Drugs for arrhythmias
This presentation is the property of its rightful owner.
Sponsored Links
1 / 70

Drugs for Arrhythmias PowerPoint PPT Presentation


  • 157 Views
  • Uploaded on
  • Presentation posted in: General

Drugs for Arrhythmias. A. Pathophysiology of arrhythmias. Arrhythmias are a group of conditions in which the muscle contraction of the heart is irregular, and they occur in both healthy and diseased hearts. .

Download Presentation

Drugs for Arrhythmias

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Drugs for arrhythmias

Drugs for Arrhythmias


A pathophysiology of arrhythmias

A. Pathophysiology of arrhythmias

  • Arrhythmias are a group of conditions in which the muscle contraction of the heart is irregular, and they occur in both healthy and diseased hearts.


Drugs for arrhythmias

  • Many arrhythmias are associated with other cardiovascular conditions: CAD, HT, and MI.


B arrhythmia therapy

B. Arrhythmia therapy

  • Antiarrhythmic drugs do not cure the underlying causes of an arrhythmia. Instead, they attempt to restore the normal cardiac rhythm.


Drugs for arrhythmias

  • Drugs are classified according to the phase of the action potential that they affect.


1 class i antiarrhythmic drugs na 1 channel blockers

1. Class I antiarrhythmic drugs (Na1+ channel blockers)

  • This class of drugs reduces the excitability of the heart by slowing the spread of impulse conduction across the heart.


Drugs for arrhythmias

  • Sodium channel blockers are similar in structure and action to the local anesthetics.

  • This is the largest class of antiarrhythmic drugs.


Drugs for arrhythmias

  • They are subclassified according to the effects they have on the cardiac action potential.


Drugs for arrhythmias

Phase 4: The resting membrane potential, when the cell is not being stimulated (represented by baseline on the ECG).


Drugs for arrhythmias

Phase 0: This is the rapid depolarization phase and occurs with the opening of the Na1+ channels and the rapid influx of Na1+ into the cell.


Drugs for arrhythmias

Phase 1: This phase of the action potential occurs with the closure of the Na1+ channels. There is a transient net outward current due to the movement of K1+ and Cl1- ions. Phase 0 and 1 together correspond to the QRS complex of the ECG.


Drugs for arrhythmias

Phase 2: This is the plateau phase of the action potential and occurs because of the balanced inward movement of Ca2+ ions through calcium channels, and outward movement of K1+ ions through potassium channels. It corresponds to the ST segment of the ECG.


Drugs for arrhythmias

Phase 3: In this phase of the action potential, the K1+ channel is still open, allowing more K1+ to leave the cell, resulting in a net loss of positive charge, which causes the cell to repolarize. Phase 3 corresponds to the T wave of the ECG.


Drugs for arrhythmias

a. Class IAThey slow the rate of rise of phase 0 and lengthen the action potential and are indicated for managing a variety of atrial and ventricular arrhythmias.


Drugs for arrhythmias

  • Quinidine, procainamide and disopyramide are drugs in this subclass.


Quinidine gluconate 62 quinidine

quinidine gluconate (62% quinidine):

  • Quinidine is indicated for a wide variety of both atrial and ventricular arrhythmias. The off label use of this is the treatment of malaria.


Drugs for arrhythmias

  • Dosage:

  • IV: infuse at 16 mg/min until arrhythmia is resolved;

  • PO: 325 – 650 mg every 6 hours.


Quinidine sulfate 83 quinidine

quinidine sulfate (83% quinidine):

  • Dosage: PO: 400 – 600 mg every 2 – 3 hours until arrhythmia is resolved, for supraventricular tachycardia;


Drugs for arrhythmias

  • 200 mg every 2 – 3 hours for 5 – 8 doses for atrial fibrillation


Drugs for arrhythmias

  • Quinidine is related to quinine, originally derived from the bark of the cinchona tree.


Drugs for arrhythmias

  • It’s side effects include a syndrome called "cinchonism" consisting of various sound and visual disturbances (hallucinations, ringing in the ears), salivation, GI disturbances, weakness, fatigue, rashes, headache, and confusion.


