Your child needs to take the medicine called methotrexate (say: meth-o-TREX-ate). This information sheet explains what methotrexate does, how to give it, and what side effects or problems your child may have when they take this medicine.
What is methotrexate?
Methotrexate is a drug that is used to treat cancer but it can also be used for non-cancerous conditions. It stops the cells from dividing and making new cells. Methotrexate is used to prevent graft versus host disease following bone marrow or stem cell transplant and in the treatment of rheumatoid arthritis and psoriasis.
You may hear methotrexate called MTX. Methotrexate comes in tablet and injection forms.
Before giving methotrexate to your child?
Tell your doctor if your child has ever reacted badly to methotrexate or any other medications, foods, preservatives or colouring agents.
Talk with your child's doctor or pharmacist if your child has any of the following conditions. Precautions may need to be taken with this medicine if your child has:
- infection or recent exposure to infection (for example chickenpox)
- liver or kidney problems
- stomach or intestine problems
- mouth sores
- low blood counts
How should you give your child methotrexate?
Methotrexate is a clear, yellow liquid that is often given by injection (needle) into a vein (intravenous or IV) or into the spinal column (intrathecal or IT). Your child will get methotrexate injections in the hospital clinic or on a nursing unit.
Methotrexate is also available as oral tablets. There are 2 different strengths of tablets (2.5 mg and 10 mg). Be sure to check that the amount of tablets you are giving matches the dose ordered.
Follow these instructions if your child is taking methotrexate tablets:
- Give your child methotrexate exactly as the doctor or pharmacist tells you to, even if your child seems better. Do not change the dose unless your doctor tells you so. Talk to your child's doctor before you stop giving this medicine for any reason.
- Give your child methotrexate at the same time of the day.
- Your child should take all the tablets prescribed for a dose at the same time. For example, if the doctor orders a number of tablets to be taken each day, your child should take all the tablets at the same time of the day.
- Your child should take methotrexate on an empty stomach (at least one hour before meals and at least two hours after a meal).
- If your child is not able to swallow the tablets whole, review the options with your pharmacist.
- Your child's doctor, nurse or pharmacist will review with you what you should do if your child throws up shortly after taking the medication.
What should you do if your child misses a dose of methotrexate?
- Give the missed dose as soon as you remember.
- If it is almost time for the next dose, skip the missed dose. Give the next dose at the regular time.
- Do not give your child two doses to make up for one missed dose.
- If you are not sure what to do, call your child's doctor or contact nurse.
What are the possible side effects of methotrexate?
Your child may have some of these side effects while they take methotrexate. Check with your child's doctor if your child continues to have any of these side effects, and they do not go away, or they bother your child:
- nausea (upset stomach) or vomiting (throwing up)
- hair loss
- mild skin rash
- mouth sores
- mild headache
Call your child's doctor during office hours if your child has any of these side effects:
- unusual weakness or tiredness
- yellow skin or eyes
- lower back or side pain
- swelling of the feet or lower legs
- joint pain
- mouth sores that are interfering with eating or drinking
Most of the following side effects are not common, but they may be a sign of a serious problem. Call your child's doctor right away or take your child to Emergency if your child has any of these side effects:
- fever or chills
- cough or sore throat
- pain or burning when urinating
- severe headache
- skin rash that covers much of the body or is painful or peeling
- blood in the urine, stools, or vomit
- black, tarry stools
- unusual bleeding or bruising
- chest pain or shortness of breath
These side effects from methotraxate taken by intrathecal injection are also serious and require immediate medical attention. Call your doctor or take your child to Emergency if your child has any of these side effects:
- stiff neck
- seizures (convulsions)
- difficulty moving part of the body or one side of the body
- slurred speech
- change in level of consciousness
What safety measures should you take when your child is using methotrexate?
When large doses of methotrexate are given intravenously, extra intravenous fluids and a medicine called leucovorin will be given to reduce side effects from methotrexate.
Your child will receive medicine to prevent upset stomach and throwing up caused by methotrexate when it is given in large doses. Small doses given by mouth do not usually cause upset stomach.
While your child is getting this medicine, your doctor may want your child to drink plenty of fluids so that your child will pass more urine. This will help prevent kidney problems.
Your child may lose their hair. It will grow back once your child is no longer receiving methotrexate. Its color and texture may change. Use a gentle shampoo and a soft brush.
