Cardio/Renal Flashcards
Antiarrhythmics class 1a Drug names
Quinidine
Procainamide
Disopyramide
Antiarrhythmics class 1b Drug names
Lidocaine
Mexiletine
(Phenytoin)
Antiarrhythmics class 1c Drug names
Flecainide
Propafenone
Antiarrhythmics class 1 Type
Na channel blockers
Antiarryhythmics class 1a MOA
Na channel blockers
Inc. AP duration
Inc. ERP (some K-channel blocking effects).
Prolongs QT interval.
Antiarrhythmics class 1a Clinical use
Na channel blockers
Atrial/ventricular arrhythmias (AFib, A-flutter; SVT, Vtach)
(esp. re-entrant and ectopic SVT, VT)
Antiarrhythmics class 1a Toxicity
Na channel blockers.
>Cinchonism (headache, tinnitus; Quinidine).
>SLE-like syndrome (procainamide).
>Heart failure (disopyramide).
>Torsades de pointes (prolonged QT interval).
Antiarrhythmics class 1b MOA
Na channel blockers
Dec. AP duration (preferential for ischemic or depolarized Purkinje and ventricular tissue).
Dec. ERP.
Antiarrhythmics class 1b Clinical use
Na channel blockers. Ventricular arrhythmias (post-MI)
Antiarrhythmics class 1b Toxicity
Na channel blockers
CNS stimulation/depression
Cardiovascular depression
Antiarrhythmics class 1c MOA
Na channel blockers
Markedly prolongs phase 0 depolarization.
Antiarrhythmics class 1c Clinical use
Na channel blockers
Life-threatening SVTs (atrial fibrillation).
Last resort in refractory Vtach.
Antiarrhythmics class 1c Toxicity
Na channel blockers
Pro-arrhythmic (CI in post-MI)
Antiarryhthmics class 2 Type
Beta-blockers
Antiarrhythmics class 2 Drug names
Metoprolol, Propanolol
Esmolol, Atenolol
Timolol, Carvedilol
Antiarrhythmics class 2 MOA
B-blockers (B1 antagonists at low doses, atenolol)
Dec. SA/AV node activity (dec. cAMP – dec. Ca – dec. phase 4 slope, dec. depolarization).
Inc. PR interval – dec. conduction through AV node.
Antiarrhythmics class 2 Clinical use
B-blockers
SVT
Ventricular rate control of A-fib and A-flutter.
Antiarrhythmics class 2 Toxicity
B-blockers. Impotence. Exacerbated COPD, asthma. CVS effects (bradycardia, HF, AV block). CNS effects (sedation, sleep disturbance). Can mask hypoglycemic signs.
Antiarrhythmics class 3 Type
K channel blockers
Antiarrhythmics class 3 Drug names
Amiodarone
Ibutilide
Dofetilide
Sotalol
Antiarrhythmics class 3 MOA
K channel blockers. Prolongs phase 3 repolarization. Prolongs AP duration. Prolongs ERP. Prolongs QT interval (ventricular contraction).
Antiarrhythmics class 3 Clinical use
K channel blockers.
A-fib, A-flutter
Vtach (amiodarone, sotalol)
Antiarrhythmics class 3 Toxicity
K channel blockers.
Torsades de pointes (sotalol, ibutilide).
B-blockade (sotalol).
>Amiodarone: pulmo fibrosis, hepatotoxicity, hypo/hyperthyroidism (40% iodine); photodermatitis, corneal deposits (acts as a hapten); CNS effects, CVS effects – check LFT, PFT, TFT.
Antiarrythmics class 4 Type
Ca channel blockers (nondihydropyridine)
Antiarrhythmics class 4 Drug names
Verapamil
Diltiazem
Antiarrhythmics class 4 MOA
Ca channel blockers. Prolongs phase 2. Dec. conduction velocity -- slow rise of AP, slow closing of Ca channels. Inc. ERP. Inc. PR interval.
Antiarrhythmics class 4 Clinical use
Ca channel blockers
Prevents nodal arrhythmias (SVT)
Rate control in A-fib
Antiarrhythmics class 4 Toxicity
Ca channel blockers Constipation, flushing, edema CVS effects (HF, AV block, sinus node depression)
Digoxin
Type
Cardiac glycoside
Digoxin
MOA
Inhibits Na/K ATPase – indirect inhibition of Na/Ca exchanger – Inc. intracellular Ca – positive inotropy (increases contractility)
Digoxin
Clinical use
> HF (inc. contractility).
>A-fib (decr. AV node conduction, depresses SA node).