Name: Tocainide (Tonocard)
Class: Antidysrhythmic Agent (Class IB)
Mechanism: Shortens phase 3 repolarization. Little change in action potential duration. Inhibits arrhythmias caused by abnormal automaticity. Rapid speed of dissociation from Na+ channels.
Absorption: Oral
Dist.:
Metabolism.:
Excretion, t½:
Toxicity/S.E.s: Proarrhythmic effects, negative inotropy, infranodal conduction block. N/v, dizziness, disorientation, tremor. Hematologic effects (agranulocytosis, bone marrow suppression, thrombocytopenia) can be fatal.
Utility: Treat ventricular tachyarrhythmias (only as a last resort).
Special Features: Concurrent use w/quinidine may be effective at lower doses than either alone ® ¯ adverse effects of each.