Figure 15 Structure of amiodarone.

38 Amiodarone Amiodarone

Amiodarone (Figure 15) is the only antiarrhythmic that, to a limited degree, reduces the incidence of cardiac arrhythmic sudden death, although with less efficacy than implanted defibrillators.21

• Mechanism: The mechanism of action of amiodarone is complex. Although originally classed as one of the prototype class 3 antiarrhythmic drugs that widen action potentials, it has since been found to block other channels, and even ^-adrenoceptors. The importance of these latter effects is unknown.

• Effectiveness: Amiodarone reduces mortality due to ventricular tachyarrhythmias, and has value in the prophylaxis of atrial arrhythmias. It can be given both intravenously and orally.

• Toxicity: Amiodarone produces toxicity in the lungs, increases skin sensitivity to ultraviolet radiation, and induces corneal opacities in the eye. The toxicity in the lungs can be fatal. The drug has very unusual pharmacokinetics with a long half-life (days to weeks), but if given carefully, serious major toxicity can be avoided.

Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

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