一位71 歲男性病人，因為脹氣、嘔吐、體重減輕到院治療，初步診斷為胃食道逆流及胃潰瘍，經確診為胃癌後進行手術切除腫瘤。病人住院期間總共使用了38 天的靜脈注射pantoprazole，使用數日內血小板計數即快速降低，從第一天住院時的526 × 103/μL 下降到第35 天的3 × 103/μL，期間給予大量的血品補充血小板亦未有改善。病人在停止注射pantoprazole 並轉換成口服esomeprazole 後，血小板低下症迅速獲得緩解且逐日回復正常。本案例在提醒醫療人員，對於使用pantoprazole 與血小板低下症之關聯應提高警覺，使用pantoprazole 時小心監測血球數之變化，若有異常應提早進行必要之處置。

A 71-year-old man was admitted to our hospital with bloating, vomiting, and weight loss. He was first diagnosed as having gastro-esophageal reflux disease and gastric ulcer; gastric cancer was later confirmed. During the patient’s hospital stay, he received intravenous pantoprazole for 38 days. The patient developed thrombocytopenia soon after the initiation of pantoprazole. His platelet count dropped from 526 × 103/μL on admission day to 3 × 103/μL on day 35, despite massive transfusion of blood products given concomitantly. The patient’s thrombocytopenia resolved rapidly after the discontinuation of pantoprazole. Moreover, the patient did not have thrombocytopenia when oral esomeprazole was substituted. This case report suggests that vigilance of the association between pantoprazole and thrombocytopenia should be maintained. Close monitoring and early management of patients receiving pantoprazole therapy are crucial.