Impact of a pharmacist-led thiopurine monitoring service in outpatients with inflammatory bowel disease

Background: Thiopurines are effective therapies for inflammatory bowel disease (IBD); however, treatment comes with safety concerns and adverse effects. Knowledge of the impact of pharmacists performing thiopurine monitoring is limited. Aims: To determine the impact of a pharmacist-led monitoring service in patients with IBD commencing thiopurine therapy managed in the ambulatory care setting. Methods: Patients commencing thiopurine therapy for IBD pre- and post-introduction of a pharmacist-led monitoring intervention were assessed. Pre-intervention patients received standard of care, while the post-intervention cohort was managed by the pharmacist. Data were acquired via retrospective audit of hospital medical records. The primary end-point was the proportion of patients with documented review for thiopurine adverse effects within the initial 3 weeks. Secondary end-points included achievement of therapeutic drug levels, persistence with thiopurine therapy, IBD-related episodes of care and number of outpatient medical reviews. Results: Pre- and post-intervention cohorts comprised of 37 and 33 patients respectively. Pharmacist intervention increased the proportion of patients with documented monitoring within 3 weeks from 8.1% to 84.8% (P < 0.01). No difference in thiopurine dose optimisation was seen (27% vs 27.3%). Persistence with thiopurine therapy increased from 65.7% to 87.9% (P < 0.03) at 6 months. IBD-related emergency department presentations were not significantly decreased (8.1% vs 3%; P = 0.62). No significant change was observed in hospital admissions (16.2% vs 12.1%; P = 0.74) or outpatient medical reviews. Conclusions: Pharmacist monitoring of thiopurine therapy initiation in IBD outpatients improves adverse effect monitoring and increases medication persistence.