Drugs for arrhythmias

  • It can cause/aggravate Torsades de pointes (an uncommon variant of ventricular tachycardia), as can all class IA drugs


Procainamide procanbid promine pronestyl

procainamide (Procanbid, Promine, Pronestyl)

  • procainamide first approved for use in the United States in 1950, is indicated for a wide variety of both atrial and ventricular arrhythmias.


Drugs for arrhythmias

  • Dosage: IV: 100 mg every 5 minutes until arrhythmia is resolved, or 500 – 600 mg every 25 – 30 minutes followed by maintenance infusion of 2 – 6 mg/min.


Drugs for arrhythmias

  • It’s most serious adverse effects include seizures, asystole, heart block, ventricular arrhythmias and agranulocytosis.


Drugs for arrhythmias

  • It’s most common adverse effects are GI disturbances. Some individuals experience lupus-like symptoms (rash, muscle pain).


Disopyramide norpace rythmodan

disopyramide (Norpace, Rythmodan)

  • disopyramide is usually only used after quinidine and procainamide have been ruled out as possibilities. It is indicated for the treatment of ventricular tachycardia.


Drugs for arrhythmias

  • Dosage: PO: 150 mg every 6 hours, not to exceed 800 mg/day

  • Disopyramide can aggravate or precipitate severe CHF.


Drugs for arrhythmias

  • Other adverse effects associated with disopyramide include dry mouth, blurred vision, urinary retention, and constipation.


Drugs for arrhythmias

b. Class IBThey shorten the action potential and are indicated for the treatment of ventricular tachycardia and prevention of ventricular fibrillation


Drugs for arrhythmias

  • Lidocaine and mexilitine are drugs in this subclass.


Lidocaine xylocaine

lidocaine (Xylocaine)

  • lidocaine is indicated for the treatment of ventricular arrhythmias.

  • Dosage: IV: 50 – 100 mg bolus over 2 minutes, then 1 – 4 mg/min infusion


Drugs for arrhythmias

  • It’s most serious adverse effects include cardiac arrest, anaphylaxis, and seizures. It’s most common adverse effects include agitation, confusion, slurred speech, tremors and drowsiness.


Mexiletine mexitil

mexiletine (Mexitil)

  • mexiletine (Mexitil) is structurally similar to lidocaine, except it can be administered orally.


Drugs for arrhythmias

  • Mexiletine is usually the class IB agent used when there is a history of MI.


Drugs for arrhythmias

  • Dosage mexiletine:

  • PO: 400 mg loading dose, then 200 mg more in 8 hours, then 200 – 400 mg every 8 hours


Drugs for arrhythmias

c. Class ICThey have no effect on the length of the action potential, but reduce the rate of rise of phase 0. These drugs are indicated for the treatment of ventricular tachycardia and supraventricular tachycardia.


Drugs for arrhythmias

  • Flecainide and propafenone are drugs in this class


Flecainide tambocor

flecainide (Tambocor)

  • flecainide (Tambocor) is used in the treatment of supraventricular tachycardia.


Drugs for arrhythmias

  • Dosage:

  • PO: 100 mg every 12 hours, increased by 50 mg bid until arrhythmia is resolved (maximum daily dose of 400 mg).


Drugs for arrhythmias

  • It’s most serious adverse effects are CHF and arrhythmias (V-tach).

  • It’s most common adverse effects are dizziness and blurred vision.


Propafenone rythmol

propafenone (Rythmol)

  • propafenone(Rythmol) is used in the treatment of both ventricular tachycardia and supraventricular tachycardia


Drugs for arrhythmias

  • Dosage:

  • PO: 150 mg every 8 hours, may be increased up to 300 mg every 8 – 12 hours.


Drugs for arrhythmias

  • It’s most serious adverse effects are the events that it is indicated for, ventricular tachycardia and supraventricular tachycardia


Drugs for arrhythmias

  • It’s most common adverse effects include dizziness, altered taste, nausea, vomiting and constipation.


2 class ii antiarrhythmic drugs beta blockers

2. Class II antiarrhythmic drugs (beta blockers)

  • This class of drugs are the beta blockers which block the effects of catecholamines at the β receptors, thereby decreasing sympathetic activity and resulting in a decrease in the heart rate.


