Pharmacology - Drugs, MOA, AE, toxicity, uses Flashcards
Anti arrhythmic classes
No Bad boy Keeps Clean
I: Na channel blockers
II: Beta blockers
III: K channel blockers
IV: Ca channel blockers
Class I Na+ Channel Blockers
Decrease slope of phase 0 in myocytes
Increase ERP and QT interval
“Double Quarter Pounder, Mayo, Lettuce, Tomato, Fries Please”
1A: disopryamide, quinidine, procainamide
1B: mexiletine, lidocaine, tocainide
1C: flecainide, propafenone
procainamide - use for WPW (can cause drug induced SLE)
Quinidine - cause cinchonism, thrombocytopenia, torsades
Lidocaine - use for acute VT, digitalis induced arrhythmia, tachyarrythmia post MI
1Cs use as last result for VT to prevent progression to Vfib, proarrythmics
Class II Beta blockers
decrease cAMP, decrease Ca currents
Decrease slope of phase 4 in pace maker cells
Propranolol, esmolol, metoprolol, atenolol, timolol
Use: VT, SVT - slowing ventricular rate in a fib and flutter
Caution: exacerbate asthma, CHF
Cause bradycardia, AV block
masks effects of hypoglycemia
Tx toxicity: glucagon
Class III K+ channel blockers
Work at phase 3
Increase ERP and QT interval
Sotalol, ibutilide, bretylium, dofetilide, amiodarone
Use: rhythm control in afib - sotalol, amiodarone
WPW - amiodarone
All cause torsades
Amiodarone toxicity
pulmonary fibrosis hepatotoxicity hypo/hyperthyroidism (40% I) corneal deposits photodermatitis - gray-blue skin discoloration constipation neuro effects
CV: bradycardia, heart block, HF
Class IV Ca2+ channel blockers
Decrease slope of phase 0 in pacemaker cells
Increase ERP
Verapamil, diltiazem
Toxicity: constipation, flushing, edema
CV: HF, AV block, sinus node depression, torsades
Adenosine
increases potassium efflux - hyper polarizes, Ca2+ can’t co into myocytes
Prevents depolarization
use for SVT - diagnostic
Toxicity: flushing, hypotension, chest pain
Blocked by theophylline (asthma, COPD)
