whysosong

Class Ia :
* Quinidine
-> Inh. vagolytic
-> Anticholinergic
-> Cinchonism
-> thrombocytopenia

* Procainamide
-> Met. way:N-acetylation => SLE
-> Active Met.:NAPA

* Disopyramide
-> Anticholinergic(atropine like)

※ Class Ib :
* Lidocaine
-> Met.:MEGX => Induce epilepsy
-> Non PO effect
-> Digoxin overdose antidote

* Phenytoin
-> Elimination order:LD:1 ; HD:0
-> Tx digitalis-induced tachyarrhythmias
-> Antiepilepsy

* Tocainide
-> SE: Epilepsy inducer
-> Only this "-cainide" is Class Ib

* Mexiletine
-> SE: Epilepsy inducer

※ Class Ic :
* Flecainide
-> Mechanism: Na.K.Ca blocker => Not pure
-> SE: Overlay CHF

* Propafenone
-> Mechanism: Na.K blocker
-> Met.: Hepatic & Renal
-> SE: Bronchospasm => Asthma CI

--------------------

※ Class II
* Propranolol
-> SE: CHF , bronchospasm
-> Cannot use with Verapamil => Overlay CHF

** Sotalol
-> Two types: Nonselective beta blocker => Class II
　　　　　　　 K channel blocker => Class III
-> Met.: Renal

※ Class III
* Bretylium
-> Mechanism: Inh. NE reuptake
-> Tx: Tachycardia , Ventricular fibrillation

* Amiodarone
-> I => SE: Gray man syndrome
-> Nonspecific: Na,K,Ca & alpha,beta blocker & Muscarinic
-> SE: Gray man syndrome , Pulmonary fibrosis
-> Higt lipophilic => Half life: 3 month
-> Broad antirrhythmic drugs
-> Amiodarone is CYP inhibitor => Inh. other drugs met.

* Ibutilide, Dofetilide
-> Pure Class III drug
-> SE: Torsade de pointes
-> CI: Sulfanamide hypersensitive

** Sotalol

※ Class IV
* Verapamil
-> Papaverine indivate
-> Mechanism: L-type CCB
-> SE: Overlay CHF , A-V block(Antidote:Atropine,Ca,Beta agonist)
-> Tx: PSVT , Reentrant PSVT , Cancer(Block P170 glycoprotein)

* Diltiazem

--------------------

※ Others:
* Adenosine
-> Mechanism: Active adenosine receptor => prolong conduction
　　　　　　　 Active K channel => Cause Hyperpolarization
-> SE: Dyspnea, Hypotension, Chest pain
-> Half life: 30 sec.
-> Met. Enzyme: Adenosine deaminase => Inh. other drug met.
-> Tx: PSVT, Reentrant PSVT, AV nodal reentry tachycardia

=======================================================

Only "Class Ia & Class III" cause QT prolong, inducing Torsade de pointes.