Abstract
Background Bullous pemphigoid has been associated to dipeptidase-4 inhibitors. Objectives Addressing the potential Bullous pemphigoid-dipeptidase-4 inhibitors association based on pharmacovigilance data currently available in Spain in order to obtain a composite disproportionality estimator from all the data generated by the case-non case studies conducted to this date. Setting The Spanish Pharmacovigilance System for Human Use Drugs database. Method Case-non case study based on the Spanish Pharmacovigilance System for Human Use Drugs notifications submitted between 2007 and 2018 (n = 169,280), using the Medical Dictionary for Regulatory Activities term (Preferred Term) 'pemphigoid' for sitagliptin, vildagliptin, saxagliptin, linagliptin, and alogliptin (n = 1952). As negative control, we used acetaminophen, while furosemide was the positive control. A pooled reported odds ratio analysis in the French, Japanese, and Spanish national pharmacovigilance databases was performed. On The Spanish Pharmacovigilance System for Human Use Drugs, we conducted a bullous pemphigoid-metformin association analysis within the period 1982-2018. Main outcome measure Adverse reaction cases in pharmacovigilance databases and the disproportionality through the reporting odds ratio. Results Within The Spanish Pharmacovigilance System for Human Use Drugs, we found 45 cases of bullous pemphigoid in dipeptidase-4 inhibitors patients. Median age was 77 years (range 72-82). The median latency period was 7 months (range 0.23-86). The Bullous pemphigoid-dipeptidase-4 inhibitors association was established with a reporting odd ratio = 70.0 (95% confidence intervals 49.1-10.1). In the combined analysis of the three aforementioned pharmacovigilance databases, the pooled reporting odd ratio was 81.0 (95% confidence intervals 69.5-94.4). Conclusion The composite estimator for the three national pharmacovigilance databases yields clear evidence of a Bullous pemphigoid-dipeptidase-4 inhibitors association, which was statistically significant for both the pharmacological class as a whole and each of the dipeptidase-4 inhibitors agents under investigation. Metformin's role in the incidence of bullous pemphigoid appeared casual rather than causal. No differences between Caucasian and Asian populations were noted.