Pharmacology: Katzung antiarrythmic drugs Flashcards
(49 cards)
Procainamide, Disopyridamide, and quinidine belong to which group of drugs?
They are group 1A anti-arrythmics
What is the MOA for Procainamide, Disopyridamide, and quinidine?
They block either inward sodium or inward potassium channels. This slows the conduction velocity, slows pacemaker activity and prolongs action potential and refractory period.
What are the clinical applications for Procainamide, Disopyridamide, and quinidine?
(1) Atrial and ventricular arrythmias particularly after myocardial infarction.
What are the adverse effects associated with Procainamide, Disopyridamide, and quinidine?
(1) increased arrythmias
(2) Hypotension
(3) Lupus like syndrome
What makes disopyramide different than the other group 1A antiarrythmics?
disopyramide has a longer duration of action and has extra toxicities that include antimuscarinic effects and heart failure.
What differnetiates quinidine from the other group 1A anti-arrythmics?
Quinidine has an extra toxicity called cinchonism which includes
(1) tinnitus
(2) headache
(3) GI disturbance
To which group of drugs do Lidocaine and Mexiletine belong?
They are Group 1B anti-arrythmics?
What is the MOA for Lidocaine and Mexiletine?
Highly selective and state dependent block of inward Na channels. Minimal effect in normal tissue.
What are the clinical applications for Lidocaine and Mexiletine?
(1) Ventricular arrythmias post myocardial infarction
(2) digoxin-induced arrythmias.
What are the adverse effects associated with Lidocaine and Mexiletine?
CNS sedation or exitation
What differentiates mexiletine from lidocaine?
Mexiletine has oral activity and a longer duration of action.
To what group of drugs does Flecainide belong to?
Flecainide is a group 1C anti-arrythmic
What is the MOA for Flecainide?
it causes a selective and state dependent block of inward Na channels. This leads to slowed conduction velocity and slowed pacemaker activity.
What are the clinical applications for flecainide?
refractory arrhythmias.
What adverse effects are associated with Flecainide?
(1) increased arrhythmias
(2) CNS excitation
To what class of arrhythmics do propranolol and Esmolol belong to?
The are Group 2 arrhythmics. (also they are beta blockers)
What is the MOA for propranolol and Esmolol?
They block beta receptors thus slowing pacemaker activity?
What are the clinical applications for propranolol and Esmolol?
(1) post MI as prophylaxis against death
(2) ventricular fibrillation
(3) Thyrotoxicosis
What are the adverse effects associated with propranolol and Esmolol?
(1) Bronchospasm
(2) Cardiac depression
(3) AV block
(4) Hypotension
To what class of anti arrhythmics do Amiodarone, Sotalol, Ibutilide and dofetilide belong to?
They are group 3 anti arrhythmics.
What is the MOA of amiodarone?
Strong inward K channel blocker that produces marked prolongation of the action potential and refractory period. Group 1 activity slows conduction velocity. Group 2 and 4 activity confer additional anti-arrhythmic activity.
What are the clinical applications for amiodarone?
(1) refractory arrhythmias
2) used off label in many arrhythmias. (broad spectrum of action
What are the adverse effects associated with amiodarone?
(1) thyroid abnormalities
(2) deposits in the skin and cornea
(3) pulmonary fibrosis
(4) optic neuritis
What is the MOA for Sotalol?
It blocks inward K channels and beta adrenoreceptors
