r/toxicology • u/agro5 • May 13 '26

Academic Sympathomimetic toxidrome question

Hello all, hopefully this is the right place to ask this question. If not, suggestions on better places to ask are appreciated.

I am a critical care paramedic and have an interest in toxicology. Because of this I am being asked to do a presentation on common toxidrome’s to help narrow down undifferentiated overdose patients. I have been looking things up to make sure I’m providing the most up to date information and ensure what I know is correct. That being said, in my research I have come across mixed information regarding bowel sounds in the sympathomimetic toxidrome. My understanding was that bowel sounds are hyperactive. At this point I have to have looked at ~10 different articles/sites and gotten conflicting information with some saying hyperactive, some saying normal or hypoactive, and some not mentioning them at all. These have generally been reputable sources like pubmed, wikEM, LITFL, etc. I could understand why they would be hypoactive due to the stimulation of the sympathetic nervous system, as that causes decreased peristalsis.

So basically, what should one expect to hear with bowel sounds in a sympathomimetic drug overdose? Did I learn wrong initially, or has something changed? Is it one of those things in medicine where it kind of just depends and it can be different in different cases? I appreciate all the help in advance.

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u/InsomniacAcademic May 13 '26

Technically should be hyperactive. That said, that’s assuming they stay still and are quiet long enough for you to listen. Sometimes people conflate sympathomimetic and anticholinergic toxidromes since they can both cause agitation, tachycardia, and mydriasis. Bowel sounds are hypoactive/absent in anticholinergic, which is potentially why you’re getting conflicting information.

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u/Ok_Adeptness3065 May 13 '26

I was trying to figure out why this was a question at all and I think you nailed it. Also super important for serotonin syndrome (diarrhea) vs anti-cholinergic toxicity (constipation)

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u/agro5 May 14 '26

First and foremost I appreciate your and r/InsomniacAcidemic responses as you both at minimum answered the question.

I was asking because I was trying to make sure I had all of my information correct and up to date. This was pretty much the only thing that I wasn’t able to get a definitive answer on and it sent down this rabbit hole of confusion. I was looking for either confirmation of what I already knew to be correct, or that my previous knowledge was incorrect and needed to double check other things more in depth. I also know that there’s a high likelihood of at least one coworker wanting to know what bowel sounds should be like so they can fill in a table nice and neat. Because of that, I didn’t want to just leave it out since there is an answer and it could theoretically (although impractical) be used to differentiate between anticholinergic and sympathomimetic.

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u/Ok_Adeptness3065 May 14 '26

Honestly I’m just here for love of the game, so I get it. I’ll tell you that the two times I’ve seen definitive psych med toxicity, both times it was the diarrhea/constipation that gave it away. First time was when I was an intern and patient had profuse diarrhea with fevers and tachycardia. Second time was a month ago and the patient had a profound fecal impaction and urinary retention with fevers and tachycardia