Methohexital; Histamine Release

Published

I know thiopental is a histamine releaser but what about methohexital? I can't find it in Barash and I don't have a Miller to look at.

Up Vote Up Vote ×

I was never taught this.

Stoelting says that the mild and transient decrease in SBP that accompanies induction of anesthesia w/barbiturates is due to peripheral vasoldiation....Histamine release can occur in response to rapid IV admin of barbiturates, but this is rarely of clinical significance. Nevertheless, profound hypotension simulating an allergic reaction has been attributed to nonimmunolgically mediated histamine release evoked by thiopental. In an in vitro model, thiopental....evoke histamine release.

Miller says the primary CV effect of barb induction of peripheral vasoldilation resulting in pooling of blood in the venous system. Other factors are decrease in contractility and a refractory increase in HR. From what I can read under barb induction, thiopental does not involve histamine release.

However, after doing a Yahoo! search of "thiopental, histamine release", the first article to come up was www.anesthesia-analgesia.org/cgi/content/abstract/84/3/623 and some patients (5) had increased plasma levels of histamine after thiopental inductions.

Stoelting, as usual, is hard to get the take home points due to the wording. Can it happen? yes.

Clinically significant? no

Up Vote Up Vote ×
Specializes in I know stuff ;).

Are you all treating with benedryl prior to administration then?

I run into the same thing with Morphine all the time. MS causes a histamine mediated hypotension as well, so when i have those chest painers in some degree of cardiogenic shock i either use benedry then MS (no hypotension) or i just go right for the fentanyl.

Up Vote Up Vote ×
Are you all treating with benedryl prior to administration then?

I run into the same thing with Morphine all the time. MS causes a histamine mediated hypotension as well, so when i have those chest painers in some degree of cardiogenic shock i either use benedry then MS (no hypotension) or i just go right for the fentanyl.

Honestly haven't used thio that often. Most often we use propofol on majority of people and if their cardiac hx warrants it, they get Vomidate...sorry I couldn't help myself there. I meant Etomidate.

The long duration of thio and E1/2T of 11.6 hours is not necessiarily attractive. I read somewhere a researcher was conductiog essentially either field sobriety tests or driving simulators on individuals intubated with standard dosings of thio - these patients were flunking the tests up to 8 hours later. :nono:

Up Vote Up Vote ×
Specializes in I know stuff ;).

scary.

Up Vote Up Vote ×

According to Nagelhout, Methohexital may precipitate histamine release. Although the CV effects of this may be clinically insignificant (as mentioned in the above post), I would probably avoid it in asthmatics.

Up Vote Up Vote ×
Are you all treating with benedryl prior to administration then?

I run into the same thing with Morphine all the time. MS causes a histamine mediated hypotension as well, so when i have those chest painers in some degree of cardiogenic shock i either use benedry then MS (no hypotension) or i just go right for the fentanyl.

You can probably find a study somewhere that indicates that almost any drug you choose has the potential for histamine release (or some other adverse effect). Giving benadryl routinely because someone MIGHT have a little histamine release makes no sense. We'd be giving it to every single patient.

Methohexital is rarely used anymore - there simply aren't any good reasons to use it except on ECT's, where it seems to be the preferred drug by the psychiatrists. None of them ever get benadryl. Neither do the patients who get pentothal - or morphine - or vanco. It simply isn't a problem that's anywhere near a common enough problem to warrant giving benadryl as a matter of routine.

Up Vote Up Vote ×
You can probably find a study somewhere that indicates that almost any drug you choose has the potential for histamine release (or some other adverse effect). Giving benadryl routinely because someone MIGHT have a little histamine release makes no sense. We'd be giving it to every single patient.

Methohexital is rarely used anymore - there simply aren't any good reasons to use it except on ECT's, where it seems to be the preferred drug by the psychiatrists. None of them ever get benadryl. Neither do the patients who get pentothal - or morphine - or vanco. It simply isn't a problem that's anywhere near a common enough problem to warrant giving benadryl as a matter of routine.

