Outcomes of a drug shortage requiring switching in patients with ulcerative colitis.

Background: Drug shortages are common yet their impact on patient care and their commercial ramifications has not been adequately researched. In Australia a shortage of balsalazide (2012-2013) necessitated substitution with alternative 5-aminosalicylate (5-ASA) formulations for ulcerative colitis (UC).

Aim: To assess and compare the clinical and commercial sequelae of non-medical switching from balsalazide to another 5-ASA and/or return to balsalazide once supply resumed.

Methods: A prospective cohort study of patients on balsalazide for mild-moderate UC was conducted where, strictly due to the national shortage (November 2012- January 2013), were switched to alternative 5-ASA and/or then returned to balsalazide once supply resumed. Clinical (Partial Mayo), endoscopic (Mayo score) activity, adverse effects (to alternative 5-ASA) and percentage market share (of continuous 5-ASA users) from baseline (i.e., time of switching due to shortage) through to five years were assessed.

Results: Of 31 patients switched due to the shortage, 12 (38.7%) resumed balsalazide immediately once supply resumed, 8 (25.8%) prompted by adverse effects to the alternative 5-ASA used. Three patients (9.7%) had documented symptomatic improvement, 15 (48.4%) were unchanged and 13 (41.9%) had symptomatic worsening vs baseline (P < 0.01), after switching to an alternative 5-ASA. At 3 and 5y post switch, overall 26/31 (83.9%) and 23/31 (74.2%) had remained continuously on any 5-ASA therapy respectively. Twelve (38.7%) and 11 (35.5%) patients remained on balsalazide continuously at three and five years respectively after drug supply returned, equating to a loss of market share (within 5-ASA class) of 45.2% and 38.7% respectively.

Conclusion: This study of a balsalazide shortage in UC patients exemplifies the detrimental impact of a drug shortage on long term patient, disease and commercial outcomes.