RESUMEN
OBJECTIVE: To report 2 cases of thrombocytopenia associated with pantoprazole treatment and discuss existing reports on this drug-induced adverse event. CASE SUMMARIES: This paper describes the course of thrombocytopenia associated with pantoprazole 40 mg in 2 hospitalized patients. In both cases, thrombocytopenia appeared after the initiation of pantoprazole and rapidly improved after discontinuation of pantoprazole, although complete resolution of thrombocytopenia occurred in only one patient prior to discharge from the hospital. DISCUSSION: The mechanism of drug-induced thrombocytopenia is often poorly understood, and proton-pump inhibitors are generally not strongly suspected as a cause of thrombocytopenia. However, an objective causality assessment using the Naranjo probability scale revealed a probable relationship between thrombocytopenia and pantoprazole in both of the cases. It is unknown whether this is a class effect. CONCLUSIONS: Although drug-induced thrombocytopenia with pantoprazole appears to be rare, it represents a potentially severe adverse effect. This supports the judicious prescribing of pantoprazole and possibly other proton-pump inhibitors.