Gotcha J dub.

Up Vote Up Vote ×
Specializes in I know stuff ;).

jwk

Again you show your lack of knowledge.

It has LONG been a fact and studied MANY times that morphine causes a histamine release in approximately 30-40% of people who are tx'd with it. This is countered with benedryl. This isnt new. However, since you have absolutely no background in medicine like an ICU/ER RN does who then becomes a CRNA i shouldnt be surprised. This is EXACTLY the difference between a CRNA and an AA.

You can probably find a study somewhere that indicates that almost any drug you choose has the potential for histamine release (or some other adverse effect). Giving benadryl routinely because someone MIGHT have a little histamine release makes no sense. We'd be giving it to every single patient.

Methohexital is rarely used anymore - there simply aren't any good reasons to use it except on ECT's, where it seems to be the preferred drug by the psychiatrists. None of them ever get benadryl. Neither do the patients who get pentothal - or morphine - or vanco. It simply isn't a problem that's anywhere near a common enough problem to warrant giving benadryl as a matter of routine.

Up Vote Up Vote ×
jwk

Again you show your lack of knowledge.

It has LONG been a fact and studied MANY times that morphine causes a histamine release in approximately 30-40% of people who are tx'd with it. This is countered with benedryl. This isnt new. However, since you have absolutely no background in medicine like an ICU/ER RN does who then becomes a CRNA i shouldnt be surprised. This is EXACTLY the difference between a CRNA and an AA.

You got personal in a previous post so now the gloves are off. If you want to bang brain buckets with me go get ten years of experience and published in a journal. You simply dont match up. Please, stop trying to gain acceptance on a nurses website for CRNAs, it is pathetic.

\

Mike, PUMP YOUR BRAKES MAN!!! :lol2: I can't wait to see J dub's response to that. Mike, J dub's has alot of anesthesia knowledge and he's right; you will never learn about benadryl and its effects in anesthesia in your ANESTHESIA pharm class when you start school.

I mean no disrespect by this, but I would wait to debate anesthesia until I've actually started anesthesia school. Its a totally different animal (or clowns); whichever you prefer.

Up Vote Up Vote ×
Specializes in I know stuff ;).

Hey Sigma.

I have no doubt that anesthesia is different. I dont, however, allow people who dont know me summarily dismiss what I have to say. Im not arguing the anesthesia side of it but the MS side of the argument which is common practice.

Sorry for the rant, but he was an ass earlier without provocation and i got angry. I should know better than to respond to Trolls.

Mike, PUMP YOUR BRAKES MAN!!! :lol2: I can't wait to see J dub's response to that. Mike, J dub's has alot of anesthesia knowledge and he's right; you will never learn about benadryl and its effects in anesthesia in your ANESTHESIA pharm class when you start school.

I mean no disrespect by this, but I would wait to debate anesthesia until I've actually started anesthesia school. Its a totally different animal (or clowns); whichever you prefer.

Up Vote Up Vote ×

Some personal thoughts. i have used thiopental and methohexital (Brevital) in thousands of cases. If either of them have a histamine response, it is minimal. I have used it on many, many asthmatics (almost endemic in my part of the country) and have not seen any significant histamine release.

One of the surgeons I work with requests benadryl on his facial plastic cases, because he thinks (it has been published, also) that it prevents a histamine response at the area of surgical discection. His patients do incredibly well and have little or no edema the next day.

I personally have the histamine response to morphine. Instead of pre-treating me with benadryl, just give me another narcotic. I recently had back surgery and dilaudid worked fine.

I am rather a purist--don't pre-treat much, hardly ever reverse anything, just watch the timing of drugs and watch the patients' response. There are a lot of problems with polypharmacy and reversal of most meds. In my opinion, but based on over 46 years of doing this.

Yoga CRNA

Up Vote Up Vote ×
+ Add a Comment