Metyrosine

Metyrosine is a prescription medication used for the treatment of chronic pheochromocytoma. 

• Metyrosine is available under the following different brand names: Demser.

Common side effects of Metyrosine include:

• Drowsiness, and
• Involuntary muscle movement

Serious side effects of Metyrosine include:

• Hives, 
• Difficulty breathing, 
• Swelling of the face, lips, tongue, or throat, 
• Drooling, 
• Trouble speaking, 
• Confusion, 
• Hallucinations,
• Tremors or muscle spasms, 
• Painful or difficult urination, 
• Urination that looks cloudy, and 
• Severe or ongoing diarrhea

Rare side effects of Metyrosine 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.

Adult and pediatric dosage

Capsule

• 250 mg

Chronic Pheochromocytoma

Adult dosage

• Initial: 250 mg orally every 6 hours; may increase by 250-500 mg/day, not to exceed 4 g/day
• Maintenance: Typically, 2-3 g/day divided every 6 hours

Pediatric dosage

• Below 12 years: Safety and efficacy not established.
• 12 years and above:
  • Initial: 250 mg orally every 6 hours; may increase by 250-500 mg/day, not to exceed 4 g/day
  • Maintenance: Typically, 2-3 g/day divided every 6 hours

Dosage Considerations – Should be Given as Follows: 

• See “Dosages”

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.

• Metyrosine has severe interactions with no other drugs.
• Metyrosine has serious interactions with the following drugs:
  • lofexidine
  • metoclopramide intranasal
  • olopatadine intranasal
  • ropeginterferon alfa 2b
• Metyrosine has moderate interactions with the following drugs:
  • carbidopa
  • clonidine
  • daridorexant
  • difelikefalin
  • midazolam intranasal
  • stiripentol
  • xipamide
  • Metyrosine has minor interactions with the following drugs:
  • agrimony
  • brimonidine
  • chlorpromazine
  • cornsilk
  • fluphenazine
  • forskolin
  • haloperidol
  • maitake
  • octacosanol
  • perphenazine
  • prochlorperazine
  • promazine
  • promethazine
  • reishi
  • Shepherd’s purse
  • thioridazine
  • tizanidine
  • trifluoperazine

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, health questions, or concerns.

Contraindications

• Hypersensitivity to metyrosine

Effects of drug abuse

• None

Short-Term Effects

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

Long-Term Effects

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

Cautions

• Additive sedative effects with alcohol and other CNS depressants
• Take enough fluid to prevent crystalluria.
• Use caution in hepatic or renal impairment.
• Not recommended for essential HTN

Pregnancy and Lactation

• Use with caution if the benefits outweigh the risks during pregnancy.
• Lactation
  • Not known if excreted into breast milk, use caution