Lack of age-related differences in the clinical presentation of digoxin toxicity.
BACKGROUND
Digoxin toxicity occurs most commonly among the elderly. While the clinical syndrome of digoxin toxicity is well understood, how toxic manifestations change with age is not known.


METHODS
We performed secondary analysis of data from a postmarketing surveillance study of patients with life-threatening digoxin toxicity treated with digoxin antibody therapy. Patients receiving long-term maintenance digoxin therapy and aged 55 years or older were divided into four age groups: 55 to 64, 65 to 74, 75 to 84, and 85 years and older (n = 45, 167, 183, and 83, respectively) and compared with regard to presenting manifestations, digoxin dosing, serum potassium and digoxin levels, and renal function.


RESULTS
The prevalence of high-degree atrioventricular block showed an increasing but nonsignificant trend with age (40%, 40%, 42%, and 47%, respectively). Age-related trends in high-degree atrioventricular block were stronger among men than women and even stronger among men with underlying cardiac ischemia. The proportion of subjects with nausea/vomiting as a toxic manifestation did not consistently change with age (42%, 48%, 48%, and 46%, respectively). There were no age-related differences in degree of renal impairment or maintenance dose, but maintenance dose decreased with increasing renal impairment.


CONCLUSIONS
Among patients with life-threatening digoxin toxicity, there is no age-related difference in clinical presentation.
Wofford
J L
JL
Department of Internal Medicine, Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, NC 27103.
Hickey
A R
AR
Ettinger
W H
WH
Furberg
C D
CD
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001145:Arrhythmias, Cardiac / Q000139:chemically induced; D004077:Digoxin / Q000276:immunology / Q000506:poisoning*; D005260:Female; D006327:Heart Block / Q000139:chemically induced; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009325:Nausea / Q000139:chemically induced; D011041:Poisoning / Q000453:epidemiology / Q000628:therapy; D015995:Prevalence; D011358:Product Surveillance, Postmarketing; D014839:Vomiting / Q000139:chemically induced
D007140:Immunoglobulin Fab Fragments; C050199:digoxin antibodies Fab fragments; D004077:Digoxin