Leucovorin is a form of folic acid. Folic acid helps your body produce and maintain new cells, and also helps prevent changes to DNA that may lead to cancer. Folic acid is present in many foods such as dried beans, peas, oranges, spinach, and others.

Leucovorin is used to reduce the side effects of large doses or accidental overdose of medications that can reduce the effects of folic acid in the body. This includes methotrexate (Rheumatrex), pyrimethamine (Daraprim), trimethoprim (Trimpex, Proloprim), and others.

Leucovorin may also be used for purposes not listed in this medication guide.

You should not take leucovorin if you have pernicious anemia or other types of anemia caused by a lack of vitamin B12.

Leucovorin comes as a tablet to take by mouth. It is usually taken every 6 hours until laboratory tests show it is no longer needed. Sometimes leucovorin is taken on a different schedule, depending on the reason it is needed. Take leucovorin at around the same time(s) every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take leucovorin exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Follow all directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended.

When treating an accidental overdose, leucovorin should be started as soon as possible for the best effect.

Leucovorin is usually given with other medications to help your kidneys remove methotrexate from your body. You may also be treated with IV fluids to keep you from getting dehydrated.

You will need frequent medical tests to help your doctor determine how long to treat you with leucovorin.

Store at room temperature away from moisture, heat, and light.

You should not take leucovorin if you have pernicious anemia or other types of anemia caused by a lack of vitamin B12.

If possible before you receive leucovorin, tell your doctor if you have:

• liver disease;

• kidney disease;

• breathing problems; or

• if you are dehydrated.

Also tell your doctor about all other medications you currently use. There are many other drugs that can interact with methotrexate and slow down your body's ability to process and eliminate the drug. This can affect how quickly methotrexate is able to leave your body, even with the help of leucovorin.

It is not known whether leucovorin will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

It is not known whether leucovorin passes into breast milk or if it could harm a nursing baby. Tell your doctor if you are breast-feeding a baby.

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

An overdose of leucovorin is not likely to cause life-threatening symptoms. However, leucovorin overdose can make other medications less effective.

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org

Unless your doctor tells you otherwise, continue your normal diet.

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Tell your doctor about all your current medicines and any you start or stop using, especially:

• fluorouracil;

• sulfamethoxazole and trimethoprim (Bactrim, Cotrim, SMZ-TMP or SMX-TMP); or

• seizure medicine--phenobarbital, phenytoin, primidone.

This list is not complete. Other drugs may interact with leucovorin, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.

Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your body's response to leucovorin.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.