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24 Cards in this Set
- Front
- Back
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What is the name of the classification of antiarrhythmic drugs? |
The Vaughan Williams classification. |
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How are drugs classified in the Vaughan Williams classification, and what is the mechanism of action for each class? |
Class I(a, b, c) - Na channel blockers Class II - beta blockers Class III - K channel blockers Class IV - Ca channel blockers |
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What are the subtypes of class I antiarrhythmics, and what's the difference between them? |
Class Ia - intermediate strength Na channel blockers Class Ib - strong Na channel blockers Class Ic - weak Na channel blockers |
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Which class Ia drugs are important? |
Disopyramide |
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Which class Ib drugs are important? |
Lidocaine (IV) and mexiletine (oral) |
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Which class Ic drugs are important? |
Flecainide |
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Which class II drugs are important? |
Beta blockers like metoprolol, atenolol, esmolol, etc .. |
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Which class III drugs are important? |
Amiodarone and dronedarone |
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Which class IV drugs are important? |
Verapamil and diltiazem |
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Which antiarrhythmics are not classified according to the Vaughan Williams classification, but are still important? |
Adenosine, magnesium sulphate and vernakalant |
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What is the main disadvantage of most antiarrhythmics, that limits their clinical use? |
They're also pro-arryhthmic |
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Which drugs are included in class Ia and what are their indications? |
Disopyramide. Used in supraventricular and ventricular tachycardias. |
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Which drugs are included in class Ib and what are their indications? |
Lidocaine and mexiletine. Used in arrhythmias caused by AMI. |
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Which drugs are included in class Ic and what are their indications? |
Flecainide. Used to prevent paroxysmal atrial fibrillation. |
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Which drugs are included in class II and what are their indications? |
Metoprolol, atenolol, esmolol, etc. Used to prevent ventricular fibrillation and sudden cardiac death after AMI. |
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Which drugs are included in class III and what are their indications?
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Amiodarone and dronedarone. Used in supraventricular and ventricular arrhythmias. |
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What are the important side effects of amiodarone and dronedarone? |
- Corneal deposits - Photosensitivity of the skin - Thyroid dysfunction (in amiodarone) - Pulmonary fibrosis |
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Which drugs are included in class IV and what are their indications? |
Verapamil and diltiazem. Used in paroxysmal supraventricular tachycardia, atrial fibrillation and atrial flutter. |
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What are the indications for adenosine? |
Adenosine is used to terminate paroxysmal supraventricular tachycardia. |
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What are the indications for magnesium sulphate? |
Magnesium sulphate is used to terminate torsade de pointes. |
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What are the indications for vernakalant? |
Vernakalant is used to convert atrial fibrillation to sinus rhythm. |
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What is the mechanism of action of adenosine? |
Adenosine binds to A1 adenosine receptors and induce a negative dromotropic effect. |
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What is the mechanism of action of vernakalant? |
Vernakalant blocks multiple ion channels in the atrial myocardium. |
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How are the pharmacokinetics of amiodarone? |
It's very lipophilic, so it accumulates in tissues and has a half-life of 1 month. |
