Anti-arrhythmic Drugs Flashcards
1
Q
Class IA (Mechanism of action, Effects on: APD, ERP, HR and AV conduction)
A
- Block fast sodium channels (open or activated state), and also blocks K+ channels
- Increases APD and ERP
2
Q
Class IB (Mechanism of action, Effects on: APD, ERP, HR and AV conduction)
A
- Block sodium channels (inactivated state) in partly depolarized tissues (hypoxic and ischemic)
- Decrease APD, but increase diastole and decrease heart rate
3
Q
Class IC (Mechanism of action, Effects on: APD, ERP, HR and AV conduction)
A
- Block fast sodium channels especially His-Purkinje tissue
- No effect on APD
4
Q
Class II (Mechanism of action, Effects on: APD, ERP, HR and AV conduction)
A
- Prevent beta-receptor activation; thereby decrease cAMP
- Decrease SA and AV nodal activity
5
Q
Class III (Mechanism of action, Effects on: APD, ERP, HR and AV conduction)
A
- Block K+ channels
- Increase APD and ERP; especially in Purkinje and ventricular fibers
6
Q
Class IV (Mechanism of action, Effects on: APD, ERP, HR and AV conduction)
A
- Block slow Ca++ channels
- Decrease SA and AV nodal activity
7
Q
Quinidine
Class, Specific Mechanism of action, Specific effects
A
- Class IA
- Blocks muscarinic and alpha-adrenergic receptors
- Increase heart rate and AV conduction, vasodilation with possible reflex tachycardia
8
Q
Procainamide
Class, Specific Mechanism of action, Specific effects
A
- Class IA
- Blocks muscarinic receptors (but less than quinidine)
- Slight increase in heart rate and AV conduction
9
Q
Disopyramide
Class, Specific Mechanism of action, Specific effects
A
- Class IA
- Blocks muscarinic receptors
- Increase heart rate and AV conduction; also -ve inotropic effect that significantly decreases contractility
10
Q
Ajmaline
Class, Specific Mechanism of action, Specific effects
A
- Class IA
- None
- None
11
Q
Lidocaine
Class, Specific Mechanism of action, Specific effects
A
- Class IB
- None
- None
12
Q
Phenytoin
Class, Specific Mechanism of action, Specific effects
A
- Class IB
- None
- None
13
Q
Mexiletine
Class, Specific Mechanism of action, Specific effects
A
- Class IB
- None
- None
14
Q
Tocainide
Class, Specific Mechanism of action, Specific effects
A
- Class IB
15
Q
Flecainide
Class, Specific Mechanism of action, Specific effects
A
- Class IC
- Inhibits ryanodine receptor 2 (RyR2); a major regulator of sarcoplasmic release of stored Ca++
- Negative inotropic effect
16
Q
Propafenone
Class, Specific Mechanism of action, Specific effects
A
- Class IC
- Blocks beta-adrenergic receptors
- Decrease heart rate
17
Q
Amiodarone
Class, Specific Mechanism of action, Specific effects
A
- Class III
- Blocks fast sodium, Ca++, K+ channels, and beta-adrenergic receptors
- Increase APD and ERP in all cadiac tissue
18
Q
Sotalol
Class, Specific Mechanism of action, Specific effects
A
- Class III
- Non-selective beta blocker
- Decrease heart rate and AV conduction
19
Q
Ibutilide
Class, Specific Mechanism of action, Specific effects
A
- Class III
- Activation of specific slow sodium channels leading to inward sodium current
- Increase APD and ERP by that mechanism
20
Q
Verapamil
Class, Specific Mechanism of action, Specific effects
A
- Class IV
- Non
- None
21
Q
Diltiazem
Class, Specific Mechanism of action, Specific effects
A
- Class IV
- None
- None
22
Q
Adenosine
Class, Specific Mechanism of action, Specific effects
A
- Unclassified
- Activates adenosine receptors (Gi-coupled) which leads to decrease cAMP causing increased K+ efflux and hyperpolarization (transient asystole)
- Decrease SA and AV nodal activity
23
Q
