Folinic acid (leucovorin or calcium folinate)

Folinic acid is also known as calcium folinate or leucovorin. It is used to make chemotherapy work better, or to reduce its side effects.

What is folinic acid?

Folinic acid (also called calcium folinate or leucovorin) is not a chemotherapy drug. But it may be given with the chemotherapy drugs:

Folinic acid is often given with 5FU to treat cancers of the colon, rectum and other parts of the digestive system. It makes 5FU work better. It may also be given with tegafur-uracil which is a similar drug to 5FU.

Methotrexate is used to treat different types of cancer. Folinic acid is mainly used with higher doses of methotrexate to help reduce the side effects. This is sometimes called folinic acid rescue or leucovorin rescue.

It is best to read this information with our general information about chemotherapy and the type of cancer you have.

Your doctor will talk to you about this treatment and its possible side effects before you agree (consent) to have treatment.

More information about this treatment

This information is correct at time of publishing. But sometimes the types of cancer this treatment is used for, or treatment side effects, may change between revision dates.

You can talk to your cancer team if you want more detailed information about this treatment. Or visit the electronic Medicines Compendium (eMC) website, which has patient information leaflets (PIL) for individual drugs.

How folinic acid is given

You will be given folinic acid in the chemotherapy day unit or during a stay in hospital. A chemotherapy nurse will give it to you at the same time as your chemotherapy. 

During treatment you will usually see a cancer doctor, a chemotherapy nurse, or a specialist nurse, and a specialist pharmacist. This is who we mean when we mention doctor, nurse or pharmacist in this information.

Before or on the day of treatment, a nurse or person trained to take blood (phlebotomist) will take a blood sample from you. This is to check that your blood cells are at a safe level to have the chemotherapy part of the treatment.

You will see a doctor or nurse before you have treatment. They will ask you how you have been feeling. If your blood results are okay, the pharmacist will prepare your drugs. Your nurse will tell you when your treatment is likely to be ready.

You may have folinic acid as a drip (infusion) or injection through: 

  • a cannula – a short, thin tube the nurse puts into a vein in your arm or hand
  • a central line – a fine tube that goes under the skin of your chest and into a vein close by
  • a PICC line – a fine tube that is put into a vein in your arm and goes up into a vein in your chest
  • an implantable port (portacath) – a disc that is put under the skin on your chest or arm and goes into a vein in your chest.

You may also have folinic acid as a tablet. Before you leave hospital, the nurse or pharmacist will give you the tablets to take at home. It is important to take your tablets exactly as explained. This is to make sure they work as well as possible for you.

Contact the hospital

Your doctor, nurse or pharmacist will give you 24-hour contact numbers for the hospital. If you feel unwell or need advice, you can call at any time of the day or night. Save these numbers in your phone or keep them somewhere safe.

Possible side effects

Side effects from folinic acid are rare. Sometimes you may have a high temperature (fever) after the drug has been given. Your doctor may prescribe some tablets to help with this.

Any side effects you have are likely to be related to the chemotherapy drugs. But if you notice any side effects that you think may be related to the folinic acid, talk to your doctor, nurse or pharmacist.

If you feel ill or have any severe side effects during cancer treatment, it is important to tell your doctor or nurse straight away.

Other information

Blood clot risk

Cancer and some cancer treatments can increase the risk of a blood clot. Contact the hospital straight away on the 24-hour number if you have any of these symptoms during or after treatment:

  • throbbing pain or swelling in a leg or arm
  • reddening of the skin in the area – if you have black or brown skin, this can be harder to notice, but the skin might become darker
  • suddenly feeling breathless or coughing.

Always call 999 if you have:

  • chest pain
  • difficulty breathing.

A blood clot is serious, but it can be treated with drugs called anticoagulants. These thin the blood. Your doctor, nurse or pharmacist can give you more information about preventing and treating blood clots.

Other medicines

Some medicines can affect how this treatment works or be harmful while you are having it. Always tell your cancer doctor, nurse or pharmacist about any drugs you are taking or planning to take, such as: 

Lactose

Folinic acid tablets contain a small amount of lactose. If you have a lactose intolerance, talk to your doctor before taking folinic acid.

Breastfeeding

You are advised not to breastfeed while having this treatment, or for some time after treatment ends. This is because the drugs could be passed to the baby through breast milk. 

Your doctor, nurse or pharmacist can give you more information.

Medical and dental treatment

If you need medical treatment for any reason other than cancer, always tell the healthcare professional that you are having cancer treatment. Give them the contact details for your cancer doctor or cancer team so they can ask for advice.

If you have appointments with a dentist, always tell them you are having cancer treatment. Talk to your cancer team before you have any dental treatment.

About our information

  • Reviewers

    This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert health professionals and people living with cancer.

    Our cancer information has been awarded the PIF TICK. Created by the Patient Information Forum, this quality mark shows we meet PIF’s 10 criteria for trustworthy health information.

The language we use

We want everyone affected by cancer to feel our information is written for them.

We want our information to be as clear as possible. To do this, we try to:

  • use plain English
  • explain medical words
  • use short sentences
  • use illustrations to explain text
  • structure the information clearly
  • make sure important points are clear.

We use gender-inclusive language and talk to our readers as ‘you’ so that everyone feels included. Where clinically necessary we use the terms ‘men’ and ‘women’ or ‘male’ and ‘female’. For example, we do so when talking about parts of the body or mentioning statistics or research about who is affected.

You can read more about how we produce our information here.

Date reviewed

Reviewed: 01 March 2022
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Next review: 01 September 2024
Trusted Information Creator - Patient Information Forum
Trusted Information Creator - Patient Information Forum

Our cancer information meets the PIF TICK quality mark.

This means it is easy to use, up-to-date and based on the latest evidence. Learn more about how we produce our information.