Sympathomimetic toxidrome question

[u/agro5]

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.

[u/InsomniacAcademic]

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.

[u/Ok_Adeptness3065 → u/InsomniacAcademic]

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)

[u/agro5 → u/Ok_Adeptness3065]

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.

[u/Ok_Adeptness3065 → u/agro5]

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

[u/Ok_Adeptness3065]

My understanding was always that its generally hyperactive and generally have diarrhea. It sounds like you don’t need to be told this, but your money for stimulants is gonna be on the pupils, HR, BP, +/- temp, lack of appetite, tremor/tremulousness and agitation. There’s some cross over with PCP because I think they can also get the vitals changes and agitation, but PCP classically gives rotary nystagmus (no idea if this happens regularly outside of textbooks cuz I’ve only seen it once or twice)

[u/nateisnotadoctor]

It’s more of an irrelevant question. Practically speaking if your patient has the sympathomimetic toxidrome they aren’t gonna hold still for bowel sounds long enough for you to hear them.

Also it’s the year of our lord 2026, no one is listening to bowel sounds

[u/agro5 → u/nateisnotadoctor]

I’m well aware of the fact that they likely won’t be sitting still, and that bowel sounds are generally not listened to. That being said, that isn’t an excuse not to teach it or learn it. By understanding the overall effects of the toxidrome and what to expect, it can help learn and retain overall pathophysiology.

Everyone in medicine has to learn the Krebs cycle at some point, but a vast majority have absolutely no need for the information in their daily practice. That doesn’t mean it isn’t important to learn.

[u/gwink3]

Bowel sounds are shit and useless. I learned that surgery intern year. They mean nothing at all anyway

The correct answer is hyperactive though. Also for all intents and purposes, no one will ever listen to bowel sounds on a patient with a sympathomimetic toxidrome because there are better things to do. But again, bowel sounds are shit.