Essay

Question 1

بسم الله الرحمن الرحيم وبه نستعين
توكلنا علي الحي الذي لايموت سبحان الله وبحمده
Classify antiarrhythmic drugs according to mechanism of action. Mention one
example for each group

Answer 1

Class I: Na+channel blockers
Ia: Procainamide Ib: Lidocaine, Phenytoin Ic: Propafenone

Class II: beta blockers: Propranolol, Esmolol, Atenolol

Class III: K+channel blockers: Amiodarone

Class IV: CCBs: Verapamil

Miscellaneous: Adenosine, Digoxin

Question 2

List 3 antiarrhythmic drugs acting by blocking of sodium channels. Enumerate
adverse effect of one of them ( Page 6, 7)

Answer 2

Class I: Na+
channel blockers
Ia: Procainamide Ib: Lidocaine, Phenytoin Ic: Propafenone

1. Cardiac toxicity
   a. Hypotension: (Ganglion blocker) & Myocardial depression (-ve inotropic)
   b. Block K+channels → ↑ APD → prolong QT interval → polymorphic ventricular tachycardia (Torsade de pointes) → Syncope
   c. ↓ AVN conduction. BUT In AF → Paradoxical ↑ in AVN conduction may occur due to its atropine like action ؟ ايه الحل
2. Thromboembolism: Chronic AF → thrombus → emboli on return to sinus rhythm by drugs. Add heparin
3. Special adverse effects: Procainamide: Lupus like syndrome in slow acetylator. Quinidine: Thrombocytopenia & cinchonism
   Disopyramide: Heart failure, Urine retention & glaucoma

Question 3

Enumerate 4 adverse effects of class Ia antiarrhythmic drugs (Procainamide) P6

Answer 3

cardiac toxicity hypotension block K channels decrasing AVN conduction

git ypse
Thromboembolism
Special Priacnimed SLE 
Qunidine proled qt interval '
In disopyramide : -  Heart failure urein reterntion

Question 4

Theraputic uses of Lidocaine >?

Answer 4

Ventricular arrhytmia

Ventriciulart Tachycardia due to Cardiac surgery or myocardial infarction ischemia

Digitalis induced arrhyhmia

Question 5

Adverse effects of proafenone?

Answer 5

Cardiac: Heaert failure ,heat block ,
Taste disturbances blurring of vision
BB EFFECTS: Bronchospasm ,Constipation