Digoxin臨床上常用於心臟衰竭及心房纖維顫動的病人，因治療範圍狹窄，故需長期監測血中濃度，但臨床上中毒的情形仍常發生於長期慢性服用的病人；相對來說，急性大量服用digoxin造成中毒的病人是極為少見。本文探討一位沒有心臟衰竭且腎臟功能正常，之前從未服用digoxin的患者，蓄意服用約200顆0.25 mg的digoxin，之後產生噁心、嘔吐的症狀且心電圖呈現2：1房室傳導阻礙，血中digoxin濃度於服用九小時後上升至10.01 ng/mL（正常digoxin血中濃度值為0.5-1.5 ng/mL），但鉀離子並無明顯上升。給予digoxin immune Fab （digibind®）治療後，digoxin血中濃度在7小時內快速地下降至3.51 ng/mL，並於34小時內digoxin血中濃度降至治療範圍，雖然心電圖在四天住院期間內並無明顯變化，但一個月後以電話追蹤，其並無明顯不適的治療成功案例。文中對digoxin中毒的毒理學、藥理學、藥物動力學、治療方式及digoxin immune Fab投與時機及之後digoxin血中濃度監測的方式做討論。如何適時適量的給予digoxin immune Fab來治療digoxin中毒，可說是digoxin中毒治療中最重要的課題，使用digoxin immune Fab的時機除了考慮經濟效益外，更應暸解投與digoxin immune Fab的急迫性與否及可能出現的反效果，而不是過度的使用於任何digoxin過量的情況，如此才能使digoxin immune Fab適得其所的使用。

Digoxin is usually used in treating patients with congestive heart failure and atrial fibrillation. It needs to monitor serum level regularly due to its narrow therapeutic range, Nevertheless, digoxin intoxication still occurs in chronic users. On the contrast, acute massive dosage intoxication is relatively rare. We report a patient case with no heart failure history, normal renal function and where digoxin was never taken previously; who intensively took 200 tablets of 0.25 mg digoxin. Nausea and vomiting was noted soon after and electrocardiography showed 2:1 second-degree atrioventricular block. Serum digoxin level reached 10.01 ng/mL (normal range 0.5-1.5 ng/mL) after 9 hrs of intake, although serum potassium level was not elevated. Digoxin immune Fab (digibind®) was given and serum digoxin level dropped to 3.51 ng/mL 7 hrs later and to therapeutic levels 34 hrs later. Although the electrocardiograph did not change during the 4 days of hospitalization, follow-up by telephone one month later indicated the patient had recovered well. In the article, we discuss the toxicology, pharmacology, pharmacokinetics of digoxin and treatment of digoxin intoxication and the most appropriate times when to use digoxin immune Fab and how to monitor digoxin serum level after digoxin intoxication. Knowing how to use digoxin immune Fab to treat digoxin intoxication at the right time and with the right dosage without overuse is the most important issue. Besides considering the economic effects, we also need to know the possible side effects of digoxin immune Fab and if there is any urgency for using it.