What are two types of GI receptors?
- Cholinergic (parasympathetic innervates the GI tract. When these neurons fire, they increase motility [push food], these neurons release Ach)
- Opioid (mu) receptors (when these neurons fire, they slow down GI motility–why when you take a lot of morphine [opioid] you get constipated)
So cholinergic increase motility and pushes food out. What happens when we give an anti-cholinergic?
We can slow down bowel motility and halt diarrhea
What is it called when you add something to the body?
Exogenous
Exogenous opioids slow down [decrease] the GI motility, which is what we would want in patients with _____.
Diarrhea
What are the three drugs that slow down motility?
Dicyclomine
Loperamide
Diphenoxylate/atropine
Which diarrhea drug isn’t given for your typical diarrhea. What is it given for instead?
Dicyclomine; it is given for a disorder that can CAUSE diarrhea
What disease is dicyclomine given for?
Irritable Bowel Syndrome (IBS)
How many Americans are affected by IBS?
20%
More than ___ visits to a GI doctor are about IBS.
1/4
What is IBS?
Involves having pain that is relieved by defecation
Is dicyclomine an anticholinergic or an exogenous opioid?
Anti-cholinergic
Does dicyclomine slow down bowel motility?
Yes
What is Loperamide given for?
Diarrhea
What receptor does Loperamide work on?
Mu
Loperamide and meperidine (another opioid) are very structurally similar to one another. What is the key difference between them?
Loperamide will not cross the BBB
Loperamide is an opioid. Do we see pain relief, euphoria, or addiction with this drug?
NO! It doesn’t cross the BBB so, you don’t have those effects even though it is an opioid
What is the combination drug used for diarrhea?
Diphenoxylate/atropine
What is diphenoxylate (an anti-cholinergic or an opioid)?
An opioid
Can diphenoxylate dissolve in water?
No
What happens if you take too high a dose of diphenoxylate?
You can get a “buzz”
What drug did they add to dipphenoxylate so you can’t get a buzz with the opioid if you take too high a dose?
Atropine
What kind of drug is atropine?
Anti-cholinergic
What situations is atropine used in a lot?
Code situations
At a low dose, atropine _____.
Doesn’t do much
At a high dose, atropine ______
Has anticholinergic side effects
Can you get diphenoxylate/atropine OTC?
No; prescription only
What CSA schedule is diphenoxylate/atropine?
5
What are the adverse effects to dicyclomine?
Dry eyes/blurry vision (can’t see)
Urinary retention (can’t pee)
Dry mouth (can’t spit)
Fatigue
Dicyclomine is on ____.
Beer’s criteria list (avoid in geriatrics unless for acute comfort care)
What are the adverse effects of loperamide?
Nothing stands out, Very well tolerated
What are the adverse effects of diphenoxylate/atropins?
Nothing stands out, very well tolerated (unless you abuse them, then the anti-cholinergic effects)
What is the important purpose of diarrhea?
It helps expel infectious agents or irritants from the body
In the hospital, do we give a lot of anti-diarrhea?
No–instead go after the cause!! If there is an infection, we fight the infection
What is another reason for diarrhea?
Food intolerance (lactose intolerance)
T/F: Drugs that trigger opioid receptors in the gut don’t necessarily treat the underlying cause.
True
If someone has an acute infection diarrhea, what drugs do we NOT want to give and why?
Drugs that trigger opioid receptors because they don’t treat the underlying cause