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z MECHANISM OF TOXICITY (Part 1) Pharmaceutical Toxicology Laboratory
z AMIODARONE ▪ Mechanism of Toxicity: ▪ In addition to its predominant Vaughan- Williams class III effects, amiodarone also has class I, II and IV properties.
z AMIODARONE ▪ Mechanism of Toxicity: ▪ Its principal class III effects are secondary to blockade of potassium channels, which prolong phase 4 of the cardiac action potential and the refractory period of atrial and ventricular tissue.
z AMIODARONE ▪ Clinical Manifestations: ▪ Patients are usually asymptomatic, but delayed onset (more than 24 hours) of bradycardia, hypotension and self-limiting atrial and ventricular tachyarrhythmias has been reported.