Méthotrexate

Dr Christophe Hsu – dermatologist. Geneva, Switzerland

Your doctor has just prescribed methotrexate for you.

What is methotrexate used for?

Methotrexate is a medicine used to treat psoriasis. It is also used for many other diseases In Psoriasis, your skin cells grow and mature too rapidly, resulting in elevated, red plaques covered by dry silvery scales. Methotrexate acts by slowing down this excess cell reproduction, so that the skin is restored to a normal appearance.

This medicine has been prescribed for your current medical condition only and should not be given to other people or used for other problems.

How should I take methotrexate?

Methotrexate comes in the form of tablets. Take this medicine only as directed by your doctor.

What should I do if I forget a dose?

If you miss a dose, do not take the missed dose at all and do not double the next one. Resume your regular dosing schedule and check with your doctor.

What other effects will methotrexate cause?

Certain side effects of this medicine are not unusual and may even disappear during treatment. If any of the following effects persist or are severe, consult your doctor:-

• Nausea and vomitingTo reduce these effects take this medicine with some food or take it in divided doses, at 12 hourly intervals in maximum of 3 doses per week.
• Hair lossThis is only temporary. Normal hair growth should return when treatment has ended.
• Loss of appetite
• Acne, rash or itch
• Unusual tiredness or weakness
• Problem in getting to sleep

Consult your doctor as soon as possible if any of these additional effects occur, as they may indicate more serious side effects:

• High fever or chills
• Bloody, black stools or severe stomach ache
• Sores in the mouth or lips
• Unusual bleeding or bruising
• Yellow eyes or skin, with dark coloured urine (jaundice)

What precautions should I take?

• Before taking this medicine, check with your doctor if you are pregnant, intending to conceive or are breastfeeding. Methotrexate is not recommended in pregnancy and breastfeeding mothers. Avoid conception while on methotrexate and for at least a further 12 weeks after stopping methotrexate.
• Inform your doctor of any other medication you are taking as there can be an interaction between both medicines.
• Avoid taking alcohol while on methotrexate. Alcohol can increase the risk of liver problems.
• Do not take aspirin or other anti-inflammatory pain killers eg indomethacin, etc, without first checking with your doctor. These medicines may increase the harmful effects of methotrexate.
• While on methotrexate, your body resistance to infection may be temporarily suppressed. You must inform your doctor before you have any immunisation.
• As this medicine may also reduce your blood clotting ability, it is best to protect yourself from all injuries. Be careful also when cleaning your gums or teeth.
• Keep to your appointments regularly so that your doctor can monitor your response and adjust your treatment accordingly.You will have to have regular blood tests while on methotrexate.

How should I store methotrexate?

• Keep this medicine away from heat and direct sunlight in a cool, dry place, out of reach of children.
• Do not keep this medicine with other medications in the same container. Keep each medicine separately in labelled containers.

Special Notes

1. When you are taking this medicine on a long term basis, your doctor will usually monitor your response by regular blood and liver function tests.

Your Methotrexate Dosage Chart is a useful record of your medication history. Show it to your doctor on every visit to your family physician and skin specialist. When in doubt, consult your doctor or pharmacist.

Contributors:

Dr Christophe HSU – dermatologist. Geneva, Switzerland

National Skin Centre. Singapore