Antiarrhythic Therapy Flashcards
Anti-arrhythmic agents
1a) quinidine, procainamide, disopyramide
1b) mexilitene, didocaine
1c) flecainide, propafenone
III) sotalol, dofetilide, dronedarone, ibutilide (channel blockers)
- amiodarone, ranolazine
Ia - Quinidine
- stereo isomer of quinine, derived from cinchona tree
- blocks fast inward Na+ channel: use dependent=more block w/ faster heart rate, prolongs action potential duration & QT interval (not good)
Ia - Quinidine: reason for decreased usage
- used for Afib & ventricle tachycardia till 1990s
- caused diarrhea, thrombocytopenia, hepatitis, TORSADES DE POINTES due to QT prolongation
Ia - Quinidine: new uses
- brugada syndrome & early repolarization syndrome
Ia - Quinidine: metabolism
- live metabolism: cytochrome p450
Ia - procainamide
- uses: Afib, Wolff-Parkinson White Syndrome, VT “Storm”
- sodium channel blocker but also blocks outward potassium channels
- can cause rashes myalgias, lupus
- Renal Metabolism
Ia - Disopyramide
- sodium channel blocker
- VAGOLYTIC: speeds up heart, UNLIKE other channel blockers
- uses: Afib especially in HCM
- anticholinergic side effects: dry mouth, blurred vision, constipation, urinary retention (used less in older men)
- Renal Excretion
Ib - Lidocaine
- ONLY IV
- NARROW therapeutic range
- useful as adjunct to amiodarone or sotalol in ventricular arrhythmias
- shortens QT
- LIVER metabolized
Ib - Mexilitene
- good agent to use w/ amiodarone or sotalol (transition from lidocaine)
- shortens QT
- pretty much ORAL form of lidocaine
- uses: ventricular arrythmias (TAKE WITH MEALS)
- LIVER metabolized
Ic - Propafenone
- sodium channel blocker: use dependent
- good Afib med in WOMEN
Ic - Propafenone: adverse effects
- metallic taste, constipation
- some B-blocking properties so can be a problem in asthma & Raynaud’s Syndrome
- CAN RAISE INR IN PATIENTS ON WARFARIN
- MEN get more side effects
Ic - Propafenone: metabolism
LIVER
Ic - Flecainide
- sodium channel blocker: use dependence
- great drug in HEALTHY PEOPLE
Ic - Flecainide: when & when not to give
- uses: PACs, PVCs, outflow tract arrhythmias, Afib
- don’t give: CHF, CAD, FLUTTER
Ic - Flecainide: metabolism
- primary renal, some hepatic (p450)