drugs new

Question 1

carvedilol

Answer 1

“non selective beta blocker with alpha 1 activity especially useful for congestive heart failure moderate lipid solubility eliminated by liver labetolol is another combination blocker”

Question 2

metoprolol

Answer 2

“beta 1 selective beta blocker with moderate lipid solubility eliminated by liver”

Question 3

propranolol

Answer 3

“non selective beta blocker high lipid solubility eliminated by liver”

Question 4

atenolol

Answer 4

“beta 1 selective beta blocker low lipid soluble eliminated by kidney longer action –> can be dosed once daily class II antiarrhtyhmic”

Question 5

atropine

Answer 5

“parasympathetic antagonist (muscarinic) competitive antagonist blocks vagal response might stop AV block –> for ex inferior wall MI or dig toxicity almost no CNS effect at clinical doses given by IV”

Question 6

procainamide

Answer 6

“class Ia antiarrhythmic tragets Ina and Ik depresses fast response excitability and increases APD”

Question 7

lidocaine

Answer 7

“class Ib antiarrhythmic Targets Ina depresses fast response excitability especially in depolarized tissue *not useful at normal resting potential”

Question 8

flecainide

Answer 8

“class Ic antiarrhythmic depress fast response excitability in noemal and depolarized tissue”

Question 9

dofetilide

Answer 9

“class III antiarrhythmic targets Ik prolong APD without depressing excitability in fast response tissue”

Question 10

verapamil

Answer 10

“Ca cahannel blocker Ica targeted depress conduction and excitability in slow response tissue (AV node, SA node) effective in tx of paroxysmal SVT and tx of angine (decrease myocardial o2 demand and increase coronary blood flow) & tx htn (reduce SVR) *notable side effect is constipation”

Question 11

what are class I and III antiarrhythmics used for

Answer 11

“vent tachy atrial fib AV reentry”

Question 12

what are class IV antiarrhythmics, digoxin and adenosine used for

Answer 12

AVNRT

Question 13

what is unique about class Ia antiarrhythmic

Answer 13

also blocks Ik so increased action potential duration

Question 14

factors that modify the strength of sodium channel blockade

Answer 14

“Ib< IA< IC resting membrane potential - more potent when more negative hear rate - more potent at faster heart rate”

Question 15

factors that increase the effect of Ik blockade on APD

Answer 15

“slow hear rates low extracellular K low extracellular M”

Question 16

effect of digoxin in arrhythmia

Answer 16

“enhance vagal by increasing muscarinic receptor decress I ca and increase I K ach *only drug that acts on slow response tissue that is a positive inotrope slow onset of effect and duration greater than 1 day!”

Question 17

adenosine

Answer 17

“adenosine receptor agonist decrease calcium current and icnrease potassium current from ach onset of action and duration of effect is seconds!!”

Question 18

what is major determinant of ERP in fast and slow response tissue?

Answer 18

“fast - APD slow- recovery of ca channel”

Question 19

selectivity of calcium channel blockers

Answer 19

“verapamil - cardiac nifedipine - vascular diltiazem cardiac and vascular”