Pyrimethamine

What is pyrimethamine?

Pyrimethamine may be used to treat toxoplasmosis. Pyrimethamine may be given to you for other reasons.

Before taking pyrimethamine, tell your doctor:

• If you are allergic to pyrimethamine; any part of this medicine; or any other drugs, foods, or substances. Tell your doctor about the allergy and what signs you had.
• If you have anemia caused by low folic acid stores.
• If you are breast-feeding or plan to breast-feed.

This is not a list of all drugs or health problems that interact with pyrimethamine.

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 pyrimethamine 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 pyrimethamine?

• Tell all of your health care providers that you take pyrimethamine. This includes your doctors, nurses, pharmacists, and dentists.
• Do not take more than what your doctor told you to take. Taking more than you are told may raise your chance of very bad side effects.
• The chance of cancer is higher after using pyrimethamine. Talk with the doctor.
• Have blood work checked as you have been told by the doctor. Talk with the doctor.
• Folic acid or leucovorin may be needed to avoid side effects. Talk with the doctor.
• Keep away from children. Accidental exposure may cause death. If a child takes pyrimethamine by accident, get medical help right away.
• Use birth control that you can trust to prevent pregnancy while taking pyrimethamine.
• Tell your doctor if you are pregnant or plan on getting pregnant. You will need to talk about the benefits and risks of using pyrimethamine while you are pregnant.
• If you are pregnant or planning on getting pregnant, talk with your doctor. You may need even higher doses of folic acid.

How is pyrimethamine best taken?

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

• Take with or without food. Taking pyrimethamine with food may help with some side effects.
• Keep taking pyrimethamine as you have been told by your doctor or other health care provider, even if you feel well.

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 pyrimethamine 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.
• Fever or chills.
• A heartbeat that does not feel normal.
• Feeling very tired or weak.
• Seizures.
• Blood in the urine.
• Any unexplained bruising or bleeding.
• Sore throat.
• Pale skin.
• Pinpoint red spots on the skin.
• Rash.

What are some other side effects of pyrimethamine?

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:

• Throwing up.
• Not hungry.

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.

How do I store and/or throw out pyrimethamine?

• Store at room temperature.
• Store in a dry place. Do not store in a bathroom.
• Protect from light.
• 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.