Methotrexate is used to treat severe rheumatoid arthritis (inflammation in joints of fingers, wrist, feet, ankles) and psoriasis (a type of skin disease that allows the skin cells to rapidly build up causing itchy patches of thick, red skin and silvery scales) in individuals who do not respond well to other forms of treatment.
This medicine may be used to treat other conditions as decided by your doctor.
If you or your caregiver had been given the proper training on the preparation and injection techniques of Methotrexate, you or your caregiver may do the administration.
Use this medicine exactly as directed by your doctor or according to the instructions on the label. Do not use more or less than instructed by your doctor.
Methotrexate is to be injected subcutaneously (into the fatty layer under the skin, usually in the thigh, upper arm or abdomen area).
Remember to rotate the injection sites. Do not inject into the same area all the time. New injection sites should be at least 1.5 inches away from the previous injection site. Do not inject near the navel (belly button).
This medicine is usually used once a week. Try to use it on the same scheduled day and time.
This medicine is available as a pre-filled pen, injector or syringe. Make sure you know how to use the specific device you have been given. If you have problems or do not understand the instructions, ask your doctor or pharmacist.
Methotrexate must be used regularly for it to be effective. Continue using this medicine even when you feel better. Do not stop using it unless instructed by the doctor.
Inject the missed dose as soon as you remember.
DO NOT double a dose to make up for a missed dose.
If you often forget to use your medicine, let your doctor and pharmacist know.
Alert your doctor if you have any of the following conditions:
- significant liver disease
- alcoholism (alcohol dependence)
- blood disorder e.g. bone marrow hypoplasia, leucopenia, thrombocytopenia, anaemia
- weakened immune system
- active infection
- stomach ulcer
- severe kidney disease
as Methotrexate may not be suitable for you.
Do not use this medicine if you are pregnant or planning to have a baby soon. If you become pregnant while being treated with this medicine, alert your doctor immediately. Methotrexate may cause harm to your unborn child. You must use proven birth control methods during and for at least 6 months after stopping the treatment.
Do not use this medicine if you are breastfeeding.
Methotrexate may possibly affect male fertility. Men must use adequate contraceptive methods during therapy and for at least 3 months after stopping the treatment. You may wish to discuss birth control methods with your doctor.
Alert your doctor if you have been recently vaccinated.
You must avoid any vaccinations without consulting with your doctor.
Inform your doctor if you have any of the following conditions:
- mild to moderate kidney disease
- fluid build-up around the lung or in the abdominal cavity
- inactive, long-term infection e.g. TB (lung infection known as tuberculosis), hepatitis B or C
- risk factors for liver disease e.g. obesity, diabetes, high cholesterol levels
- lung disease
- low level of vitamin B9 in the body
Be sure to check with your doctor or pharmacist before giving this medicine to a child or an elderly. Children and elderly people may be more sensitive to the side effects.
If you are going to have an operation, including minor surgery and dental work, inform your doctor or dentist that you are using this medicine.
Why is it important to keep my appointments with the doctor?
Keep your appointments with your doctor. Your doctor needs to monitor your condition and check your response to the medication regularly.
- Pregnancy tests must be done before treatment to know if this medicine is suited for you to use.
- Routine tests (e.g. liver/kidney function, complete blood count, chest x-ray) may be done before and during treatment with this medicine.
- Regular monitoring of skin reactions may also be needed during therapy.
Your doctor will advise you about how often you need to have these tests.
Methotrexate may cause dizziness. If affected, do not drive or take part in any activity in which you need to be alert.
Other side effects include any of the following: headache, burning sensation of the skin, rash, hair loss, diarrhoea, nausea, vomiting, indigestion, loss of appetite, joint and muscle pain, loss of libido, absence of menstruation, nose bleed, changes in mood and mouth ulcers.
This medicine may also make your skin more sensitive to sunlight. Apply sunscreen when going outdoors and avoid prolonged exposure to sunlight and UV lamps.
Some side effects may need immediate medical help. Alert your doctor quickly if you experience any of the following:
- rashes with peeling of the skin or blistering of the lips, mouth or eyes accompanied by fever
- fever, chills, night sweats, painless swelling of lymph nodes in the neck, armpits or groin
- yellowing of the skin or eyes, stomach pain, persistent tiredness
- dry cough, difficulty breathing
- swelling in the legs, feet or ankles, reduced amount of urine
- cough with greenish, yellow phlegm; chest pain
- spitting or coughing up blood
This medicine may cause the level of your red blood cells, white blood cells and platelets to drop.
Red blood cells carry oxygen around your body. A fall in the level of red blood cells may make you feel tired and worn out.
White blood cells help your body to fight infections. A fall in the level of your white blood cells may put you at higher risk for infections, such as coughs, colds and flu, which may lead to more serious infections. Avoid crowded places and people who are sick. Inform your doctor if you have a fever, or a cough or flu that does not go away.
Platelets help your blood to clot when there is a cut in the skin. A fall in the level of your platelets may put you at risk of bleeding more than usual. Do not take part in activities where you may fall or get injured, such as contact sports. Inform your doctor if you get any unusual bruising (large bruises or several bruises, especially if the bruises appeared on their own) or bleeding that takes a long time to stop (for example, too much bleeding when you floss or brush your teeth).
Inform your doctor if any of these side effects do not go away or are severe, or if you experience other side effects.
Avoid vaccinations during treatment with Methotrexate.
Inform your doctor and pharmacist if you are taking or using any of these medicines:
- certain antibiotics e.g. chloramphenicol, ciprofloxacin, co-trimoxazole, penicillin, tetracycline
- NSAIDs (medicines for pain and inflammation) e.g. azapropazone, diclofenac, ibuprofen, indometacin, ketoprofen, phenylbutazone, aspirin
- stomach medicines e.g. omeprazole, pantoprazole
- medicines for epilepsy (fits or seizures) e.g. phenytoin, levetiracetam
- medicines for cancer e.g. mercaptopurine
- nitrous oxide (medicine used to block pain and sensation)
- other medicine used for rheumatoid arthritis e.g. leflunomide
- medicines used in organ transplant or certain immune disorders e.g. azathioprine, ciclosporin
- sulfasalazine (medicine used for inflammation of the bowel)
- probenecid (medicine for gout)
- theophylline (asthma medicine)
- other medicine such as retinoids e.g. acitretin (medicine used for psoriasis)
This does not include all medicines that may interact with Methotrexate.
Always inform your doctor and pharmacist if you are taking any other medicines, including herbal tonics such as traditional Chinese medicines, supplements and medicines that you buy without a prescription.
Store in a cool, dry place away from the reach of children.
Protect from light.
Medicines must not be used past the expiry date.
Return any unused or expired medicine to the clinic, hospital, or pharmacy for proper disposal.