Nawarskas J J, McCarthy D M, Spinler S A
Philadelphia College of Pharmacy and Science, PA 19104, USA.
Ann Pharmacother. 1997 Jul-Aug;31(7-8):864-6. doi: 10.1177/106002809703100711.
To report a case of digoxin toxicity thought to be secondary to clarithromycin therapy.
A 78-year-old white woman with congestive heart failure taking digoxin 0.25 mg po qd presented to our hospital with nausea, vomiting, and diarrhea. She had taken clarithromycin 500 mg po bid for 3 days, and a serum digoxin concentration obtained the day of admission was 4.4 mug/L. An electrocardiogram (ECG) done on admission revealed ST segment changes consistent with digoxin effect and later asymptomatic, nonsustained ventricular tachycardia (NSVT). Clarithromycin was discontinued and digoxin was withheld at admission, resulting in the resolution of symptoms, ECG abnormalities, and NSVT on day 3 of hospitalization. On day 5 her serum digoxin concentration was 1.5 micrograms/L and digoxin therapy was reinstituted at a dose of 0.125 mg/d po.
This is the fourth published case implicating clarithromycin as the cause of digoxin toxicity. This interaction is most likely due to clarithromycin eradication of digoxin-metabolizing gut flora, thereby increasing digoxin bioavailability.
Approximately 10% of patients are thought to be extensive presystemic metabolizers of digoxin and may therefore be most susceptible to a drug interaction with clarithromycin. Serum digoxin concentrations in such patients should be monitored closely during clarithromycin therapy.
报告一例被认为继发于克拉霉素治疗的地高辛中毒病例。
一名78岁白人女性，因充血性心力衰竭服用地高辛0.25mg口服，每日一次，因恶心、呕吐和腹泻入住我院。她已口服克拉霉素500mg，每日两次，共3天，入院当天测得血清地高辛浓度为4.4μg/L。入院时进行的心电图（ECG）显示ST段改变符合地高辛效应，随后出现无症状、非持续性室性心动过速（NSVT）。入院时停用克拉霉素并停用了地高辛，住院第3天症状、心电图异常和NSVT消失。第5天，她的血清地高辛浓度为1.5μg/L，重新开始地高辛治疗，剂量为0.125mg/d口服。
这是第四例报道的提示克拉霉素为地高辛中毒原因的病例。这种相互作用很可能是由于克拉霉素消除了代谢地高辛的肠道菌群，从而增加了地高辛的生物利用度。
约10%的患者被认为是地高辛的广泛首过代谢者，因此可能最易发生与克拉霉素的药物相互作用。在克拉霉素治疗期间，应密切监测此类患者的血清地高辛浓度。
