Final answer:
Amiodarone mechanism involves blocking multiple ion channels and prolonging the action potential of heart cells, aiding its antiarrhythmic effects. Side effects can include pulmonary, thyroid, liver toxicity, vision issues, and skin changes, with risks increased by factors such as high doses and long-term use. Contraindications include hypersensitivity, severe sinus-node dysfunction, and certain cardiac conduction issues without a pacemaker.
Step-by-step explanation:
Amiodarone is an antiarrhythmic medication primarily used to treat and prevent various types of cardiac dysrhythmias, such as ventricular tachycardia and ventricular fibrillation.
Mechanism
The mechanism of action of amiodarone includes prolongation of the myocardial cell action potential duration and refractory period, as well as inhibitory effects on several cardiac ion channels, including sodium, potassium, and calcium channels, contributing to its antiarrhythmic properties.
Side Effects + RF
Common side effects of amiodarone include pulmonary toxicity, thyroid disease (either hypo- or hyperthyroidism), liver toxicity, ocular deposits leading to visual disturbances, and skin discoloration. Risk factors (RF) for experiencing side effects may include high cumulative doses, long-term use, and pre-existing organ dysfunction.
Contraindications
Amiodarone has several contraindications, which include hypersensitivity to the drug or its components, severe sinus-node dysfunction, second- or third-degree atrioventricular (AV) block without a pacemaker, and cases of bradycardia leading to syncope without a pacemaker.