MTX and folic acid play an important role in the treatment of RA.
MTX is the main drug for the treatment of RA
MTX:(methotrexate, methotrexate, rheumatrex, methotrexate)
With a content of 2 mg per capsule, it is the most reliable and most effective anti-rheumatic drug.
MTX is now the world's first-line anti-rheumatic drug.
I prescribe it to most people, except for those with very mild RA, severe liver damage, lung disease, and those who are considering pregnancy.
It has been used as an anti-cancer drug for a long time, but it works well just by administering about 1/100 of the amount used as an anti-cancer drug once or twice a week.
Start with a small dose of 4mg-8mg (2-4 capsules) per week, deciding the day of the week to take, and increase over several months until it works.
(20 mg for men, 16 mg for women)
It seems that the effect often comes out within 1 to 2 months after starting to take it.
About the dose of MTX
In Japan, the maximum weekly dose was 8 mg (= 4 capsules).
Revised in 2011, administration up to 16 mg / week was approved.
In Western countries other than Japan and Asian countries, up to 25 mg (Rheumatrex 10-12 capsules) has been used if necessary.
In recent years, it seems that the number of facilities that administer up to 30 mg-40 mg is increasing.
There were many patients who developed RA due to dose restrictions, although it would be better to use a sufficient amount.
With this revision of the package insert, Japanese rheumatologists will gradually become accustomed to the administration of 12 mg or more, and will be less afraid of side effects.
At our outpatient clinic for RA, it is my responsibility to prescribe the most appropriate amount for each patient for many years.
The appropriate amount is the amount that gives the maximum effect without strong side effects.
The goal of RA control is to some extent the blood number CRP, which indicates the intensity of inflammation.
But symptoms are more important than test numbers.
- Zero joint swelling, occasional mild pain.
- Not only housework, but also sports such as jogging, tennis, golf, travel, and mountain walking can be done like ordinary people.
That is our first treatment goal line.
You can replace it with the jargon "relief." So, if rheumatic pain or swelling persists, increase MTX, even if CRP is low. (Of course, if strong side effects appear, it will be the upper limit of MTX dose.) Instead, the side effects will be strictly checked. rest assured.
About side effects of MTX
Compared to the most commonly used anti-rheumatic drugs such as Shiozol, it has fewer side effects.
However, it should be noted that dangerous side effects such as interstitial pneumonia (whitening of the lungs due to X-ray) and leukopenia rarely occur. If you do not neglect the correct dosage and check and deal with it early, it will not be important.
Check the chest X-ray before starting administration.
In addition, 3 to 4 weeks after the start of administration, a blood test will be performed to check for side effects and check the decrease in CRP.
If it becomes stable, blood sampling will be reduced every 1-2 months.
If you experience symptoms such as coughing, fever, suffocation, or severe general malaise, do not wait for the next day of your visit, but go to the clinic immediately to have a chest X-ray and a blood test.
Other common side effects are gastrointestinal disorders, mouth ulcers, dry cough, rough mucous membranes such as throat, suffocation, malaise, easy hair loss when washing hair, easy internal bleeding, difficult physiological bleeding, and liver function numbers.
There is a rise in.
On the other hand, these side effects are also a sign that the drug is working well in the body (the concentration is rising well), so if it is mild, you do not have to worry too much.
Have them take a vitamin supplement called folic acid (trade name: Foliamine) to reduce side effects. When taken with MTX, it diminishes the anti-rheumatic effect. At this hospital, one tablet (5 mg) is taken the day before and the day after taking MTX.
The role of folic acid
It suppresses the side effects caused by MTX.
It suppresses side effects caused by rheumatism drugs such as gastrointestinal disorders.
Precautions for taking methotrexate
Patients at our clinic are instructed to take them in bulk on Saturday and Sunday mornings. Please note that the dosage is slightly different from the one described in the package insert.
If you have a good understanding of the nature of the medicine, you can arrange the way of taking it to suit your individual needs as follows.
You can change the day of the week so that you don't forget to take it.
The days of the week are not exact, so if you miss a dose, you can take it the next day.
All you have to do is keep the amount you take during the week.
Although it is supposed to be after breakfast, it can be taken once or divided into two times, either after breakfast, lunch or supper.
●MTX Pneumonia-Hitoshi Tokuda Rheumatoid Arthritis Vol. 42, No. 5: 516-224. 2009/11 Special Feature The latest findings for the effective and safe use of methotrexate
●Methotrexate pharmacokinetics and drug interactions-Shunsuke Mori Rheumatoid Arthritis Vol. 42, No. 5: 471-479. 2009/1
Rheumatoid arthritis Q & A regarding the use of methotrexate
We answer many questions about taking methotrexate (MTX). I hope it will be an opportunity for patients who start RA treatment using MTX to deepen their understanding.
- (While visiting another hospital) I was using MTX and it worked well, but I continued to have a dry cough, so I took an X-ray of my chest. There was no abnormality, but it was canceled due to the risk of interstitial pneumonia.
- There are many side effects of MTX, but the key word to explain this is mucosal damage. This explains many side effects such as gastrointestinal disorders, mouth ulcers, cheilitis, and bleeding from the vaginal mucosa. Since the throat (pharynx and larynx) does not leak and the surface is mucous membrane, complaints such as difficulty in swallowing, tingling, and dry cough are seen from beginning to end. Immediately, without panicking for pneumonia, if chest x-rays and blood tests show that pneumonia is unlikely, you should add it if you are not taking folic acid, and if the symptoms are not severe, follow the course with symptomatic treatment.
- I started taking MTX, but on the first day I took it, I felt sick and felt like I was going back. I heard that it was a strong drug, so I was scared and stopped. When I consulted with my teacher, I was told that it didn't suit you, so I decided to cancel. Instead, I'm using a lighter drug with fewer side effects, but rheumatism seems to be getting worse and worse after that. When I started using MTX, I stopped using it because my blood test after 4 weeks told me that my liver function was increasing. After all RA is getting worse.
- When using MTX, it is strongly recommended to always use folic acid together from the beginning. Folic acid, a vitamin, is often deficient even in healthy people, and when MTX is administered to it, gastrointestinal disorders and liver dysfunction occur at a high rate. Once you feel uncomfortable, the patient has a strong sense of fear that it is a strong drug, and often stops it. MTX is a drug that is far more effective than other drugs. If you give up using MTX, you may take away your chances of getting rid of RA.
- What is the difference between MTX (Rheumatrex and Methotrexate)?
- Since Rheumatrex is a capsule, it is absorbed in the gastrointestinal tract at a lower rate in some people than in tablets of methotrexate, and in some cases it is less effective. For this reason, most patients at our hospital use tablets of methotrexate. On the other hand, methotrexate is prone to gastrointestinal disorders, so some patients desire rheumatrex.