Reducing blood testing for non-biologic DMARDs? Yes Please!

Hands up who thinks we do too many monitoring blood test? Yup me too. I’m sure I’m not the only one who, when checking my path inbox, has reflected that the majority of the blood tests I am reviewing seem to be for chronic disease checks or drug monitoring. It’s one of the vicious cycles we get into in medicine when we’re so busy that we just keep doing things, just because ‘we always have’, without standing back and thinking ‘do we really need to keeping doing this?’. 

Never is this more true than of blood monitoring for disease modifying anti-rheumatic drugs (DMARDs). So it was a welcome breath of fresh air when the British Society for Rheumatology (BSR) published their updated their guideline on DMARD monitoring in 2026, with the headline change being ‘A notable change in these updated recommendations compared with the 2017 guideline is the relaxation of the previously more frequent monitoring schedule’. Sounds good, tell me more…

Stable patients without risk factors for toxicity may be able to extend blood monitoring schedules

It’s important to clarify that this guideline refers to conventional synthetic DMARDs (csDMARDs) - previously known as ‘non-biologic DMARDs’ e.g. methotrexate, leflunomide, and does NOT refer to the biological DMARDs e.g. infliximab, etancercept. The guideline highlights the need to balance patient safety with the ‘burden of unnecessary testing’. For maintenance schedules, which are very much relevant to us, the BSR recommend that for those patients stable on treatment without risk factors for toxicity, monitoring intervals may be extended up to 6 monthly, and in some cases longer, depending on the csDMARD they are on.

The COVID-19 pandemic as a driver for change

One of the few upsides of the COVID pandemic was that it confirmed that relaxation of blood monitoring schedules for csDMARDs did not lead to harm for the majority of patients. Indeed I suspect this confirmed what many of us have thought for years, namely that there are a large number of people stable on csDMARDs having 3 monthly blood tests that really don’t need to. 

What’s the evidence to support relaxing blood monitoring schedules? 

Whilst there are no new direct trials comparing csDMARD monitoring strategies there is indirect evidence that for many people monitoring schedules can be relaxed. 

A retrospective UK primary care-based cohort trial (BJGP 2022; 72 (720)), which examined ~3000 patients with rheumatoid arthritis on methotrexate over 2 years, showed that over 50% had persistently normal blood tests over that period, and there are further observational studies which indicate that while laboratory abnormalities are common, they are often transient and rarely require permanent drug discontinuation, particularly after the first 12 months. 

The potential risk of a cytopenia is of course one of the reasons blood test monitoring is undertaken, but a retrospective case review of patients that developed methotrexate related myelosuppression showed they had no early warning signs on routine blood monitoring, as this often developed quickly and due to an intercurrent infection; the guideline group noted that early recognition of clinical features e.g. mouth or throat ulcers or mucositis, may be a better way of picking up impending cytopenia, rather than via routine blood tests.

There are always caveats…

However, we always needs to be aware of caveats - much of the evidence is for methotrexate and leflunomide monotherapy, and higher risk csDMARDs e.g. tacrolimus, ciclosporin will need ongoing monthly monitoring. Also, there are a number of risk factors for toxicity, which would rightly mean patients needing more frequent blood monitoring e.g. combinations of csDMARDs (notably if leflunomide and methotrexate are combined), those on other high risk drugs (e.g. anticoagulants, anti-epilpetic drugs), and those with multiple co-morbidities or poor renal function. The guideline thus recommends that people have an annual review to check for any new toxicity risk factors, so monitoring schedules can be adjusted if needed. 

Any changes in monitoring schedules are likely to need to be initiated by our rheumatology colleagues, but the hope is that shared care protocols will be adapted to be more individualised, and for those at low risk a significant reduction in blood testing is likely to be entirely appropriate, especially those stable on methotrexate monotherapy. Anything that reduce unnecessary burdens for our patients, and reduce unnecessary workload for us will be popular all round.