Your child's skin may darken while receiving methotrexate especially on elbows and knees and in skin creases. If this happens, it will slowly fade once your child stops taking methotrexate.
While your child is taking methotrexate, and for several months afterwards, they will be more sensitive to the sun. The skin will burn more easily than normal. To prevent sunburn, your child should wear sunscreen and protective clothing when outdoors.
Methotrexate may cause sores in the mouth. Rinse your child's mouth with a mouthwash made from baking soda to help keep it clean. Your nurse or pharmacist can review this with you. Avoid store bought mouthwash as it may sting and cause dry mouth.
Methotrexate can lower the number of white blood cells in the blood temporarily, which increases your child's chances of getting an infection.
Your child can take the following precautions to prevent infections, especially when the blood count is low:
- Avoid people with infections, such as a cold or the flu.
- Avoid places that are very crowded with large groups of people.
- Be careful when brushing or flossing your child's teeth. Your doctor, nurse or dentist may suggest different ways to clean your child's mouth and teeth.
- You or your child should not touch your child's eyes or inside their nose without washing your hands first.
- Your child's nurse will review with you what to do in case of fever.
Your child should not receive any immunizations (vaccines) without your child's doctor's approval. Your child or anyone else in your household should not get oral polio vaccine while your child is being treated with methotrexate. Tell your child's doctor if anyone in your household has recently received oral polio vaccine. Your child should avoid contact with anyone who has recently received this vaccine. Other live vaccines that your child should not get include measles, mumps and rubella (MMR) and chicken pox vaccine.
Methotrexate can lower the number of platelets in the blood, which increases your child's risk of bleeding. You can take the following precautions:
- Be careful not to cut your child when using a razor, fingernail scissors or toenail clippers.
- Be careful when shaving or waxing.
- Your child should avoid contact sports where bruising or injury could occur.
- Your child should not receive a permanent tattoo or any kind of body piercing.
There is a chance that methotrexate may cause birth defects if it is taken at the time of conception or if it is taken during pregnancy. If your child is sexually active it is best that they use some kind of birth control while receiving methotrexate. Tell the doctor right away if your child may be pregnant.
Methotrexate may interact with other medications, especially when given in high doses. For example, the following medications may affect the levels of methotrexate in the body:
- some antibiotics including penicillins, cephalosporins and cotrimoxazole (also called Septra)
- certain epilepsy medications (e.g. phenytoin)
- aspirin or certain non-steroidal anti-inflammatory medications (e.g. ibuprofen, naproxen)
If your child is due to have methotrexate, your doctor may ask you to stop giving certain medications until after the dose of methotrexate. Check with your doctor or pharmacist when it is safe to re-start the medication.
Multivitamins that contain folic acid can also interfere with the activity of this medication. Be sure to check with your child's doctor or pharmacist before giving your child any other medicines (prescription, non-prescription, herbal or natural products).
Keep all appointments at the clinic or doctor's office so that the doctor can check your child's response to methotrexate. The doctor may need to change the dose that your child is getting from time to time.
Your child's doctor will order tests to check for problems with the liver, kidneys, and blood while your child is getting methotrexate.
Tell the doctor or dentist that your child is taking methotrexate before your child has any kind of operation, even on the teeth, or an emergency treatment.
What other important information should you know about methotrexate?
- Keep a list of all medications your child is on and show the list to the doctor or pharmacist.
- Do not share your child's medicine with others. Do not give anyone else's medicine to your child.
- Make sure you always have enough methotrexate to last through weekends, holidays, and vacations. Call your pharmacy at least 2 days before your child runs out of medicine to order refills. Not all pharmacies will carry methotrexate tablets.
- Keep methotrexate at room temperature in a cool, dry place away from sunlight. Do NOT store it in the bathroom or kitchen.
- Do not keep any medicines that are out of date. Check with your pharmacist about the best way to throw away outdated or leftover medicines.
Keep methotrexate out of your child’s sight and reach and locked up in a safe place. If your child takes too much methotrexate, call your local Poison Information Centre at one of these numbers. These calls are free.
- Call 1-844 POISON-X, or 1-844-764-7669, from anywhere in Canada except Quebec.
- Call 1-800-463-5060 if you live in Quebec.