Magnesium sulfate (Class, Specific Mechanism of action, Specific effects)
A
- Unclassified
- None
- None
24
Q
Quinidine
Clinical Uses
A
Many arrhythmias especially in AF
25
Procainamide
| Clinical Uses
Life-threatening arrhythmias
26
Disopyramide
| Clinical Uses
Ventricular tachycardia
27
Ajmaline
| Clinical Uses
- Diagnosis of Brugada syndrome
- Treatment of WPW
- Ventricular tachycardia
28
Lidocaine
| Clinical Uses
- Post-MI arrhythmias
- Open heart surgery arrhythmias
- Digoxin toxicity
- Local anesthetic
29
Phenytoin
| Clinical Uses
- Seizures
- Status epilepticus (second-line)
- Trigeminal neuralgia (second-line)
- Digoxin toxicity
- Ventricular tachycardia (after all others have failed)
30
Mexiletine
| Clinical Uses
- Post-MI arrhythmias
- Open heart surgery arrhythmias
- Digoxin toxicity
- Back-up for ventricular tachycardia
31
Flecainide
| Clinical Uses
Supraventricular tachycardias including AVNRT and WPW
32
Amiodarone
| Clinical Uses
Any type of arrhythmia
33
Sotalol
| Clinical Uses
Life-threatening ventricular arrhythmias
34
Ibutilide
| Clinical Uses
Acute cardioversion in AF and atrial flutter of a recent onset to sinus rhythm
35
Verapamil
| Clinical Uses
Supraventricular tachycardias
36
Diltiazem
| Clinical Uses
Supraventricular tachycardias
37
Adenosine
| Clinical Uses
- Paroxysmal supraventricular tachycardias (drug of choice)
| - AV nodal arrhythmias
38
Magnesium sulfate
| Clinical Uses
Torsade de pointes
39
Quinidine
| Adverse Effects
- Cinchonism (GI upset, tinnitus, ocular dysfunction, and CNS excitation)
- Hypotension
- Increase QRS and QT interval (Torsade)
- Hyperkalemia increases its toxicity; and it increases toxicity of digoxin (by displacing it from binding sites)
- Increase mortality due to tachycardia
40
Procainamide
| Adverse Effects
- SLE like syndrome (30%) which is more likely in slow acetylators (metabolized to NAPA)
- Hematotoxicity (thrombocytopenia and agranulocytosis)
- CNS: dizziness and hallucinations
- Cardiovascular: torsade de pointes
41
Disopyramide
| Adverse Effects
- Anti-cholinegic effects
| - Agranulocytosis
42
Lidocaine
| Adverse Effects
- Seizures
| - Least cardiotoxic of all conventional anti-arrhythmics
43
Flecainide
| Adverse Effects
Contra-indicated in post-MI patients and patients with structural heart abnormalities because it causes sudden cardiac death
44
Amiodarone
| Adverse Effects
- Pulmonary fibrosis
- Blue pigmentation of skin ("smurf skin")
- Phototoxicity
- Corneal deposits
- Hepatic necrosis
- Thyroid dysfunction
45
Sotalol
| Adverse Effects
Torsade de pointes
46
Ibutilide
| Adverse Effects
Torsade de pointes
47
Verapamil
| Adverse Effects
- Constipation
- Dizziness and nausea
- Hypotension
- Headache
- AV block (additive with beta-blockers and digoxin)
- Gingival hyperplasia
- Increases digoxin toxicity (by displacing it from binding sites)
48
Diltiazem
| Adverse Effects
- Flushing
- Hypotension and bradycardia
- Dizziness
- AV block (additive with beta-blockers and digoxin)
49
Adenosine
| Adverse Effects
- Flushing
- Dyspnea
- Sedation
- Antagonized by theophylline and caffeine
50
Effects of increased cAMP on Action potential
- Increase upstroke velocity in pacemakers by increase of I-Ca-L
- Shorten APD by increase of I-K
- Increase heart rate by increase of I-f, thus increasing slope of phase 4
51
Effects of decreased cAMP on Action potential
- Decrease upstroke velocity in pacemakers by decrease of I-Ca-L
- Prolong APD by decrease of I-K
- Decrease heart rate by decrease of I-f and produces K+ current (I-K/ACh) which slows rate of diastolic depolarization
