Dopamine vs Dobutamine | MOA, Pharmacology, Vasopressor, Inotrope

By Adem Lewis / in , , , , , , , , , , /

Okay everybody, this is Jon with
Today, we re gonna talk about dopamin versus dobutamine. And we re gonna have a chart online
that you can download to PDF and it will kind of go over everything we talked about here,
just the basic differences with dopamine and dobutamine. And also, it will cover some of
the vasopressors or some of the vasopressors and their effects on the systemic vascular
resistance as well as cardiac output. So, you re gonna find that at Alright. So, why are we talking about dopamine
versus dobutamine? Well, the reason is, there seems to be some confusion. There was confusion
in my mind as well, obviously, of what dopamine and dobutamine are and their differences.
That s probably due to the names being somewhat similar and the fact that they re given in
similar situations. Okay. So, let s talk dopamine versus dobutamine. So, first of all, we need
to understand that dopamine is a vasopressor, dobutamine is not a vasopressor. That s the
first thing you really need to understand. Okay. Dopamine is actually a vasopressor,
it is actually an alpha 1 adrenergic agonist. So, what that means is that it s going to
actually act on this alpha 1 receptors in the central nervous system, and by doing that,
that s actually is going to lead to an increase in systemic vascular resistance. So, these
alpha 1 receptors are all along our vessels here okay. So, we have these little alpha
1 receptors on our smooth muscles and our, you know, which includes our vessels, and
what happens is, dopamine will actually go and act on these, and by acting on those,
it s gonna increase vasoconstriction. So, it acts on these alpha 1 receptors, these
vessels are gonna vasoconstrict, become tighter and that s gonna lead to increased systemic
vascular resistance. Okay, so, it s gonna increase that vessel squeeze. Now, Dobutamine,
on the other hand, is a positive inotrope. Now, you remember, let s draw a little heart
here, so here s our heart, and what these inotropes do, inotrope refers to the squeeze
(How do you spell squeeze? Something like that). So, inotrope refers to the squeeze
of our ventricles and so what positive inotropes actually do is they cause a greater squeeze
which is going to increase our cardiac output. So, it s gonna cause this left ventricle here
to squeeze a little bit harder and that s going to lead to more output here from our
aorta. Okay, so, the best way to think of this is, so, dopamine vasopressor, alpha 1
agonist. Dobutamine actually works on our beta 1 receptors in our central nervous system.
So, our beta 1 receptors, they are primarily found on the heart. And, we talked about this
a little bit earlier in another video about beta blockers and things like this. But, beta
1 receptors are essentially, they are found in the heart. Okay, so, when beta 1 receptors
are stimulated, this is part of our sympathetic nervous system, so, it s part of our fight
or flight. So, as these receptors are stimulated, it s going to increase our heart rate, increase
cardiac output, etc, etc. So, what happens is, we get beta blockers to block all these
effects, right, to block our beta receptor. Dobutamine, on the other hand, works to increase
the effects of our fight or flight response, basically. So, dobutamine is positive inotrope,
works on our beta receptors and it increases our cardiac output that way, it s a positive
inotrope. So, the best way for me to remember this is dobutamine has a B in it, okay, so
here s dobutamine with B and I think of that as beta, okay, so it s a beta agonist. So,
it s going to increase the effects of the beta receptors. Dopamine, on the other hand,
so, there s no B in it, so it s an alpha agonist and what it s going to do is, is it s going
to be a vasopressor. On the other hand, these beta receptors do not lead to those vasopressive
effects. Okay, so there s a quick overview for you. Let s go over to this chart that I have here
and we ll talk about some of these things on this chart here. So, dopamine is a vasopressor,
dobutamine is not, it s an inotrope, not a vasopressor. Dobutamine, with a B exhibits
primarily beta 1 effects, to aid in increasing cardiac output. And dopamine, depending on
the dose, will exhibit an alpha 1 effect leading to vasoconstriction and therefore an increased
systemic vascular resistance. They will also exhibit a beta 1 effect that lower doses.
Dopamine is a great medication for septic shock because it will contribute to increased
systemic vascular resistance. And, dobutamine, on the other hand, is generally given to increase
cardiac output and it s used in heart failure and cardiogenic shock. Because these doses,
it will lead to less myocardial oxygen demand, so that s great in heart failure and cardiogenic
shock. Okay. So, again, dopamine, for example, great
in septic shock, because in septic shock, remember what s happening here is we re having
this massive vasodilation and so we give our dopamine to go act on these alpha receptors,
and that leads to this vasoconstriction and increased systemic vascular resistance. So,
this is dopamine. Dobutamine, over here, it s got a B in it, it s our beta. So, what happens
with dobutamine, it s great for like heart failure where our ventricles aren t wanting
to contract, they re dilated or whatever, in cardiogenic shock as well. These cardiogenic
shock are primary insult as a broken pump, so we have a decreased cardiac output, heart
failure, we re also gonna have decreased cardiac output. So, it s a great option for heart
failure and cardiogenic shock because it s gonna increase this squeeze and it s gonna
push more blood out here through the aorta, okay. So, that s why dopamine and dobutamine
are given in different situations. Best way to remember this is, dobutamine, B , beta,
beta 1 receptors are on the heart. Dopamine, it s a vasopressor, works on the alpha 1 receptors. Okay, so, what we ll be giving away over
is going to be this little chart here. What I like about it also is it takes different
vasopressors and it ranks them in order in their effect in systemic vascular resistance
and cardiac output. Okay, so, this is a great little chart here. Go over there, it s free
to use, free to distribute to whoever you want with, and be sure to check this out on
youtube and listen to other podcasts. We appreciate you listening. Contact me, this is Jon with at [email protected] Thank you very much.
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24 thoughts on “Dopamine vs Dobutamine | MOA, Pharmacology, Vasopressor, Inotrope

  1. Love your podcasts, Jon. Listened to this one in my car, but the visuals are such a huge help.  Thanks for all you're pouring into us!

  2. Hello sir, I just thought you should know the link to download the material on Dopamine is not working. Otherwise, great videos.

  3. Sir can you make it clear about dopamine is it that dopamine is a +inotropic and chronotropic and why it has no effect on heart rate ty

  4. You should mention three dose effect of dopamine. Low dose on renal (D1), moderate dose effect on B1, higher dose effect on a1..

  5. John you just saved my life with a simple "B" in DoButamine!!!
    I loved the contrast to BetaBlockers!!! I'll never forget the diff between these two meds again!!!
    Hudson Valley NY
    Amazing tips and so simple and straightforward!
    Thanks again from a loyal subscriber and grateful nursing student!
    Debbie Q
    SUNY Orange

  6. I did something stupid yesterday i am new new icu nurse the doctor start my pt on dputamine for the cardiac output but suddenly pt crusshed so i increase doputamine dose from 2 mcg/kg/min to 5 thinking it well help thank you for this great explanation i learned alot

  7. Nice video, but am sure you might have gotten a lot of people confused. Dopamine has beta adrenergic effect at Medium dose, and alpha effect at high doses. I wont outrightly call Dopamine a vasopressor. Also Dopamine causes Tachycardia (beta 1 effect) and dobutamine has inotropic but less chronotropic effect (still Beta 1)….your audience needs all these clarification.

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