Anti-Arrhythmic Agents

Question 1

Answer 1

Quinidine

Class Ia agent

admin: oral

Sodium channel blocker with intermediate kinetics

Alpha blocker and blocks vagal stimulation (increase heart rate)

K+ channel blocker

ADR: Cinchonism, Diarrhea, nausea, anorexia, Torsades de pointe/ventricular arrhythmia, Thrombocytopenia, hemolytic anemia

metabolized by 3A4

2D6 inhibitor

Hepatic route of clearance

Use: A - fib, secondary agent in conversion prophylaxis, premature ventricular contractions, Wolff-parkinson, Ventricular tachycardia

Question 2

Answer 2

Lidocaine

Class Ib Agents

admin: IV

Use: PVC, VT after MI, V - fib

metabolites MEGX, GX: decreased activity, GX competes with lidocaine for binding

hepatic elimination (think of hepatic dx pt)

traditionally been utilized for the treatment of ventricular arrhythmias and premature ventricular contractions

MOA: Sodium channel blocker with fast kinetics, decreases the refractory period., suppresses automaticity in ventricular tissue, and acts preferentially in ischemic tissue.

ADR: Dizziness, sedation, slurred speech, blurred vision, numbness, Seizures, psychosis, Conduction disturbances

Question 3

Answer 3

Flecainide acetate

Class Ic agent

admin: orally

Metabolized by 2D6

inhibitor of 2D6

Use in conjunction with AV node blocking agent (CCB, B Blocker)

MOA: Sodium channel blocker with slow kinetics, Calcium channel blocker, K+ channel blocker (low rate of torsades)

Use: AF, PSVT, severe sustained ventricular arrhythmia

ADR: Dizzy, SOB, blurry vision, nausea, conduction disturbances

Question 4

Answer 4

Propafenone

Class Ic agent

Use in conjuction with AV node blocking agent

MOA: Sodium channel blocker with slow kinetics, Beta blocker, K+ channel blocker in ventricular tissue

ADR: Dizziness, fatigue, bronchspasm, taste disturbances, Nausea, vomiting, Bradycardia, Conduction disturbances

metabolized by 2D6, 1A2

Question 5

Answer 5

Amiodarone

MOA: K+ channel blocker-markedly prolongs the action potential, Beta bocker, Na+ channel blocker, Ca channel blocker (slows AV node conduction)

ADR: Tremor, ataxia, insomnia, numbness, Corneal microdeposits, pulmonary fibrosis, hepatitis, Bradycardia, hypotension, Hypothyroidism, Photosensitivity, skin discoloration, phlebitis, Constipation

Metabolized by 3A4, 2C9

p-gp inhibitor

DDI: CYP, agents that increase QT interval

half life 5 - 100 days

Question 6

Answer 6

Dronedarone

just like amiodarone, but less lipophiic

metabolized by 3A4

inhibitor of 3A4 and 2D6 and p-gp

contraindications: HF, permanent AF pt

Use: A-fib, A-flutter

ADR: Prolonged QT,

Abdominal Pain,

Nausea/Vomiting,

Bradycardia,

Hepatic injury,

Interstitial lung disease

Question 7

Answer 7

Dofetilide

Specific K channel blocker

ADR: HA, dizzy, torsades

Use: A - fib, A - flutter

admin: oral

undergoes some 3A4

Question 8

Answer 8

Ibutilide

Activates late inward sodium channel current which prolongs the effective refractory period

Opposite of ranolazine: not anti arrhythmic, but has negative inotropic effect which dec Ca2+ and treats ischemia

ADR: HA, hypotension, torsades (6%)

admin: infusion

Used to terminate A fib/flutter

Question 9

Answer 9

Sotalol

MOA: K channel blocker (delayed rectifyer) and Beta Block (will slow AV node conduction)

use: AF, PSVT, ventricular arrhythmia

ADR: dizzy, weak, fatigue, N/V, bronchospasm, aggrevation of HF, torsades