Do I need blood tests while taking methotrexate for rheumatoid arthritis?

Yes, regular blood tests are essential while taking methotrexate for rheumatoid arthritis.¹²

Why Blood Tests Are Needed

Methotrexate can affect your liver, kidneys, and bone marrow. Regular monitoring helps your doctor catch potential side effects early before they become serious. The tests typically check:¹²³⁴⁵

• Liver function (enzymes like AST and ALT)
• Kidney function (creatinine)
• Blood cell counts (red blood cells, white blood cells, and platelets)¹²³⁴⁵

Typical Testing Schedule

While schedules can vary slightly depending on your rheumatologist or local guidelines (such as Bradford Teaching Hospitals NHS Foundation Trust), a standard monitoring timeline looks like this:

• When starting or increasing your dose: Every 2 weeks for the first few weeks (or every 2 to 4 weeks during the initial couple of months).¹²³
• Once stable: Every 3 months (though some long-term patients may extend up to every 6 months depending on individual risk factors).¹²³

Note: You should never take your weekly methotrexate dose if you have missed your required blood tests or if your doctor has told you to hold the medication due to abnormal results. ¹²To help tailor this information, are you just starting methotrexate or have you been taking it for a while? If you have experienced any specific symptoms or recent lab concerns, let me know.

Yes, blood tests are essential while taking methotrexate for rheumatoid arthritis (RA). Methotrexate can affect your bone marrow, liver, and kidneys, so regular monitoring is required to ensure the medication stays safe and effective for you.¹

What Blood Tests Are Needed?

The main routine tests your care team will track include:

• Full Blood Count (FBC): To check for changes in your red blood cells, white blood cells (which fight infection), and platelets (which help blood to clot).
• Liver Function Tests (LFTs): To monitor how your liver is processing the medication.
• Renal Function (Serum creatinine / eGFR): To check how well your kidneys are filtering waste from your blood.¹

How Often Will You Need Them?

The testing schedule typically changes depending on how long you have been on the medication and whether your dose has recently increased:

1. When starting or increasing the dose: You will need blood tests every 1 to 2 weeks initially to catch any early side effects right away.¹
2. During the first few months: Monitoring usually continues every 2 to 4 weeks as your body adjusts.¹
3. On a stable, long-term dose: Once your treatment is steady and well-tolerated, blood tests are typically spaced out to every 8 to 12 weeks (roughly every 2 to 3 months).¹

Key Signs to Watch For Between Tests

While regular blood tests do most of the heavy lifting, contact your rheumatology team or GP immediately if you develop warning signs like:

• A high temperature, chills, or signs of infection (e.g., severe sore throat)
• Unexplained bruising or bleeding
• Yellowing of the skin or eyes (jaundice) or dark urine
• Persistent nausea, vomiting, severe mouth ulcers, or a new dry cough / shortness of breath

You can review official guidance details on medication safety via the NHS Specialist Pharmacy Service Methotrexate Monitoring Guide.¹

To help tailor this information, how long have you been taking methotrexate, and how often is your clinic currently asking you to get your bloods done?

Yes. If you take methotrexate for rheumatoid arthritis, you need regular blood tests. They are an essential part of treatment, even if you feel well and aren't experiencing any side effects.

Methotrexate is effective at controlling rheumatoid arthritis, but it can sometimes affect your liver, kidneys and bone marrow (which produces blood cells). Blood tests help detect problems early, often before you notice any symptoms.

Which blood tests do you need?

There are three main areas doctors monitor:

1. Full blood count (FBC)

• Checks red blood cells, white blood cells and platelets.
• Detects anaemia and potentially dangerous reductions in blood cells.

2. Liver function tests (LFTs)

• Check for signs of liver irritation or damage.
• Methotrexate can sometimes increase liver enzymes.

3. Kidney function (U&E/eGFR)

• Checks how well your kidneys are working.
• Important because your kidneys help remove methotrexate from your body.

How often should you have blood tests?

In the UK, a typical monitoring schedule is:

The exact schedule depends on your individual risk factors and your rheumatology team's advice. The 2025 British Society for Rheumatology guidance also supports adjusting monitoring to individual risk. sps.nhs.ukdoi.org

When should you seek medical advice?

Contact your GP or rheumatology team promptly if you develop:

• Unusual bruising or bleeding.
• A severe sore throat or fever.
• Mouth ulcers.
• Yellowing of your skin or eyes.
• New or worsening breathlessness or a dry cough.

Seek urgent medical advice for severe symptoms.

One important point: Never assume you can skip blood tests because you've been taking methotrexate for years without problems.

Can I ask you two questions?

1. How long have you been taking methotrexate?
2. How often are you currently having blood tests – every month, every 3 months, or less frequently?

I can help you understand whether your current monitoring schedule is appropriate.