Methotrexate for RA

Methotrexate is one of the Disease Modifying Anti-Rheumatic Drugs that can be prescribed to treat rheumatoid arthritis.  It is usually prescribed along with folic acid (to reduce the possibility of mouth sores).

Other DMARDs such as plaquenil and sulfasalazine take two months or more to begin working.  Methotrexate can show results in as little as three weeks – although six weeks, or up to six months can be needed to get the full benefit.

Methotrexate comes in both pills and an injectable form.  The pills are tiny – only one-quarter of an inch in diameter:

People sometimes read the side-effects list on this medicine and are concerned.  That list sounds pretty scary!  Not to worry.  The list of side-effects includes things that most people don’t experience.  When you’re given a prescription, it’s because your doctor believes that the chances the medicine will help you are greater than the chances that there will be serious side effects.  Here’s a great info sheet by one doctor.

Side effects tend to be dose-related.  That means the higher the dose, the greater the chances for adverse reactions.  RA patients are taking a much lower dose than cancer patients, so most of the potential side effects listed will not be a problem for people who are taking mtx for RA.

When I wrote previously about mtx side effects (here and here and here), I said it would be interesting to look back in a year to see if my perspective had changed.  It’s already changed.

Anemia, low white blood cell count, and low platelet count.

Yes, these lab results are all lower than they were before mtx.  It doesn’t seem to be a causing any problems, though.

Risk of infection.  Avoid people with infections, colds, or flu.

One article I read said that rates of infection among those taking mtx are similar to those seen in the general population.  The difference is that those in the general population have an immune system that can fight infection.  RA patients taking immunosuppressants have a harder time fighting infections, so are supposed to phone the doctor and get early treatment.

Nausea or vomiting.  Small frequent meals, frequent mouth care, sucking hard, sugar-free candy, or chewing sugar-free gum may help.

I’m now taking double the dose that I was in the beginning and don’t have any trouble with nausea or dizziness.  This was only a problem for the first 3-4 weeks.  Taking mtx at bedtime so you sleep through the worst of the side effects can help.  Dehydration can make it worse, so make sure you’re drinking plenty of water.

Not hungry.

I still don’t see why this is considered a problem.

Diarrhea.

Thankfully, this hasn’t been an issue.

Mouth irritation.  Frequent mouth care with a soft toothbrush or cotton swabs and rinsing mouth may help.

Mouth sores that occur with mtx use are thought to be from a folic acid deficiency.  Taking prescription-strength folic acid helps.  I’ve heard from a few people whose doctor recommended increasing to 2 mg daily when they still got mouth sores on 1mg.

Headache.

Headaches were quite severe the first couple weeks, but are no longer a problem.  I suspect that taking this at bedtime helps.

Hair loss.  Hair usually grows back when medicine is stopped.

I didn’t notice any problem with this.  Hair loss was significant a few years ago without methotrexate.  It seems to be back to normal now.

Liver damage can rarely occur.

This is one of the reasons that monthly lab work is done.  Problems are unlikely, but if they occur, should show in the lft’s before symptoms become a problem.  Reducing the dose (or discontinuing temporarily) helps.

Alcohol use is hard on the liver, so doctors usually recommend abstaining from alcohol if you’re taking mtx.

Lung damage can rarely occur.

It’s more common for RA to affect the lungs than it is for methotrexate to cause lung problems.  Doctors take x-rays and a good history before beginning mtx in an effort to identify those most likely to have lung complications.  There’s a study linked at the bottom if you’re interested in reading more.

Other forms of cancer can rarely occur later in life.

The risks are still pretty small.

More Reading:

Ten Things You Should Know About Mtx
Risk Factors for Methotrexate-Induced Lung Injury in Patients with Rheumatoid Arthritis: A Multicenter, Case-Control Study

Additional methotrexate information:
American College of Rheumatology
NIH/MedLine Plus
RheumInfo
RxList
UpToDate
MedicineNet