Arrhythmias

Question 1

Key drugs that can increase or prolong the QT Interval (26 drugs)

Answer 1

Antiarrhythmics (Class Ia, Ic, and III)
Antimalarials (hydroxychloroquine)
Azole antifungals
Macrolides
Quinolones
Lefamulin
SSRIs (highest risk with citalopram and escitalopram)
TCAs
Mirtazapine, trazodone, venlafaxine
5-HT3 receptor antagonists
Droperidol, metoclopramide, promethazine
First gen antipsychotics
Second gen antipsychotics (highest risk with ziprasidone)
Androgen deprivation therapy (leuprolide)
Tyrosine kinase inhibitors
Arsenic trioxide
Cilostazol, donepezil, fingolimod, hydroxyzine, loperamide, methadone, ranolazine, solifenacin

Question 2

Vaughan Williams classification (antiarrhythmics classifications)

Answer 2

Class I: Sodium channel blockers
Ia: Disopyramide, Quinidine, Procainamide
Ib: Lidocaine, Mexiletine
Ic: Flecainide, propafenone
Class II: Beta-Blockers
Class III: Potassium channel blockers
Dronedarone, Dofetilide, Sotalol, Ibutilide, Amiodarone
Class IV: Non-DHP CCBs
Verapamil, Diltizem

Double Quarter Pounder, Lettuce, Mayo, Fries Please! Because Dieting During Stress Is Always Very Difficult

Question 3

Amiodarone Boxed Warnings (3)

Answer 3

Pulmonary toxicity
Hepatotoxicity
For life-threatening arrhythmias only; proarrhythmic

Question 4

Amiodarone Contraindications

Answer 4

Iodine Hypersensitivity, sick sinus syndrome, 2nd/3rd degree heart block, or bradycardia causing syncope, cardiogenic shock

Question 5

Key counseling points for amiodarone

Answer 5

Can cause:
Lung damage
Liver damage
Eye damage (nerve damage and corneal deposits)
Hypothyroidism or hyperthyroidism
Photosensitivity
Skin discoloration to a blue-gray color. Not a harmful effect; usually goes away months after the medication is stopped
Avoid grapefruit
Many drug interactions (G<3PACMAN)