[mark2climb]

Has anyone out there encountered beta agonist sensitization in their practice? For example, your cardiogenic shock pt who was doing fine on dobutamine starts to require a higher and higher rate?

I came across an article that mentioned how using a microscopic amount of metoprolol would help the receptors not develop a resistance. Is anyone out there doing that?

[CVICURN2003]

Originally Posted by mark2climb

Has anyone out there encountered beta agonist sensitization in their practice? For example, your cardiogenic shock pt who was doing fine on dobutamine starts to require a higher and higher rate?

I came across an article that mentioned how using a microscopic amount of metoprolol would help the receptors not develop a resistance. Is anyone out there doing that?

All of our heart pts get lopressor no matter their b/p even if we have to increase the pressors. Usually it is 12.5 mg or less.

[mark2climb]

What if the patient is on inotrpes, specifically dobutamine? It seems a bit counter intuitive but I think there is a physiologic basis for using very low dose metoprolol while the patient is still on an inotrope like dobutamine.

Here the link to an article: http://cogprints.org/4093/

[Summitk2]

Originally Posted by CVICURN2003

All of our heart pts get lopressor no matter their b/p even if we have to increase the pressors. Usually it is 12.5 mg or less.

Is this for beta agonist desensitization or for Afib prophylaxis? I've only heard of it for the latter... I'm curious now--thanks for the article!

summitk2

[mark2climb]

This is not for AFib prophylaxis. The dosing is much too low.

The reason I brought this up is that I had a pt in cardiogenic shock from a massive anterior wall MI. He had Q waves on arrival to the ED with troponin that was on it's way down. We put him on dobutamine at first but saw the effect decrease after 48 hrs so the cardiologist changed over to milrinone. I asked him why and he mentioned the desensitisation phenomenon. I did some surfin' online and found this article along with others on beta agonist desensitisation and how adding a little touch of beta blocker can not only prevent it but also maximize the effect of the beta agonist. It dosen't seem to make sense but it's a phenomenon that's been observed in animal tissue.

I was just curious to see if anyone else had heard of it or has been using a beta agonist and antagonist at the same time to ward off desensitisation.