Detecting drug-related problems following metabolic and bariatric surgery using pharmacovigilance databases

Clinical data on changes in drug pharmacokinetics and pharmacodynamics following metabolic and bariatric surgery (MBS) remain limited and largely drug-specific. This study summarized cases of changed drug activity associated with MBS registered in the global pharmacovigilance database (VigiBase) and the Dutch pharmacovigilance database (Lareb), and assessed the utility of national and international data in identifying drug-related problems following MBS.

Individual case safety reports (ICSRs) involving MBS were extracted from VigiBase and Lareb. Exclusion criteria were age under 18, drug discontinuation after surgery, non-drugs, or non-bariatric surgery. Outcomes were classified as 'increased effect/adverse events', 'decreased effect/subtherapeutic', or 'unclassified'. For validation, we assessed whether Lareb ICSRs were retrieved in VigiBase and whether outcomes were similarly categorized in both datasets.

After deduplication and exclusion, 1112 ICSRs describing 1399 ICSR-drug combinations were retrieved from VigiBase: 752 (53.8%) were classified as 'increased effect/adverse event', 93 (6.7%) 'decreased effect/subtherapeutic', and 554 (39.6%) 'unclassified'. From Lareb, 80 ICSRs describing 81 ICSR-drug combinations were retrieved: 60 (74.1%) 'increased effect/adverse event' and 21 (25.9%) 'decreased effect/subtherapeutic'. 64 ICSR-drug combinations from Lareb were not found in the VigiBase dataset. Of the 17 matched ICSR-drug combinations, 13 (76%) were similarly classified. The most frequently reported drug classes were: H2-receptor antagonists, proton pump inhibitors, selective immunosuppressants, and other antidepressants.

Pharmacovigilance databases can identify potential drug-related problems following MBS. In this study, 'increased effect/adverse event' predominated following MBS. The Dutch pharmacovigilance data provided more detailed case information than the global VigiBase dataset, leading to differences in ICSR retrievals and outcome classifications. To improve the utility and complementarity of international pharmacovigilance data, access to medical history fields and the use of standardized queries are essential. Recording the year of MBS would also help assess possible changes in drug effects over time.