated (1)
- cyproheptadine
cyproheptadine decreases effects of metyrapone by pharmacodynamic antagonism. Contraindicated.
Serious - Use Alternative (3)
- eluxadoline
metyrapone increases levels of eluxadoline by decreasing metabolism. Avoid or Use Alternate Drug. Decrease eluxadoline dose to 75 mg PO BID if coadministered with OATP1B1 inhibitors. .
- ethinylestradiol
ethinylestradiol decreases effects of metyrapone by unspecified interaction mechanism. Avoid or Use Alternate Drug. A subtherapeutic response to metyrapone can be seen in patients on estrogens, including oral contraceptives, that contain estrogen therapy. It may be advisable to discontinue estrogens prior to and during metyrapone administration.
- pacritinib
metyrapone will decrease the level or effect of pacritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
Monitor Closely (12)
- atorvastatin
metyrapone increases toxicity of atorvastatin by Other (see comment). Use Caution/Monitor. Comment: OATP1B1 inhibitors may increase risk of myopathy.
- ethotoin
ethotoin decreases levels of metyrapone by increasing metabolism. Use Caution/Monitor.
- fosphenytoin
fosphenytoin decreases levels of metyrapone by increasing metabolism. Use Caution/Monitor.
- glecaprevir/pibrentasvir
metyrapone will increase the level or effect of glecaprevir/pibrentasvir by decreasing metabolism. Use Caution/Monitor. Caution when coadministering glecaprevir/pibrentasvir with OATP1B1/OATP1B3 inhibitors
- letermovir
metyrapone increases levels of letermovir by decreasing metabolism. Use Caution/Monitor. Coadminstration of letermovir, an OATP1B1/3 substrate, with OATP1B1/3 inhibitors may increase letermovir plasma concentrations.
- phenytoin
phenytoin decreases levels of metyrapone by increasing metabolism. Use Caution/Monitor.
- pitavastatin
metyrapone increases toxicity of pitavastatin by Other (see comment). Use Caution/Monitor. Comment: OATP1B1 inhibitors may increase risk of myopathy.
- pravastatin
metyrapone increases toxicity of pravastatin by Other (see comment). Use Caution/Monitor. Comment: OATP1B1 inhibitors may increase risk of myopathy.
- rosuvastatin
metyrapone increases toxicity of rosuvastatin by Other (see comment). Use Caution/Monitor.
- sacubitril/valsartan
metyrapone will increase the level or effect of sacubitril/valsartan by Other (see comment). Use Caution/Monitor. The results from an in vitro study with human liver tissue indicate that valsartan is a substrate of the hepatic uptake transporter OATP1B1; coadministration with OATP1B1 inhibitors may increase valsartan systemic exposure
- simvastatin
metyrapone increases toxicity of simvastatin by Other (see comment). Use Caution/Monitor. Comment: OATP1B1 inhibitors may increase risk of myopathy.
- valsartan
metyrapone will increase the level or effect of valsartan by Other (see comment). Use Caution/Monitor. The results from an in vitro study with human liver tissue indicate that valsartan is a substrate of the hepatic uptake transporter OATP1B1; coadministration with OATP1B1 inhibitors may increase valsartan systemic exposure
Minor (29)
- amitriptyline
amitriptyline decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.
- bazedoxifene/conjugated estrogens
bazedoxifene/conjugated estrogens decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.
- budesonide
budesonide decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.
- chlordiazepoxide
chlordiazepoxide decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.
- chlorpromazine
chlorpromazine decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.
- conjugated estrogens
conjugated estrogens decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.
- conjugated estrogens, vaginal
conjugated estrogens, vaginal decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.
- cortisone
cortisone decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.
- deflazacort
deflazacort decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.
- dexamethasone
dexamethasone decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.
- estradiol
estradiol decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.
- estrogens conjugated synthetic
estrogens conjugated synthetic decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.
- estrogens esterified
estrogens esterified decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown. A subtherapeutic response to metyrapone can be seen in patients on estrogen therapy. It is generally advisable to discontinue estrogens prior to and during metyrapone administration.
- estropipate
estropipate decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.
- fludrocortisone
fludrocortisone decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.
- fluphenazine
fluphenazine decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.
- hydrocortisone
hydrocortisone decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.
- mestranol
mestranol decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.
- methylprednisolone
methylprednisolone decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.
