Anti-arrhythmics

Question 1

Give examples of class Ia drugs?

Answer 1

Quinidine
Procainamide
Disopyramide

Question 2

MOA of Ia?

Answer 2

Block sodium channels

Increases AP duration

Question 3

Give examples of class Ib?

Answer 3

Lidocaine
Mexiletine
Tocainide

Question 4

MOA of Ib?

Answer 4

Block sodium channels

Decreases AP duration

Question 5

Examples of Ic?

Answer 5

Flecainide
Encainide
Propafenone

Question 6

MOA of Ic?

Answer 6

Block sodium channels

No effect on AP duration

Question 7

Examples of class II?

Answer 7

Propranolol
Atenolol
Bisoprolol
Metoprolol

Question 8

MOA of class II?

Answer 8

Beta-adrenoceptor antagonists

Question 9

Examples of class III?

Answer 9

Amiodarone
Sotalol
Ibutilide
Bretylium

Question 10

MOA of class III?

Answer 10

Block potassium channels

Question 11

Examples of class IV?

Answer 11

Verapamil
Diltiazem

Question 12

MOA of class IV?

Answer 12

Calcium channel blockers

Question 13

MOA of adenosine ?

Answer 13

causes transient heart block in the AV node
agonist of the A1 receptor in the atrioventricular node, which inhibits adenylyl cyclase thus reducing cAMP and causing hyperpolarization by increasing outward potassium flux
adenosine has a very short half-life of about 8-10 seconds

Question 14

S/E of adenosine?

Answer 14

chest pain
bronchospasm
transient flushing
can enhance conduction down accessory pathways, resulting in increased ventricular rate (e.g. WPW syndrome)

Question 15

Atropine use?

Answer 15

Atropine is an antagonist of the muscarinic acetylcholine receptor.

Uses
symptomatic bradycardia
IV atropine is the first-line treatment for bradycardia with adverse signs
treatment of organophosphate poisoning

Question 16

Physiological effects of atropine?

Answer 16

Physiological effects
tachycardia
mydriasis
atropine may trigger acute angle-closure glaucoma in susceptible patients