What is it?

Methotrexate is a drug that affects the immune system (i.e. an immunosuppressant) and is useful for its steroid sparing effect.

Indications for use

The main use is in treating some types of cancer, but it has been used in chronic inflammatory conditions, such as rheumatoid arthritis, with very beneficial effects. Its use in other conditions, such as Crohn’s disease and ulcerative colitis has also proved beneficial in some cases, particularly those cases not responding to other immunosuppressants.

How is it taken?

It is usually taken in tablet form on a weekly basis. It should be taken with or after food. The tablets should be swallowed whole and not crushed or chewed. Methotrexate can also be given by injection.

The initial starting dose will usually be 7.5 mg weekly. This may be increased by 2.5-5 mg on a monthly basis up to a maximum of 20 mg weekly, depending on how you respond.

It is possible to have a course of 3 treatments in divided doses of 2.5 mg at 12 hourly intervals once weekly. This may be better tolerated if side effects have occurred. A test dose of 5-10 mg may be given one week prior to the start of your treatment to see if any reactions occur.

The lowest effective dose will be given to you but you will not notice a difference straight away. A response can usually be expected by 4-6 weeks, but this may take as long as 12 weeks.

Monitoring

Due to the potentially serious adverse effects on other systems in the body, it is extremely important that you have regular blood tests whilst taking the treatment. The type and frequency of monitoring should be as follows:

• FBC and LTTs every 2 weeks for the first 2 months then monthly thereafter. Inflammatory markers, such as ESR and CRP should be taken to assess response to treatment.
• Urine should be tested regularly.
• Results should be recorded in the monitoring booklet given to you by the doctor or nurse.

NB: Any abnormality on testing should be reported to the doctor or IBD nurse immediately for further advice.

Contraindications

Methotrexate should not be used if you have kidney problems or pre-existing liver disease. It is known to have harmful effects on ova and sperm, therefore it is extremely important that reliable contraceptive methods are used during treatment and for at least 6 months afterwards. You should not breastfeed whilst on treatment.

Are there any side effects?

It is possible that some side effects may occur during treatment. These may include some of the following:

• Nausea
• Loss of appetite
• Mouth ulcers
• Thinning of the hair
• Abdominal discomfort
• Diarrhoea
• Headaches

Less commonly other effects may occur as a result of bone marrow suppression, such as:
• A rash
• Increased bruising
• Increased tendency towards infections
• Anaemia

Rarely, it may cause liver fibrosis/cirrhosis. If alcohol is avoided this has been proven to be rare. Acute inflammation or chronic fibrosis of the lungs may occur. If you get a dry cough in association with breathing difficulties and fever, contact the doctor immediately for further assessment.

Fertility may be affected, but this is reversible on stopping treatment.

Although this list of side effects may seem quite alarming, it does not mean that you will have all, or indeed any of them. The fact that your doctor has decided that this treatment is required to help control your symptoms means that you have a difficult disease that needs strong medication to keep it under control and therefore reduce the risks of complications and possibly avoid the need for surgery.

You should be reassured that you will be closely monitored whilst you are taking the treatment and if any side effects do arise that these will be dealt with accordingly.

Are there any special precautions?

Methotrexate interacts with some drugs so it is important that you tell your doctor about all your other medications so that these are taken into account. The following should be avoided whilst taking methotrexate:

• Alcohol
• Live vaccines
• Anticonvulsants. (e.g phenytoin).
• Non-steroidal anti-inflammatories [NSAIDS] and aspirin-like drugs.
• Penicillins
• Anti-malarial drugs
• Cyclosporin
• Drugs taken for gout

There may be other important drugs to avoid so please speak to your doctor before starting any new treatment.