Overdose of these drugs is chronic and is almost always due to careless treatment. The reactions can be seen as an exaggerated expression of their pharmacological properties. Once toxic levels are reached, the subject experiences mental confusion, vomiting, diarrhea and visual disturbances. Subsequently, bradycardia and overlapping arrhythmias occur, which may result in tachyarrhythmias.
Diagnosis and treatment
History and clinical signs are sufficient to make the diagnosis, but at least for digoxin it must be with measurement of plasma levels. Within 18 to 20 hours after acute ingestion, the stomach should be emptied by inducing vomiting, immediately after which a dose of activated charcoal (100gr for an adult, 25 for a child) can be given. IV potassium can be administered for hypokalemia. For individuals with heart disease and those showing atrioventricular blockade, an intravenous pacemaker may be necessary.
Source: Vadecum of poisoning therapy by Roy Goulding
