Antiarrhythmic Drugs Flashcards
What is arrhythmias
Arrhythmias is a problem of rate or rhythm of the heartbeat as a result of electrical impulses generation and conduction
Causes of arrhythmias
*drugs(antiarrythmic drugs)
*electrolyte imbalance
*smoking
*intoxications
*Thyrotoxicosis
Mechanism of arrhythmias
*Abnormal disorders of electrical conduction
*disorder of impulse generation and conduction
Classification of anti-arrhythmias drugs
*class 1A (sodium channel blockers)
-quinidine
-procainamide
-disopyramide
*class 1B
-Lidocaine
-mexiletine
*class 1c
-flecainide
-propafenone
Class II( Beta blockers)
-propranolol
-Bisoprolol
Class III (potassium channel blockers)
-Amiodarone
-Sotalol
Class IV (calcium channel blockers)
-Verapamil
-Diltiazem
Which method of proarrhythmic effects of antiarrhythmic drugs
Noninvasive methods
*ECG monitoring
*24 hour hooter monitoring
*Exercise stress tests
Invasive methods
* Electrophysiology study of heart (cardiac stimulation induce arrhythmias)
Indications of class 1A
*supraventricular arrhythmias
- paroxysmal Av nodal tachycardia
-Atrial fibrillation and flutter in patients
* ventricular arrhythmias
- ventricular extrasytole
Side effects of quinidine
- haemolytic anaemia
*thrombocytopenia
*quininism
*idioventricular rhythms
Contraindications quinidine
*Torsade de pointes
*Av block ,his bundle branch block
* myasthenia
*myocarditis
Sides of procainamide
*lupus like syndrome
*Agranulocytosis
*Arterial hypotonia
Contraindications of procainamide
*systemic lupus erythematosis
*Torsade de pointes in past medical
*Av block II-III degree
Which kind of arrhythmias does class 1B (lidocaine,flecainide)
Ventricular arrhythmias
Indications of class 1 C sodium channel blockage
*Effective for the treatment of both atrial and ventricular arrhythmias
* it’s a rescue medications because they increase the risk of death in patients
Indications of flecainide
*Drug of choice for atrioventricular (AV)re-entrant tachycardia
*Paroxysmal atrial fibrillation
Contraindications of flecainide
*Atrioventricular block II-III grade
*Sick sinus syndrome
*hemifascicular block
Propafenone indication
*suppress non-sustained ventricular arrhythmias
Contraindications of propafenone
*cardiogenic shock,severe chronic heart failure
*atrioventricular block II-III
*severe electrolyte disturbances
*myasthenia
*sick sinus syndrome
Beta blockers indication for arrhythmias
Both supraventricular arrhythmias and ventricular arrhythmias
Prophylaxis of cardiac arrhythmias
Commonly used beta blockers in arrthymias
- Esmolol
*sotalol
Class III ( potassium channel blockers) drug and indication
Amiodarone
*indication -they are used both supraventricular arrhythmias and ventricular arrhythmias
Which drug is the most powerful drug for treatment and prevention of both atrial and ventricular arrhythmias
Amiodarone
Side effects of Amiodarone
- Qt prolongation
*bradycardia
*ventricular arrhythmias
*pulmonary fibrosis
Interaction of Amiodarone and digoxin and warfarin
Increases the plasma level of Amiodarone,digoxin and warfarin leading to bleeding and digoxin toxicity
Class IV (calcium channel blockade)
*verapamil
*diltiazem
Adenosine have which half life
Less than 10 seconds
Adenosine is used for treatment
*Terminating paroxysmal supraventricular (re-entrant) tachycardias,including episodes
Contraindications of adenosine
*adenosine should not be given to asthmatics
*2-3 Av block or sick sinus syndrome (unless a pacemaker is in place)