Drugs for arrhythmias

  • They are indicated for the treatment of atrial fibrillation and atrial flutter.

  • These class II drugs include acebutolol, esmolol, propanolol, and sotalol.


3 class iii antiarrhythmic drugs k 1 channel blockers

3. Class III antiarrhythmic drugs (K1+ channel blockers)

  • By blocking K1+ channels, these drugs lengthen the action potential (by lengthening the refractory period/resting stage).


Drugs for arrhythmias

  • This tends to decrease the frequency of arrhythmias. They are indicated for the treatment of atrial fibrillation, atrial flutter,


Drugs for arrhythmias

  • as well as V-tach, and V-fib.


Drugs for arrhythmias

  • amiodarone, dofetilide and ibutilide are drugs in this class.


Amiodarone cordarone pacerone

amiodarone (Cordarone, Pacerone)

  • amiodarone is indicated for the treatment of life threatening ventricular arrhythmias, but only when the patient is unresponsive to less toxic agents (i.e. dofetilide or ibutilide)


Drugs for arrhythmias

  • Dosage:

  • PO: 800 – 1600 mg/day in 1 – 2 doses for 1 – 3 weeks, then 600 – 800 mg/day in 1 – 2 doses for 1 month, then 400 mg/day for maintenance


Drugs for arrhythmias

  • IV: 150 mg over 10 minutes, then 360 mg over 6 hours, then 540 mg over 18 hours. Maintenance infusion of 0.5 mg/minute until PO therapy is initiated.


Drugs for arrhythmias

  • Amiodarone has a very large number of adverse effects, affecting almost every part of the body:

  • ARDS

  • pulmonary fibrosis

  • CHF

  • worsening of arrhythmias


Drugs for arrhythmias

  • inflammation of the liver

  • nausea

  • vomiting

  • constipation

  • dizziness

  • fatigue


Drugs for arrhythmias

  • thyroid dysfunction

  • photosensitivity

  • involuntary movement

  • tremors

  • bradycardia


Drugs for arrhythmias

  • hypotension

  • visual problems

  • discoloration of the skin

  • decreased libido


Dofetilide tikosyn

dofetilide (Tikosyn)

  • dofetilide (Tikosyn) is indicated for the conversion of atrial fibrillation and atrial flutter to normal sinus rhythm


Drugs for arrhythmias

  • Dosage:

  • PO: Initial dose is 500 μg bid; maintenance dose is 250 μg bid


Drugs for arrhythmias

  • It’s most serious adverse effects are ventricular arrhythmias. It’s most common adverse effects are dizziness, headache and chest pain.


Ibutilide corvert

ibutilide (Corvert)

  • ibutilideis indicated for the conversion of atrial fibrillation and atrial flutter to normal sinus rhythm, especially within 1 week of bypass surgery.


Drugs for arrhythmias

  • Dosage: 1 mg infusion, that may be repeated every 10 minute

  • Dosage after cardiac surgery: 0.5 mg infusion, may be repeated once.


Drugs for arrhythmias

  • It’s most serious adverse effects are ventricular arrhythmias. It’s most common adverse effects are headache and nausea.


4 class iv antiarrhythmic drugs

4. Class IV antiarrhythmic drugs

  • These drugs prevent the movement of calcium into myocardial cells which slows depolarization and decreases the heart rate.


Drugs for arrhythmias

  • In addition, these drugs decrease the force of myocardial contractions (they would not be recommended in patients with CHF).


Drugs for arrhythmias

  • ALL CCB’s produce vasodilation, however, only verapamil and diltiazem have direct actions on the heart.


Drugs for arrhythmias

  • These drugs are effective in treating a variety of arrhythmias including atrial flutter, atrial fibrillation and supraventricular tachycardia


Drugs for arrhythmias

  • Verapamil (Calan, Verelan, Isoptin)

  • Diltiazem (Cardizem, Dilacor, Tiazac)


Drugs for arrhythmias

  • Adverse effects include:

  • headache

  • Dizziness

  • GI disturbances

  • orthostatic hypotension


  • Login