Inappropriate use of digoxin in elderly patients presenting to an outpatient cardiology clinic of a tertiary hospital in Turkey

OBJECTIVES
We investigated the prevalence and indications of digoxin use in elderly patients presenting to a cardiology outpatient clinic of a tertiary hospital in Turkey.

STUDY DESIGN
On a prospective basis, the study included 800 consecutive patients aged 70 or over (mean age 77±6 years) who presented to our cardiology outpatient clinic. There were 124 patients (15.5%) receiving digoxin. All the patients underwent transthoracic echocardiography. Digoxin use was considered inappropriate if the patient had normal left ventricle systolic function or if there was no atrial fibrillation (AF).

RESULTS
The reasons for use of long-term digoxin were persistent AF (n=55, 44.4%), heart failure (HF) (n=51, 41.1%), and paroxysmal AF (n=8, 6.5%). The exact reason could not be determined in 10 patients (8.1%). Digoxin use was based on appropriate indications in 76 patients (61.3%), whereas 48 patients (38.7%) were taking digoxin with inappropriate indications. Of 51 patients for whom HF was the only reason for digoxin therapy, diagnosis of HF was incorrect in 30 patients (24.2%). Other inappropriate indications were paroxysmal AF and undetermined indication for digoxin prescription. Concerning digoxin dose, 24 patients (19.4%) received one tablet (0.25 mg) and 30 patients (24.2%) received a half tablet (0.125 mg) on a daily basis, while 10 patients (8.1%) used six tablets per week with one day off (0.214 mg/day) and 60 patients (48.4%) took five tablets per week with two days off (0.179 mg/day). The median daily dose was 0.182 mg/day. Digoxin dose was higher than the recommended doses for elderly patients in 75.8% of the patients.

CONCLUSION
Our findings show that nearly 40% of elderly patients receive digoxin with inappropriate indications and 75% of these patients take digoxin at higher doses than the recommended doses for this age group.