Reviewed on 10/12/2022

What Is Metyrapone and How Does It Work?

Metyrapone is a prescription medication used in the diagnosis of adrenal insufficiency. 

  • Metyrapone is available under various brand names: Metopirone

What Are Side Effects Associated with Using Metyrapone?

Common side effects of Metyrapone include:

  • nausea,
  • upset stomach,
  • headache,
  • dizziness, and
  • drowsiness

Serious side effects of Metyrapone include:

  • hives,
  • difficulty breathing,
  • swelling of the face, lips, tongue, or throat,
  • rash,
  • itching, and
  • severe dizziness

Rare side effects of Metyrapone include:

  • none

Seek medical care or call 911 at once if you have the following serious side effects:

  • Severe headache, confusion, slurred speech, arm or leg weakness, trouble walking, loss of coordination, feeling unsteady, very stiff muscles, high fever, profuse sweating, or tremors;
  • Serious eye symptoms such as sudden vision loss, blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights;
  • Serious heart symptoms include fast, irregular, or pounding heartbeats; fluttering in the chest; shortness of breath; sudden dizziness, lightheadedness, or passing out.

This is not a complete list of side effects and other serious side effects or health problems that may occur because of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.

What Are Dosages of Metyrapone?

Adult and pediatric dosage


  • 250 mg

Adrenocorticotropic hormone (ACTH) Diagnostic Test

Adult and pediatric dosage

  • 15 mg/kg or 300 mg/m² orally every 4 hours for 6 doses; manufacturer recommends minimum single dose of 250 mg

Dosage Considerations – Should be Given as Follows: 

  • See “Dosages”

What Other Drugs Interact with Metyrapone?

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this product, tell your doctor or pharmacist about all your products. Keep a list of all your medications with you and share this information with your doctor and pharmacist. Check with your healthcare professional or doctor for additional medical advice, or if you have health questions or concerns.

What Are Warnings and Precautions for Metyrapone?


  • Adrenocortical insufficiency
  • Hypersensitivity

Effects of drug abuse

  • None

Short-Term Effects

  • See “What Are Side Effects Associated with Using Metyrapone?”

Long-Term Effects

  • See “What Are Side Effects Associated with Using Metyrapone?”


  • 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

  • Use with caution if benefits outweigh risks during pregnancy
  • Lactation
    • Unknown, use with caution

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