Skip to Content
Looking to save on your medications?  Find out how 

Demser

Generic name: metyrosine

What is Demser used for?

  • Demser is used to treat pheochromocytoma.

Before taking Demser, tell your doctor:

  • If you are allergic to Demser; any part of this medicine; or any other drugs, foods, or substances. Tell your doctor about the allergy and what signs you had.

This medicine may interact with other drugs or health problems.

Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take Demser with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.

What are some things I need to know or do while I take Demser?

  • Tell all of your health care providers that you take Demser. This includes your doctors, nurses, pharmacists, and dentists.
  • Avoid driving and doing other tasks or actions that call for you to be alert until you see how Demser affects you.
  • Check your blood pressure as you have been told.
  • Have your urine checked as you have been told by your doctor.
  • Have your blood work checked if you are on Demser for a long time. Talk with your doctor.
  • This medicine may affect certain lab tests. Tell all of your health care providers and lab workers that you take Demser.
  • In most people who get sleepy when taking Demser, changes in sleep pattern happen after stopping Demser. People who do not get sleepy when taking Demser may also have changes in sleep pattern after stopping Demser. Changes like not being able to sleep may last for 2 to 3 days. Talk with your doctor.
  • Talk with your doctor before you drink alcohol or use other drugs and natural products that slow your actions.
  • Tell your doctor if you are pregnant, plan on getting pregnant, or are breast-feeding. You will need to talk about the benefits and risks to you and the baby.

How is Demser best taken?

Use Demser as ordered by your doctor. Read all information given to you. Follow all instructions closely.

  • Keep taking Demser as you have been told by your doctor or other health care provider, even if you feel well.
  • Drink lots of noncaffeine liquids unless told to drink less liquid by your doctor.

What do I do if I miss a dose?

  • Take a missed dose as soon as you think about it.
  • If it is close to the time for your next dose, skip the missed dose and go back to your normal time.
  • Do not take 2 doses at the same time or extra doses.

What are the side effects of Demser that I need to call my doctor about immediately?

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

  • Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
  • Feeling confused.
  • Trouble controlling body movements, twitching, change in balance, trouble swallowing or speaking.
  • Drooling.
  • Trouble passing urine.
  • Pain when passing urine.
  • Back pain, belly pain, or blood in the urine. May be signs of a kidney stone.
  • Anxiety.
  • Depression or other mood changes.
  • Hallucinations (seeing or hearing things that are not there).

What are some other side effects of Demser?

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

  • Diarrhea.
  • Feeling sleepy.

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at https://www.fda.gov/medwatch.

If overdose is suspected:

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

Demser Images

How do I store and/or throw out Demser?

  • Store at room temperature in a dry place. Do not store in a bathroom.
  • Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
  • Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.

Consumer information use and disclaimer

  • If your symptoms or health problems do not get better or if they become worse, call your doctor.
  • Do not share your drugs with others and do not take anyone else's drugs.
  • Some drugs may have another patient information leaflet. Check with your pharmacist. If you have any questions about Demser, please talk with your doctor, nurse, pharmacist, or other health care provider.
  • If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

This information should not be used to decide whether or not to take Demser or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this medicine. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to Demser. This information is not specific medical advice and does not replace information you receive from the healthcare provider. You must talk with the healthcare provider for complete information about the risks and benefits of using this medicine.

Source: Wolters Kluwer Health. Last updated April 5, 2023.