Table 7

Specific antiarrhythmic drugs used in poisoning; drugs to avoid are also shown

ToxinFirst line antiarrhythmic agentsOther antiarrhythmic agentsAntiarrhythmic agents to avoid
Ensure adequate resuscitation and supportive treatment. Arrhythmias may be relatively benign in healthy children and drug therapy should be avoided wherever possible.
AntihistaminesSodium bicarbonateMagnesium sulphateClass Ia and III27
Antihistamines terfenadine or astemizoleSodium bicarbonatePropanolol, isoprenaline, flecainide27, magnesium sulphateClass Ia and III
Class I antiarrhythmics, e.g. Ia quinidine and procainamide, Ib lignocaine, Ic flecainideSodium bicarbonate, run mildly alkalotic and keep potassium low normal33Atropine, phenytoin33Class I (although lignocaine can be used for arrhythmias due to Ia and Ic)33
Class II antiarrhythmics, i.e. β blockersAtropine, glucagon, cardiac pacing27Adrenaline, isoprenaline, dopamine, dobutamine34
Class III antiarrhythmics, i.e. sotalol and amiodaroneAmiodarone—toxicity is generally low Sotalol—initial treatment as for other β blockersLignocaine—for sotalol,27 magnesium sulphate34Isoprenaline can result in tachyarrhythmias27
Class IV antiarrhythmics, i.e. calcium channel antagonistsCalcium gluconate,33,34 cardiac pacingAtropine, glucagon, dopamine
CocaineSodium bicarbonate35Diazepam, GTN, calcium antagonists36–38
DextropropoxypheneNaloxone,39 sodium bicarbonate40Magnesium sulphate, phenytoin, atenolol27,41Class I, atropine27
DigoxinCorrect hyperkalaemia (avoid calcium), digoxin antibodies , cardiac pacingAtropine, lignocaine, amiodarone, phenytoin27Class Ia, Ic,29 DC shock,29 calcium, inotropes
QuinineKeep potassium low normalPhenytoin, β blockers, glucagon27Class Ia27 Lignocaine may precipitate convulsions27
TheophyllineAvoid treatment if at all possible—2nd line agents may cause bronchoconstrictionPropanolol,42 esmolol, adenosine27—all may produce bronchoconstriction in asthmaticsVerapamil, lignocaine42
Tricyclic antidepressantsSodium bicarbonate, try to avoid other agents as much as possiblePhenytoin, atenolol,27 glucagon,43 lignocaine for ventricular arrhythmias, magnesium sulphateClass Ia27