Digoxin toxicity compared with myocardial digoxin and potassium concentration.
1 Twenty-nine dogs were given digoxin (0.25 mg) by mouth twice daily for eight days. Some of them (group 1) also received diuretics and others (group 2) a mineralocorticoid. The dogs were then given an intravenous bolus injection of digoxin and plasma and cardiac muscle were analysed for digoxin and potassium. 2 In the digitalized dogs, myocardial potassium concentration decreased following the intravenous injection of either 0.05 or 0.15 mg/kg digoxin; in contrast, in those dogs given diuretics or mineralocorticoid the potassium concentration increased. 3 Ventricular arrhythmias occurred after digoxin injection (0.05 mg/kg) in the hypokalemic dogs, in those given a mineralocortocoid and in those dogs which received a toxic digoxin dose (0.15 mg/kg). No arrhythmias where seen in the control (digitalized) group. 4 Myocardial digoxin concentrations were similar in the control digitalized group and in the mineralocorticoid-treated dogs after the intravenous administration of the lower digoxin dose (0.05 mg/kg). The myocardial digoxin concentration was significantly higher in the hypokalemic group and in the group receiving the higher digoxin dose (0.15 mg/kg). 5 There was no obvious relationship between the occurrence of arrhythmias and the myocardial concentration of digoxin or potassium.
D000818:Animals; D001145:Arrhythmias, Cardiac / Q000139:chemically induced*; D004077:Digoxin / Q000009:adverse effects* / Q000097:blood / Q000378:metabolism; D004285:Dogs; D006439:Hemodynamics / Q000187:drug effects; D009206:Myocardium / Q000378:metabolism*; D011188:Potassium / Q000097:blood / Q000378:metabolism*; D012964:Sodium / Q000097:blood; D013997:Time Factors
D004077:Digoxin; D012964:Sodium; D011188:Potassium