Car 11 - Antiarrhythmics Flashcards
What are the 4 types of antiarrhythmics?
[No Bad Boy Keeps Clean] No: Na+ channel blockers (I). Bad boy: beta blockers (II). Keeps: K+ channel blockers (III). Clean: Ca2+ channel blockers (IV).
What are class I antiarrhythmics going to do to the ventricular action potential phases?
It decreases the slope of phase 0, therefore elongating the effective refractory period.
What are three Class 1A antiarrhythmics?
[Double Quarter-Pounder] Disopyramide. Quinidine. Procainamide.
What are three Class 1B antiarrhythmics?
[Mayo, Lettuce, Tomato] Mexiletine. Lidocaine. Tocainide.
What are three Class 1C antiarrhythmics?
[Fries, Please] Flecainide, Propafenone.
What drugs do we use for Wolff-Parkinson-White (WPW)?
Procainamide (Class 1A antiarrhythmics). Amiodorone (Class III antiarrhythmic).
What are two things about Procainamide?
Used in Wolff-Parkinson-White (WPW). Can cause a reversible SLE-like syndrome.
What five drugs can cause drug-induced Lupus?
[SHIPP] Sulfonamides. Hydralazine. Isoniazid. Procainamide. Phenytoin.
What three side effects can Quinidine cause?
Cinchonism (Headache, Dizziness, Tinnitus). Thrombocytopenia. Torsades de Pointes (increase in QT interval).
What three settings do we use Lidocaine as an antiarrhythmic?
Acute ventricular tachyarrhythmias. Digitalis-induced arrhythmias. Tachyarrhythmias post-MI.
What does hyperkalemia do in the use of antiarrhythmics?
Can increase their toxicities.
What 5 beta-blockers are used as antiarrhythmics?
Propanolol. Esmolol. Metoprolol. Atenolol. Timolol.
What is the MOA of beta blockers as antiarrhythmics?
They decrease cyclic AMP and decrease calcium currents. So they increase the PR interval and suppress abnormal pacemakers by decreasing the slope of phase 4 (In the pacemaker action potential).
What are 5 side effects of beta blocker?
Exacerbation of asthma. Bradycardia. AV block. CHF exacerbation. Mask effect of hypoglycemia.
What is the treatment for beta-blocker overdose?
Glucagon.
What are class III antiarrhythmics going to do to the ventricular action potential phases?
Work on phase 3. It slows down the release of potassium, thereby elongating the effective refractory period, increasing action potential duration, and the QT interval.
What are five class III antiarrhythmic drugs?
Amiodarone. Ibutilide. Sotalol. Bretylium. Dofetilide.
What are three potential side effects of Amiodarone?
Pulmonary fibrosis. Hepatotoxicity. Hypo- or hyperthyroidism (Amiodarone is 40% iodine by weight). [When using amiodorone, use your PFTs, LFTs, and TFTs.] Can also cause corneal deposits, and skin (blue-grey) depositis (photodermatitits). Can also cause neurologic effects, constipation, CV (bradycardia, heart block, heart failure).
What three drugs cause photosensitivity?
[SAT for photo] Sulfonamides. Amiodarone. Tetracycline.
What are the 2 subclasses of class 4 antiarrhythmic drugs (Ca2+ channel blockers)?
Non-dihydropyridine (work on the heart): Verapamil, Diltiazem. Dihydropyridine (work at the periphery): Nifedipine, Felodipine, Amlodipine.
How do non-dihydropyridine Ca2+ channel blockers work as antiarrhythmics?
They decrease the slope of phase 0 of the ventricular action potential, elongating effective refractory period. There is a decrease in conduction velocity in AV nodes as well.
What are four side effects of Ca2+ channel blockers?
Constipation. Flushing. Edema. CV (heart failure, AV block, Sinus node depression, Torsades de Pointes).
How does Adenosine work as an antiarryhthmic?
Increases the K+ leaving the cell, hyperpolarizing the cell. Decreases the permeability of Ca2+ as well (decreases intracellular Ca2+).
When do we use adenosine as antiarrhythmic?
Supraventricular tachycardia(SVT) (can help both diagnose it and treat it).
What are the side effects of Adenosine?
Flushing. Hypotension. Angina.
How do we block the effects of Adenosine?
Theophylline.
What levels should K+/Mg+ be, especially for post-MI patients?
K+: Above 4. Mg+: above 2. Because they are predisposed to arrythmias.
Which antiarrhythmic has the side effect of cinchonism?
Quinidine.
