What is Methotrexate?
Methotrexate was first initiated in the 1950’s, developed by the Indian biochemist Yellapragada Subbarao. He initially developed methotrexate as a treatment for cancer. During the 50’s, methotrexate began to replace the more toxic antifolate, aminopterin. Methotrexate is an antimetabolite drug, which means that it can stop the cells’ metabolism. (Cell metabolism consists of creating/destroying important components of their structure, as well as producing energy for the cell.)
How Does Methotrexate Work?
Currently, Methotrexate can be used to treat certain forms of cancer (including leukemia, breast cancer, non-Hodgkin’s lymphoma, stomach cancer, choriocarcinoma, and bladder cancer). This medication has also been effective in treating psoriatic arthritis and psoriasis. In particular, methotrexate has gained widespread use in treating rheumatoid arthritis. However, the exact mechanism of action when used on RA is still unknown. Researchers have theorized that its effectiveness may be due to an ability to alter a patient’s immunity.
As mentioned earlier, methotrexate is an antimetabolite drug. When used as a treatment in cancer patients, the methotrexate will block the enzyme process in cancer cells. By prohibiting this enzyme process, the cancer cells are no longer able to grow.
In rheumatoid arthritis patients, the methotrexate can help reduce the chronic inflammation which is caused by this autoimmune disease. If effective, this drug can help to suppress an RA patient’s immune system, which can help bring their RA symptoms back under control. With psoriasis patients, it will attack the rapidly-dividing cells which cause the rough patchy scales on the skin. When methotrexate is used in either of these two diseases, it is referred to as a disease modifying antirheumatic drug (DMARD).
As mentioned above, methotrexate is a prescribed drug, and it should only be taken by those people who have received a prescription from their doctor. Doctors can prescribe this drug for other conditions besides the ones that are listed above. However, under no circumstances should a person give this drug to anyone else, even if they have the same symptoms as said person.
How Should You Use Methotrexate?
For adults with rheumatoid arthritis, the suggested methotrexate dose is usually 7.5MG. This can be taken orally as one dose every week, or split it up and taken in 2.5MG increments every 12 hours, for 3 doses once a week. Doctors may adjust the RA patient’s dosing according to their individual response to the medication. However, this is done gradually, and only rare cases will need to exceed 20MG weekly. Patients who have been prescribed methotrexate should expect to see benefits within 3 to 6 weeks after starting their treatment.
In cancer patients, the methotrexate dose can vary depending on the type of cancer and the weight/size of the individual. Cancer patients can be prescribed either the injectable or tablet form of methotrexate. If a doctor prescribes it in the injectable form, then the appropriate dose can be taken in either one injection per week or split up to be taken in smaller portions during the week. They can also be taken in cycles (i.e., there will be some weeks where no injections are given) or on a regular schedule, but this all depends upon the type of cancer being treated.
A doctor will most likely prescribe a starting dose of 10MG to 25MG per week for psoriasis patients. The methotrexate will be taken in one dose (can be tablet or injection) every week, although some psoriasis patients can choose to take a 2.5MG tablet every 12 hours for 3 doses once a week. Similar to rheumatoid arthritis patients, the doses may need to be gradually adjusted for psoriasis patients depending on their reaction to the medication (only extreme cases will need to exceed 30MG weekly).
Methotrexate can be prescribed for children, and has been used to treat cancer in children. It can also be used to treat other conditions in children as well, but close supervision by a doctor is required.
Methotrexate has had reported side effects in patients who have been prescribed this medication. This drug can sometimes make patients feel nauseous. Patients should consult their doctor if they start to feel ill after taking methotrexate, but it does not automatically mean they need to stop treatment. There may be other factors at play, which a doctor should be able to discuss with them.
Reported Side Effects of Methotrexate
This is a list of possible side effects which have been reported in at least 1% of the people who have used methotrexate. It is important to note that if many of these are manageable, and some may just go away over time on their own. A patient who experiences any side effects from methotrexate should not hesitate to contact his or her doctor, as a change in dosage or discontinuation of this medication may be needed.
Possible side effects of methotrexate include:
• Loss of appetite
• Blurred vision
• Chest pain
• Ringing in the ears
• Skin rash
• Sore eyes
• Dark urine
• Painful or difficult urination
• Pain in lower back or sides
• Yellow eyes or skin
Again, it is very important that a patient who experiences any side effects contact their doctor immediately. These side effects are rare, but they should not be ignored. Some can cause very serious issues if immediate medical attention is not sought. You may also want to look into some of the new RA treatments being developed.
If any of the following should occur, patients should stop taking methotrexate immediately:
• Severe skin reactions
• Symptoms of severe allergic reaction
• Seizures or convulsions
Drug Identification Number (DIN): 02170698
Tablets: 2.5, 5, 7.5, 10, and 15MG
Injectable: 25mg/ml; powder for injection 1 g
Nonmedicinal Ingredients: corn starch, lactose, and magnesium stearate. Dye-free.
Drug Class: Antimetabolite drug
Dosing: Can be taken with or without food.
Storage: Store at room temperature, and avoid light.