Lansoprazole-induced microscopic colitis: An increasing problem? Results of a prospecive case-series and systematic review of the literature

Background: Microscopic colitis (MC), comprising lymphocytic and collagenous colitis (LC, CC), causes chronic diarrhoea. Lansoprazole can cause MC. Likelihood criteria defining the causative relationship between drugs and MC have not been applied to lansoprazole, nor has lansoprazole-related-MC been characterized. Aim: To analyse a series of lansoprazole-related MC cases, and characterize lansoprazole-related CC and LC. Methods: Cases were diagnosed over 23 months and causal relationship evaluated by established likelihood criteria. A systematic Medline search was conducted and publications analysed. Results: Eight patients had lansoprazole-related MC. In all cases chronological and causality likelihood scores supported lansoprazole causative role. Discontinuation determined resolution without further treatment. Twenty-five cases of lansoprazole-related MC from 10 publications were grouped with the present series, and differences between CC and LC analysed. CC cases had more macroscopic alterations at colonoscopy (72.2 vs. 6.6%; p= 0.0002). Time between lansoprazole start and symptoms onset was longer for CC (median 60 vs. 28 days; p= 0.03). Conclusions: Peculiar features of lansoprazole-related CC were described through the analysis of a newly diagnosed lansoprazole-related MC series in which the causative role of lansoprazole was for the first time defined by established likelihood criteria, and by pooled evaluation with other cases retrieved by a systematic literature review.