- perphenazine
perphenazine decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.
- phenobarbital
phenobarbital decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.
- prednisolone
prednisolone decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.
- prednisone
prednisone decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.
- prochlorperazine
prochlorperazine decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.
- promazine
promazine decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.
- promethazine
promethazine decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.
- thioridazine
thioridazine decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.
- triamcinolone acetonide injectable suspension
triamcinolone acetonide injectable suspension decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.
- trifluoperazine
trifluoperazine decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.
Adverse Effects
Frequency Not Defined
Abdominal discomfort
Bone marrow depression (rare)
Decr leukocyte count (rare)
Dizziness
Fall in arterial blood pressure
Headache
Nausea
Pulse rate incr
Sedation
Vertigo
Warnings
Contraindications
Adrenocortical insufficiency
Hypersensitivity
Cautions
May cause CNS depression, which may impair physical or mental abilities
Discontinue all corticosteroid therapy prior to, and during metyrapone test
Discontinue phenytoin at least 2 wk before metyrapone test
Pregnancy/lactation
Pregnancy & Lactation
Pregnancy Category: C
Lactation: unknown, use with caution
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.Pharmacology
Mechanism of Action
Inhibits formation of cortisol, corticosterone, and aldosterone
Pharmacokinetics
Half-life elimination: 1.9 hr (metyrapone)
Onset: Within 24 hr of administration (peak steroid excretion)
Peak Plasma: 1.2 mcg/mL
Metabolism: Liver and kidney; metabolized to an active reduced metabolite
Enzyme Inhibited: 11-beta-hydroxylase
Excretion: ~40% in urine (37% as glucuronide conjugates, 3% as the reduced metabolite and 0.5% unchanged)
Images
BRAND | FORM. | UNIT PRICE | PILL IMAGE |
---|---|---|---|
Metopirone oral - | 250 mg capsule | ![]() |
Copyright © 2010 First DataBank, Inc.
Patient Handout
metyrapone oral
METYRAPONE - ORAL
(me-TIR-a-pone)
COMMON BRAND NAME(S): Metopirone
USES: Metyrapone is used to test if your pituitary gland is sending the proper signals to your adrenal glands. Normally the pituitary gland in your brain sends signals to your adrenal glands to make a natural substance called cortisol. Cortisol is important for keeping your body functioning well and for good health.
HOW TO USE: Take this medication by mouth with milk or a snack as directed by your doctor. The dosage is based on your weight.If you are directed to use the single-dose test, take your dose of metyrapone at midnight. Early the next morning, your doctor will take a blood sample from you.If you are directed to use the multiple-dose test, take this medication exactly at the times recommended by your doctor. For one day, several days before taking this medication, you will need to collect all your urine for a 24-hour period for testing, and then again on the day after you take this medication.It is important to take this medication as directed to assure proper test results.
SIDE EFFECTS: Nausea, upset stomach, headache, dizziness, or drowsiness may occur. If any of these effects last or get worse, tell your doctor promptly.Remember that your doctor has prescribed this medication because the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
PRECAUTIONS: Before taking metyrapone, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.Before using this medication, tell your doctor or pharmacist your medical history, especially of: decreased adrenal gland function (primary adrenal insufficiency), thyroid problems.This drug may make you dizzy or drowsy. Alcohol or marijuana (cannabis) can make you more dizzy or drowsy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor. A below-normal response to this medication may occur in pregnant women.It is unknown if this medication passes into breast milk. Consult your doctor before breast-feeding.
DRUG INTERACTIONS: Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.Some products that may interact with this drug include: acetaminophen, cyproheptadine, estrogens, hydantoins (such as phenytoin).If you are taking corticosteroids (such as hydrocortisone, prednisone), these medications must be stopped before and during metyrapone testing. Consult your doctor for more details about how to do so safely.
OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: fast/irregular heartbeat, severe dizziness, anxiety, confusion, weakness, vomiting, stomach pain.
NOTES: Do not share this medication with others.Blood or urine tests will be done to test your response to this medication. Consult your doctor for more details.
MISSED DOSE: If you miss a dose, contact your doctor right away for advice and instructions.
STORAGE: Store at room temperature away from moisture, light, and heat. Do not store in the bathroom. Keep all medications away from children and pets.Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.
Information last revised May 2023. Copyright(c) 2023 First Databank, Inc.
IMPORTANT: HOW TO USE THIS INFORMATION: This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.
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