Let's review this section.
Muscarinic receptors are located on your eyes, your
heart, lungs, GI tract, sweat glands and urinary bladder.
The muscarinic receptors are activated by acetylcholine
and that's why they're considered cholinergic receptors.
Cholinergic drugs enhance the
effects of acetylcholine
and increase the actions of the
parasympathetic nervous system.
anticholinergic drugs competitively
block the effects pf acetylcholine,
and then reduce the parasympathetic
actions and increase sympathetic ones.
So an effective way to study cholinergic
drugs is to make sure that you understand
the receptors that are involved
with each particular drug.
If the drug is an agonist or an antagonist, and you
can easily remember the effects of the medication.
Now look at bethanechol.
It selectively activates the
muscarinic receptors on the bladder.
It's an agonist and it's used
to treat urinary retention.
Bethanechol is used in postpartum patients and
in patients whose bladder has a neurogenic atony
to help relieve that urinary retention.
you wanna be careful with bethanechol
even if it's likely won't happen
but patients with asthma and cardiac problems, peptic
ulcers or intestinal obstruction might have some problems.
Now, stop right there.
Based on what you know about
receptors, see if you can recall
why we might have a chance of a problem with
a patient with each of those diagnoses.
Work your way through asthma, cardiac, peptic ulcers
and intestinal obstruction and then restart the video.
Okay anticholinergic drugs are also
known as parasympatholytic, remember?
That's because they stop the
So antimuscarinic drugs is another way of
saying that, and so is muscarinic blocker .
Before we go on from here, make sure you understand why
all of those terms are referring to similar responses.
Okay, so anticholinergics produces selective
blockade of muscarinic receptors,
not all the cholinergic receptor
but they hit some of them.
Most muscrinic receptors are on structures that
are innervated by the parasympathetic nerves,
that's why we can so closely align it with
the parasympathetic nervous system response
or a sympathetic-like response.
Atropine is a muscarinic
and we use it for increasing the heart rate,
bradycardia when the patient is symptomatic.
Remember if they are super strong athletes,
don't go slim on atropine in them,
If they're symptomatic with it, their blood
pressure is too low, they feel really weird.
or they're unconscious, that would
be a time to give the medication.
And finally, mushroom poisoning is excessive
amounts of muscarinic agonist exposure,
and can be treated with a muscarinic
abntagonist like atropine.
Thanks for watching our video today and we
hope you survive mushroom poisoning!