Coingestion with Calcium Channel<unk> s, Tricyclic Antidepressants, and Antipsychotics increases mortality
Agents with membrane-stabilizing activity (e.g. sodium channel blockade) are especially lethal as they prolong QT, leading to dysrhythmias
Propranolol
Sotalol
Propranolol is particularly CNS toxic, as it is highly lipophilic and passes blood brain barrier freely, causing seizures and comatose state
At toxic levels,<unk><unk> s will inhibit both<unk> -1 and<unk> -2 activity regardless for their affinity for specific receptors at therapeutic levels
Propranolol
Sotalol
Beta-blocker toxicity
Cardiac
Clonidine toxicity
Inferior MI 
Digoxin toxicity
Sick sinus syndrome
Calcium channel blocker toxicity
Neurocardiogenic/reflex-mediated