CV130 Antiarrhythmic Drugs Flashcards
What are the adverse effects of quinine?
1) cinchonism - CNS toxicity including tinnitus, confusion, hearing loss, visual disturbances
2) QT prolongation
What is the effect of Quindine?
1) class 1 A drug
2) has anticholingeric effect that can increase AV nodal conduction
What are the effects of procainamide?
1) Class 1A drug
2) Less anticholinergic effect than quinidine
What is the drug of choice out of the Class 1A’s?
Procainamide because it can also be given through IV
What are the adverse effects of procainamide?
1) myocardial depressant at high doses
2) lupus-like syndrome
3) QT prolongation
What is the effect of quinidine?
1) more anticholinergic than quinidine
2) strong myocardial depressant
When is disopyramide used?
rarely used. Used when need negative inoptropy
What are the adverse effects of disopyramide?
1) anticholinergic effects - constipation, urinary retention, glaucoma worsening
2) QT prolongation & associated arrhythmias
When are class 1B drugs used?
- acts on diseased and ischemic tissues, especially in ventricular tissues
- reserved for ventricular tachyarrhythmias
How are class 1B adverse effects different from class 1B?
Class 1B does not prolong the QT
In what situation is lidocaine used?
for people with weak hearts because it causes little myocardial depression
How is lidocaine administered?
IV
What makes lidocaine unique?
it is very specific for ventricular tissues, especially in ischemic areas
What is the structurally similar congener of lidocaine that comes in pill form?
mexiletine
What are the adverse effects of lidocaine?
CNS toxicity - dose-related dizziness, parenthesis, confusion, delirium, coma, seizures
In what types of patients should class IC drugs be avoided?
in patients with structural heart disease
How does Flecainide work?
- reduces conduction velocity in all tissues without any significant increase in QT.
- can depress ventricular function
what are the adverse effects of flecainide?
1) CNS toxicity
2) myocardial depression
3) proarrhythmia
What are the adverse effects of propafenone?
1) CNS toxicity
2) myocardial depression
3) proarrhythmia
- same as flecainide
Explain beta-blockers and their association with ischemia
They can improve ischema which may also indirectly reduce schema-induced arrhythmias
How do beta-blockers help supra ventricular tachycardias?
1) if arrhythmia is self-sustaining in the atria - slows down ventricular rate
2) if the arrhythmia needs the AV node for re-entry - may stop the arrhythmia
What are adverse effects of beta blockers
1) may cause hypotension and bradycardia
2) may worsen asthma
which drug has the most versatile use, and has effects that fall in all classes?
amiodarone
what are the advantages of using dronedarone over amiodarone?
even though it is less efficacious, there is less thyroid, pulmonary and liver toxicity associated with this drug
What are the adverse effects of dronedarone?
1) GI intolerance
2) increased mortality
when is sotalol used?
for supraventricular and ventricular arrhythmias
What are the adverse effects of sotalol?
1) proarrhythmia
2) similar profile to beta blockers
How does sotalol work?
since it is a racemic mixture, it blocks K channels but also is a beta blockade
What are the predominant effects of verapamil and diltiazem?
slowing of AV node
How does adenosine work?
1) works at adenosine receptors which results in activation of K channels. This slows SA node and Av node conduction
2) inhibits adenylate cyclase –> decreased cAMP –> reduction in If and Ca channels
What are the adverse effects of adenosine?
transient but severe flushing, chest pain and shortness of breath
Which drugs are used to slow AV node conduction?
1) CCBs
2) beta blockers
3) adenosine
What drugs are used to suppress atrial arrhythmias?
1) class 1A
2) class 1C
3) beta blockers
4) class III
What drugs are used to suppress ventricular arrhythmias?
1) Class 1 (A,B,C)
2) Beta blockers
3) Class III
4) sometimes CCBs
