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”