E069 Preventing co-prescription of methotrexate with trimethoprim containing medicines in paediatric rheumatology

Abstract Background/Aims Co-prescribing of low-dose methotrexate and trimethoprim or co-trimoxazole is associated with bone marrow suppression. Pancytopenia has been reported in patients treated with co-trimoxazole shortly after discontinuation of methotrexate. In response to a serious incident documented elsewhere in the Trust, the Great North Children’s Hospital Paediatric Rheumatology team undertook a quality improvement project designed to reduce the risk of co-prescribing methotrexate and trimethoprim/co-trimoxazole in paediatric rheumatology patients. Methods The paediatric rheumatology team identified all children and young people (CYP) under their care on methotrexate, reviewing hospital electronic records for advice to families and/or primary care regarding the risks of trimethoprim/co-trimoxazole. The team worked together to build an improved approach to safety. Following implementation of the improved pathway, the team reviewed their work. Results In January 2023, the paediatric rheumatology team identified 90 patients on methotrexate. Although a small number of patients had evidence of advice relating to co-prescription of trimethoprim/co-trimoxazole, advice was reactive and inconsistent. The following intervention pathway was devised: (i) To prevent hospital co-prescribing, a ‘sensitivity to trimethoprim’ flag was added to the hospital electronic prescribing system. Flag to be removed upon cessation of methotrexate. (ii) To prevent primary care co-prescribing, a standard paragraph was added to all clinic letters for CYP on methotrexate: Action for GP - Methotrexate to be added to patient medication list as ‘Hospital issue only’. (iii) The methotrexate counselling process was updated to include verbal and written information about avoiding trimethoprim/co-trimoxazole whilst on methotrexate. In December 2024, 115 people were included in an audit of the intervention. Eighty-four were on methotrexate and 31 had stopped treatment from July-December 2024. In 43/84 (51%) of patients on treatment, the most recent clinic letter mentioned ‘Action for GP’. In 75/84 (89%) of patients on treatment, the sensitivity was recorded on electronic records. The removal of trimethoprim sensitivity was completed in 28/31 (90%) of children that had stopped methotrexate. Two incidents of co-prescription were noted post intervention. One involved GP prescription of trimethoprim for UTI prophylaxis, and one involved GP prescription of trimethoprim for treatment of UTI where interaction warnings flagged were ignored. Harm was prevented by intervention from the team for one and a parent for another. Conclusion Co-prescribing of methotrexate and trimethoprim/co-trimoxazole is an important safety concern. This audit described the Newcastle approach to improving safe prescribing. The intervention effectively prevented co-prescribing in the hospital setting but asking GPs to flag the possible interaction on their records was not consistently effective. This is a challenging area and our improvement project illustrates that further primary care education is needed. The absence of a unifying NHS IT system is a barrier to improvement. Disclosure K. Hartley: None. L. Craig: None. S. Cairns: None. J. Hutchinson: None. F. McErlane: None. S. Sampath: None. E.S. Sen: None. S. Jandial: None.