Arrhythmia drugs

Question 1

Lidocaine

Sodium channel blocker

Answer 1

For Ventricular Tachycardia but rarely used

Blocks sodium channels in depolarized cells, in the inactive state

Question 2

Metoprolol

Cardioselective beta blocker

Answer 2

Controls heart rate in atrial fibrillation/ AV block

Contraindications : unstable HF, bronchospasm asthma and PVD

Question 3

Amiodarone

Pottasium channel blocker and other actions

Answer 3

• Prolongs most EP intervals. Increases refractory period - cardiac hyperpolarization prevention
• Termination VT/AF
• Increases digoxin and warfarin levels
• Lung and liver toxicity,
• TFT changes

Question 4

CCB : non-dihydropyridines

Role in arrhythmic action

Answer 4

Slows ventricular in AF, hyptension, AV block with digoxin or beta-blockers, negative ionotrope, worsens HF

Question 5

Adenosine

Answer 5

• Inhibits AV nodal conduction to post systolic tachycardia
• Slows heart rate to facilitate arrhythmia diagnosis
• asystole
• asthma
• flushing

Question 6

Digoxin

Na,K,ATP inhibitor

Answer 6

• Ventricular rate control in atrial fibrillation
• Slows AV conduction
• Little effect on rate during exercise
• Common adverse effects
• Used in HF
• Antibody for sever toxicity
• Cognitive dysfunction