FINALS TDM/ cardiotropics Flashcards
Involves the analysis and evaluation of circulating concentrations of drugs in blood
TDM/ Therapeutic Drug Monitoring
To ensure that a given drug dosage produces maximal therapeutic benefit and minimal toxic adverse effects
TDM/ Therapeutic Drug Monitoring
Indications of TDM
1.Consequences of over- and under-dosing are serious
2. Narrow margin of safety
3. Good correlation between circulating concentrations and therapeutic or toxic effects
4. Change in patient’s condition that may affect circulating drug concentrations
5. Occurrence of drug interactions
6. Monitoring patient compliance
The rate at which the drug is absorbed is dependent upon the route of administration
Tablets & capsules require dissolution; liquids are rapidly absorbed
Transport mechanism: passive diffusion
Weak acids are absorbed in the stomach; weak bases in the intestine
Absorption
FACTORS AFFECTING ABSORPTION
CPIP
Changes in intestinal movement
pH
Inflammation
Presence of food or other drugs
Single most important factor
Timing
Peak concentrations
1 hour after an orally administered dose
SAMPLE COLLECTION
Serum or heparinized plasma
Used to treat congestive heart failure and cardiac arrhythmias
Act on the conduction system of cardiac muscle
Net effect : slow down electrical conduction
CARDIOTROPICS
Rapid sodium channel blockers
Class I
Quinidine
Class I
Procainamide
Class I
Lidocaine
Class I
Phenytoin
Class I
Beta adrenergic blockers
Propranolol
Class II
Potassium channel blockers
Amiodarone
Class III
Calcium channel blockers
Verapamil
Class IV
Digoxin and Digitoxin
DIGITAL GLYCOSIDES
Inhibits membrane Na+-K+-ATPase
Decreases K+ and Mg+ and increases Ca+
Rapid onset of action : 1-2 h after oral administration
Digoxin
Slower onset of action (1-4 hours oral)
Active metabolite : digoxin
Digitoxin
Local anesthetic
Acute control and prevention of ventricular arrhythmias after myocardial infarction
Toxicity : convulsions, coma, respiratory depression, bradycardia, hypotension
Lidocaine
For supraventricular and ventricular arrhythmias
Common formulation: quinidine SO4 & quinidine gluconate
Toxicity : cinchonism: vertigo, tinnitus, headache, visual disturbances and disorientation
Quinidine
Supraventricular or ventricular arrhythmias
Metabolite : n-acetylprocainamide
Toxicity : reversible lupus-like syndrome w/ elevated ANA titers, urticaria, rash, agranulocytosis and nephrotic syndrome
Procainamide
Antagonizes effects of epinephrine on the heart, arteries and arterioles of skeletal muscles and on the bronchus
Vasodilator: angina pectoris, hypertension
Propanolol
For life threatening ventricular arrhythmias
Amiodarone
For angina, hypertension and supraventricular arrhythmias
Verapamil
