Background and importance Infliximab (IFX) is a monoclonal antibody (inhibitor of alpha tumour necrosis factor (anti-TNFα)) which is used in the management of inflammatory bowel disease (IBD). However, some patients do not show clinical benefit for this therapy or they show loss of response over time. For this reason, it is advisable to individualise and optimise the therapy through therapeutic drug monitoring (TDM).

Aim and objectives To analyse the clinical situation of patients according to proactive monitoring of serum levels of IFX in IBD and pharmacokinetic recommendations in their management.

Material and methods A prospective study was carried out in a 350 bed general hospital. Patients with IBD and IFX determinations with pharmaceutical interventions performed between January 2019 and July 2020 were selected. Data collected were: sex, median age (range), analytical parameters before intervention (mean (SD) albumin, C reactive protein (CRP), α1-acid glycoprotein (AGP), faecal calprotectin (FC)) and clinical status before intervention (good general condition (GGC), regular general condition (RGC) and bad general condition (BGC)). Mean (SD) IFX levels and anti-IFX antibodies (ATI) were measured and patients with concomitant immunomodulatory treatment were registered. According to population studies, new interventions were recommended by the pharmacy service (intensification, swap, deintensification, non-valuable). Analytical parameters (CRP, AGP, FC) and clinical status of the patient 3 months after the intervention were analysed. Data were obtained from the assisted electronic prescription programme and digital medical records.

Results 55 patients with interventions were monitored, 38 men (69.1%), mean age 39 (20–70) years. Analytical parameters before the intervention were: albumin 4.04 (0.3) g/dL, CRP 0.78 (0.75) mg/dL, AGP 87.35 (29) mg/dL and FC 190.25 (148.61) µg/g. Clinical status before the intervention was GGC 9 (19.36%), RGC 30 (54.55%) and BGC 16 (29.11%). IFX levels were 3.04 (4.22) µg/mL and ATI 1.48 (2.61) µg/mL. Patients with concomitant immunomodulatory treatment 32 (58.18%). All recommended interventions were accepted: intensification 41 (74.55%), swap 10 (18.18%), deintensification 3 (5.45%) and non-evaluable 1 (1.82%). Analytical parameters 3 months after the intervention were: CRP 0.62 (0.64) mg/dL, AGP 85.21 (22.00) mg/dL and FC 174.75 (220.25) µg/g. Clinical status after the intervention was GGC 43 (78.18%), RGC 11 (20%) and BGC 1 (1.82%).

Conclusion and relevance After the intervention, patients showed a tendency to decreased inflammatory parameters and clinical improvement, with a subjective reduction in symptoms. TDM in association with recommendations of the pharmacy service are valuable strategies in optimising IBD treatment to avoid loss of response and achieve better clinical outcomes.

Conflict of interest No conflict of interest