Abstract
BackgroundDisease-modifying anti-rheumatic drugs (DMARDs), including methotrexate and azathioprine, are commonly used to treat rheumatoid arthritis (RA) and inflammatory bowel disease (IBD). Blood-test safety monitoring is mainly undertaken in primary care. Normal blood results are common.AimTo determine the frequency and associations of persistently normal blood tests in patients with RA prescribed methotrexate, and patients with IBD prescribed azathioprine.Design and settingTwo-year retrospective study of a cohort taken from an electronic pseudonymised primary care/laboratory database covering >1.4 million patients across Hampshire, UK.MethodPatients with RA and IBD, and associated methotrexate and azathioprine prescriptions, respectively, were identified. Tests and test thresholds recommended by the National Institute for Health and Care Excellence were applied. Persistent normality was defined as no abnormalities of any tests nor alanine aminotransferase (ALT), white blood count (WBC), neutrophils, and estimated glomerular filtration rate (eGFR) individually. Logistic regression was used to identify associations with test normality.ResultsOf 702 265 adults, 7102 had RA and 8597 had IBD. In total, 3001 (42.3%) patients with RA were prescribed methotrexate and 1162 (13.5%) patients with IBD were prescribed azathioprine; persistently normal tests occurred in 1585 (52.8%) and 657 (56.5%) of the populations, respectively. In patients with RA on methotrexate, 585 (19.5%) had eGFR, 219 (7.3%) ALT, 217 (7.2%) WBC, and 202 (6.7%) neutrophil abnormalities. In patients with IBD on azathioprine, 138 (11.9%) had WBC, 88 (7.6%) eGFR, 72 (6.2%) ALT, and 65 (5.6%) neutrophil abnormalities. Those least likely to have persistent test normality were older and/or had comorbidities.ConclusionPersistent test normality is common when monitoring these DMARDs, with few hepatic or haematological abnormalities. More stratified monitoring approaches should be explored.
Highlights
Persistent test normality is common in monitoring these Disease-modifying anti-rheumatic drugs (DMARDs) in primary care, with few hepatic or haematological abnormalities
More stratified monitoring approaches should be explored. How this fits in Conventional synthetic disease-modifying anti-rheumatic drugs (DMARDs) such as methotrexate and azathioprine are commonly used to treat rheumatoid arthritis (RA) and inflammatory bowel disease (IBD) in the UK
Their ongoing prescribing and blood test safety monitoring are mainly undertaken in primary care
Summary
Rheumatoid arthritis (RA) and inflammatory bowel disease (IBD) are common inflammatory conditions with prevalence of 0.8% (0.4% in men, 1.2% in women) and 0.7% (ulcerative colitis about 0.4%, Crohn’s disease 0.3%) respectively.[1,2] Disease-modifying anti-rheumatic drugs (DMARDs), including synthetic and biological agents, are used to control disease activity and progression.[3,4,5,6] The commonest synthetic DMARDs in the UK are methotrexate for RA and azathioprine for IBD.[3,4,5] Both require regular safety blood test monitoring for liver function abnormalities, kidney function and bone marrow toxicity, frequently at initiation and less frequently once a maintenance dose is established.[7] In the UK methotrexate or azathioprine initiation usually occurs in secondary care with blood test monitoring and on-going repeat prescribing undertaken in primary care as recommended by the National Institute for Health and Care Excellence (NICE).[7,8] Guidelines include recommendations to ‘consider stopping treatment and referring urgently’ if results show abnormalities.[7,9] Regular blood test monitoring has been linked with anxiety and depression for some patients and incurs substantial costs for healthcare providers, and workload for clinicians, laboratory staff and administrators.[10,11,12,13] Despite guidelines, the optimal monitoring frequency has not been established.[3,4,5,6] The extent to which patients taking DMARDs experience prolonged periods with no abnormal tests is unclear.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
