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Essentials of Diagnosis
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Intoxication may result from
Hyperkalemia common after acute overdose
Many different arrhythmias can occur
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General Considerations
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Chronic overingestion
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Differential Diagnosis
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Serum digoxin level (Note: Levels drawn within 6 h of ingestion may be falsely elevated before complete tissue distribution)
Serum potassium (frequent measures useful because they correlate with tissue effects)
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Diagnostic Procedures
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Ventricular arrhythmias: initially lidocaine, 2–3 mg/kg intravenously, or phenytoin, 10–15 mg/kg intravenously slowly over 30 min if digoxin-specific antibodies are not immediately available (see below)
Bradycardia: initially atropine, 0.5–2.0 mg intravenously, or transcutaneous external cardiac pacemaker
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After acute overdose, administer activated charcoal, 60–100 g orally or via gastric tube, mixed in aqueous slurry
Emesis not recommended because it may enhance vagotonic effects (eg, bradycardia, AV block)
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Repeated doses of activated charcoal, 20–30 g every 3–4 hours, may speed elimination of digitoxin (but not digoxin) by adsorbing drug excreted into gut lumen (gut dialysis)
Sorbitol or other cathartics should not be used with each dose; resulting large stool volumes may lead to dehydration or hypernatremia
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Severe intoxication: administer digoxin-specific antibodies [digoxin immune Fab (ovine) DigiFab]
Dose is estimated based on body burden of digoxin calculated from ingested dose or steady-state serum digoxin concentration
Ingested dose
Serum concentration