Jan 3, 2010

Vaughan Williams Classification of Anti-arrythmic Drugs

Class Action Drugs Caution
Ia

Sodium channel inhibition: prolong
repolarization

Quinidine, procainamide,
disopyramide

myocardial infarction, congestive
heart failure,
renal disease

Ib

Sodium channel inhibition: shorten
repolarization

Lidocaine

Proarrhythmias

Ic

Sodium channel inhibition: no effect on repolarization but reduce conductivity

Flecainide, propafenone

Structural heart disease, myocardial infarction, congestive heart failure

II

B-Adrenergic inhibition

Timolol, esmolol, atenolol, bisoprolol

Acute heart failure, bronchospasm

III

Potassium channel inhibition: prolong repolarization

Amiodarone, sotalol

Renal disease, pulmonary disease

IV

Calcium channel inhibition

Verapamil, diltiazem

Not in conjunction with B-blockers

Misc

Na-K ATPase inhibition: potentiate
parasympathetic response

Digoxin

Renal disease, hypokalemia

Types of Antibiotics:

Concentration-dependent activity of antibiotics: Rate of kill is related to peak concentration above breakpoint,

eg: Aminoglycosides, fluoroquinolones, amphotericin B and metronidazole

Time-dependent activity: Kill rates related to the length of time concentrations are sustained above breakpoint MIC.

eg: Penicillins, cephalosporins, macrolides, carbapenems, clindamycin, linezolid and glycopeptides