Background and importance Biologic drugs are essential in the treatment of inflammatory bowel diseases (IBD) but it is necessary to individualise these therapies for optimal disease control. Pharmacokinetics have been shown to be useful for this aim.

Aim and objectives To analyse the clinical impact of adalimumab adjustment through pharmacokinetics and clinical parameters in IBD control.

Material and methods A longitudinal prospective study was conducted in a second level hospital in 2019, from June to December in patients with IBD treated with adalimumab that passed the induction phase. Data collected were sex, age and analytic parameters before and after treatment adjustment: plasma adalimumab levels and anti-adalimumab antibodies (ADAs) and previous adalimumab administration. Acute phase reactants (APR) were measured: C reactive protein (CRP), α-acid-glycoprotein (AGP) and faecal calprotectin. Overall patient status was obtained from the digital physician report; this parameter was reported as symptomatic or asymptomatic. We did one intervention per patient.

Interventions proposed were: treatment intensification (increasing dose and/or decreasing administration time), treatment deintensification (increasing administration time), drug change with same therapeutic target (SWITCH) and drug change with different therapeutic target (SWAP). The Student´s t test for correlated groups was performed but any intervention involving SWAP or SWITCH was excluded. Asymptomatic patients without altered APR and optimal plasma adalimumab concentrations maintained the same treatment scheme. Results

89 patients were analysed and 41 (46%) patients were proposed and accepted for interventions, of whom 22 (54%) were men with a mean age of 40 years (18–66). The data are shown in table 1. Interventions performed: 21 (51%) deintensification, 10 (24%) intensification, 7 (17%) SWAP and 3 (7%) SWITCH. Symptomatic patients before interventions totalled 19 (46%); after the interventions 4 (10%) patients remained symptomatic, 3 after intensification and 1 after a treatment SWITCH.

Conclusion and relevance APR improved after interventions. Faecal calprotectin showed a significative p value. Further studies are required. Monitoring adalimumab along with clinical patient data is crucial to optimise IBD control. This practice is effective, safe and contributes to the sustainability of the health system, saving possible adverse effects and money. Clinical pharmacists have a crucial role in optimal clinical patient development.

Conflict of interest No conflict of interest