Hypersensitivity Reactions to Proton Pump Inhibitors

Abstract

Proton pump inhibitors I Drug allergy I Anaphylaxis I Adverse drug reaction I Drug hypersensitivity Opinion Statement Proton pump inhibitors (PPIs) are drugs widely used and usually well tolerated. However, cases of immediate or cell-mediated hypersensitivity reactions due to all PPIs, with the exception of the newest dexlansoprazole and tenatoprazole, have been described. In the case of suspected IgE-mediated reaction skin test (prick test and intradermal test) with nonirritant drug concentration published is safe and highly specific (100 %) with a PPV of 100 %. Thus, oral provocation test should be performed only in case of negative results to rule out definitely the diagnosis. In the case of possible cell-mediated hypersensitivity reaction, a delayed reading of intradermal test, at least after 24 and 48 h, and patch test should be performed, but we do not have standardized procedures so far. Cross-reactivity among all PPIs is not a dogma, in fact, three patterns of cross-reactivity have been described. Thus, in patients with ascertained allergy to a PPI, a complete evaluation (skin test and oral provocation test) of all five PPIs available helps to identify a safe alternative.

Management of Hypersensitivity Reactions to Proton Pump Inhibitors: A Retrospective Experience

“…Anaphylaxis was also frequent in the previous reports [12,19,20]. The latency time between the last drug intake and the reaction was ≤1 h in 85% and 1-7 h in 10% of the study patients.…”

“…Based on these data, we did not perform confirmatory OPTs in patients with skin test positivity to the culprit or alternative PPIs. Similarly, in a recent review, the authors suggest that, given the very high specificity and PPV of skin testing in cases of suspected IgE-mediated reactions, OPTs should be performed only in cases of negative results, to rule out the diagnosis [19]. …”

“…Omeprazole, esomeprazole and pantoprazole have changes in their benzimidazole rings whereas lansoprazole and rabeprazole have modification in their pyridine rings [19]. Four general patterns of cross-reactivity, which could be explained by the chemical structure of PPIs, have been identified based on the published articles: whole-group hypersensitivity, omeprazole-esomeprazole-pantoprazole hypersensitivity, lansoprazole-rabeprazole hypersensitivity, and selective sensitization to a single PPI [19]. Although we could not perform a full analysis of cross-reactivity with all PPIs in most of our cases, 10/21 patients with a positive definitive diagnosis showed at least 1 cross-reactivity.…”

Case of anaphylaxis to lansoprazole confirmed by histamine release test and oral provocation test

“…Approximately 180 cases of type-1 reactions to PPI, including anaphylaxis by LPZ, have been reported. 3 However, proof of type-1 reaction to PPI is difficult, because PPI are often used with other drugs. 3 The skin test is reasonably safe and sensitive to detect type-1 hypersensitivity to the culprit drug, 4 but may result in negative.…”

“…3 However, proof of type-1 reaction to PPI is difficult, because PPI are often used with other drugs. 3 The skin test is reasonably safe and sensitive to detect type-1 hypersensitivity to the culprit drug, 4 but may result in negative. OPT, which is the most reliable approach for accurate diagnosis, but can be time-consuming and is accompanied by a risk of developing fatal shock.…”