Cardiovascular stimulants

Question 1

All the cardiac stimulants raise heart rate except?

Answer 1

Norepinephrine and phenylephrine

Question 2

All raise BP except

Answer 2

isoproterenol

Question 3

Direct acting drugs stimulate what?

Answer 3

postsynaptic receptors

Question 4

Indirect acting drugs do what?

Answer 4

Increase the availability of NE or E

Question 5

Mixed acting drugs do what?

Answer 5

Both direct and indirect effects

Question 6

Which of the Cardiovascular stimulants in mixed acting?

Answer 6

Ephedrine

Question 7

What is the effect of Reserpine on mixed acting drugs

Answer 7

It reduces their effect on the heart

Question 8

All the cardiac stimulants raise heart rate except

Answer 8

Norepinephrine and phenylephrine

Question 9

What are some ways in which indirect acting drugs increase the availability of NE or E?

Answer 9

they release or displace NE from sympathetic nerve varicosities,
They block transport of NE into sympathetic neurons (cocaine)
They block metabolizing enzymes, MAO or COMT

Question 10

What the hell does Reserpine do?

Answer 10

It depletes NE from sympathetic neurons….It abolishes the activity of indirect acting drugs and/or blunts the effects of mixed acting drugs.

Question 11

Norepinephrine

Answer 11

Lowers pulse rate but increases blood pressure by increasing TPR

Question 12

Epinephrine

Answer 12

Raises pulse rate but lowers TPR so blood pressure stays about the same

Question 13

Isoproterenol

Answer 13

Raises pulse rate a lot, lowers bp though because TPR drops like a rock

Question 14

Epinephrine effect on pulse pressure

Answer 14

it goes up (systolic increases more than diastolic)

Question 15

Explain the epinephrine’s effect on vasodilation/constriction

Answer 15

It does both but the vasodilatory Beta 2 receptors are more sensitive than the vasoconstrictive alpha receptors so vasodilation wins

Question 16

Subcutaneous epinephrine

Answer 16

Local vasoconstrictive effect. Drives blood pressure up an dCO up. Raise HR, CO, and left ventricular work

Question 17

Epinephrine’s effect on the heart

Answer 17

Raises HR, CO, and O2 consumption.
Does this by accelerating the relaxation rate of ventricular myocytes, accelerates SA depolarzation, raises the amplitude of the action potential, activates latent pacemaker cells, shortens AV node refractory period

Question 18

Epinephrine toxicity

Answer 18

cerebral hemorrhage, ventricular arrhythmias, angina

Question 19

Dopamine

Answer 19

metabolic precursor of E and NE. Its precursor is given to treat parkinson’s disease

Question 20

Where is Dopamine synthesized and released

Answer 20

Proximal tubule

Question 21

In what conditions is dopamine said to have acute benefits?

Answer 21

in coronary heart disease and rhumatic

Question 22

Low dose dopamine has what effect? .5-3 mcg/kg/min

Answer 22

Predominantly works on D1 receptor to vasodilate in the kidneys, can improve GFR in patients with dimineshed perfusion

Question 23

Moderate dose dopamine? 2-10

Answer 23

predominantly cardiovascular effects. Increases cardiac output by increasing contractility more than HR

Question 24

High dose 10 and up

Answer 24

Vasoconstriction

Question 25

Dobutamine

Answer 25

Inc CO without affecting HR. Used for short term treatment of cardia decompensation

Question 26

Isoproterenol

Answer 26

CO goes up and TPR goes way down. Its effect is on Beta receptors way more so than alpha

Question 27

When is isoproterenol used?

Answer 27

To stimulate heart rate in ppl with bradycardia or heart block

Question 28

Phenylephrine

Answer 28

Inc BP without HR. Pretty much all ALpha agonist. Used to treat hypotension

Question 29

Ephedrine

Answer 29

Orally active drug. Used to treat hypotension b/c it raises HR and TPR