Muscarinic Receptors and Drugs: In a Nutshell (Nursing)

00:01 Let's review this section.

00:03 Muscarinic receptors are located on your eyes, your heart, lungs, GI tract, sweat glands and urinary bladder.

00:10 The muscarinic receptors are activated by acetylcholine and that's why they're considered cholinergic receptors.

00:18 Cholinergic drugs enhance the effects of acetylcholine and increase the actions of the parasympathetic nervous system.

00:26 anticholinergic drugs competitively block the effects pf acetylcholine, and then reduce the parasympathetic actions and increase sympathetic ones.

00:35 So an effective way to study cholinergic drugs is to make sure that you understand the receptors that are involved with each particular drug.

00:43 If the drug is an agonist or an antagonist, and you can easily remember the effects of the medication.

00:50 Now look at bethanechol.

00:52 It selectively activates the muscarinic receptors on the bladder.

00:56 It's an agonist and it's used to treat urinary retention.

01:00 Bethanechol is used in postpartum patients and in patients whose bladder has a neurogenic atony to help relieve that urinary retention.

01:08 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.

01:20 Now, stop right there.

01:22 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.

01:31 Work your way through asthma, cardiac, peptic ulcers and intestinal obstruction and then restart the video.

01:40 Okay anticholinergic drugs are also known as parasympatholytic, remember? That's because they stop the parasympathetic-like response.

01:51 So antimuscarinic drugs is another way of saying that, and so is muscarinic blocker .

01:56 Before we go on from here, make sure you understand why all of those terms are referring to similar responses.

02:07 Okay, so anticholinergics produces selective blockade of muscarinic receptors, not all the cholinergic receptor but they hit some of them.

02:16 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.

02:28 Atropine is a muscarinic antagonist medication and we use it for increasing the heart rate, bradycardia when the patient is symptomatic.

02:37 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.

02:45 or they're unconscious, that would be a time to give the medication.

02:48 And finally, mushroom poisoning is excessive amounts of muscarinic agonist exposure, and can be treated with a muscarinic antagonist like atropine.

03:00 Thanks for watching our video today and we hope you survive mushroom poisoning!