Term
| What drug is slowly metabolized by AChe, but not metabolized by butyrylcholinesterase? |
|
Definition
|
|
Term
| What are methacholine's 2 therapeutic uses? |
|
Definition
| It's diagnostic for bronchial asthma and peripheral vascular spasms. |
|
|
Term
| Why is ACh typically not used as a drug? |
|
Definition
| B/c it gets degraded too quickly |
|
|
Term
| Where is ACh found? Butyrylcholinesterase? |
|
Definition
| ACh is found in all synapses. Butyrylcholinesterase is found in the blood. |
|
|
Term
T or F Methycholine will not stimulate N receptors |
|
Definition
|
|
Term
T or F Methylcholine will only stimulate M1, M2, and M3 receptors |
|
Definition
| False, it will stimulate all M receptors |
|
|
Term
Is bethanechol susceptible to hydrolysis by AChe? Butyrylcholinesterase? |
|
Definition
|
|
Term
| Where are bethanechol's sites of action? |
|
Definition
| At all M receptors, especially in the GI tract and the urinary bladder. |
|
|
Term
| Which is most likely to have the longest half life: ACh, methacholine, or bethanechol. |
|
Definition
|
|
Term
| What are bethanechol's primary therapeutic uses? |
|
Definition
| Postoperative abdominal distension and urinary retention. |
|
|
Term
| Which cholinomimetic is a alkaloid, non-choline ester, and tertiary amine? Could this drug cross the BBB? |
|
Definition
|
|
Term
| Where is pilocarpine's site of action? |
|
Definition
|
|
Term
| What is pilocarpine's main therapeutic use? How does it work? |
|
Definition
| Glaucoma; like ACh, pilocarpine stimulates M3 receptors on the iris sphincter muscle. This causes contraction of the sphincter muscle, which increases the angle b/w the iris and the cornea so the aqueous humor can drain. |
|
|
Term
| What are 3 contraindications for direct acting cholinomimetics? |
|
Definition
| Bronchial asthma, GI ulcer, &/or hyperthyroidism |
|
|
Term
| What are 6 adverse effects caused by direct acting cholinomimetics? |
|
Definition
Think "HIS DDS" Hypotension Intestinal cramps, Salivation Dyspnea Diaphoresis Spasm of accomodation (the constant stimulation of the ciliary muscle would make it hard to see distant objects) |
|
|
Term
| What type of cholinomimetic is physostigmine? |
|
Definition
| Reversible, indirect acting cholinesterase inhibitor |
|
|
Term
| Where is physostigmine's site of action? |
|
Definition
| At all cholinergic synapses |
|
|
Term
Out of the following drugs, which do not have a charge? Methacholine Bethanechol Pilocarpine Physostigmine Neostigmine DFP Echothiophate Atropine Hexamethonium Mecamylamine |
|
Definition
| pilocarpine, physostigmine, DFP, and Mecamylamine |
|
|
Term
| What is physostigmine's therapeutic use? How does it work? |
|
Definition
| It's a miotic for pts w/ glaucoma. It binds to AChe, preventing the degradation of ACh. The ACh then builds up and stimulates the iris sphincter muscle. |
|
|
Term
| What type of drug is neostigmine? What is its therapeutic use? |
|
Definition
| Neostigmine is a mixed acting cholinomimetic. It's therapeutic use is myasthenia gravis (severe muscle weakness. Myasthenia gravis is an autoimmune disorder that occurs when a person's own Abs attack their N receptors. The neostigmine can act directly at the neuromuscular junction to stimulate the N receptors, and thus, muscle movement. |
|
|
Term
| What happens if too much neostigmine is used? What drug is a good diagnostic of how much neostigmine has been used? How is this drug a good diagnostic? |
|
Definition
If too much neostigmine is used, it can block the N receptors, which would cause paralysis. Edrophonium can be given in conjunction w/ neostigmine to make sure too much neostigmine has not been given. If edrophonium increases muscle tone, you need more neostigmine. If edrophonium decreases muscle tone, you need less neostigmine. |
|
|
Term
| What syndrome is treated by edrophonium? How does edrophonium work on this syndrome? |
|
Definition
| Paroxysmal Atrial Tachycardia (PAT); PAT is a syndrome where the atrial heart continually fluctuates until it begins to wane. Edrophonium can bind to the AChe, so that more ACh can build up and bind to the M2 receptors in the SA node to decrease the frequency of the HR. |
|
|
Term
| Name 5 irreversible AChe inhibitors? How do they work? |
|
Definition
| DFP, Echothiophate, tabun, sarin, & soman. They phosphorylate the esteratic site of cholinesterase. |
|
|
Term
| What type of drugs function as insecticides? |
|
Definition
| Irreversible cholinesterase inhibitors |
|
|
Term
| What 3 drugs are used as chemical warfare agents? |
|
Definition
|
|
Term
What are DFP's sites of action? What are echothiophate's sites of action? |
|
Definition
DFP acts indirectly at all cholinergic synapses. Echothiophate acts at all peripheral cholinergic synapses. |
|
|
Term
What is DFP's therapeutic use? What is echothiophate's therapeutic use? |
|
Definition
| They are both used to cause miosis. |
|
|
Term
What are 3 possible adverse effects of cholinesterase inhibitors? |
|
Definition
| cholinergic overstimulation (could lead to paralysis of respiratory muscles), cataracts, and chronic neurotoxicity (could cause anything from weakness of legs to flaccid paralysis). |
|
|
Term
| What are 2 antidotes for cholinesterase inhibition? How do they work? |
|
Definition
| Atropine and Pralidoxime; Atropine blocks the M receptors to prevent overstimulation. Pralidoxime removes the phosphorous from the cholinesterase. The pralidoxime has to be given shortly after exposure in order to work. |
|
|
Term
| What is atropine's order of blockade: |
|
Definition
a) salivary, bronchial, and sweat glands b) iris, ciliary muscle, & vagus to heart c) bladder & GI smooth muscle d) gastric acid secretion |
|
|
Term
|
Definition
| It is used for GI ulcers. It is an antagonist that is selective for M1 receptors. Therefore, it is used to prevent gastric acid secretion. |
|
|
Term
|
Definition
| It is a muscarinic receptor antagonist used for bronchial asthma. |
|
|
Term
How could a muscarinic receptor antagonist cause heat stroke? |
|
Definition
| ACh is responsible for sweating. If M receptors are blocked, there will be no sweating. If the temperature is hot and the body cannot sweat to get rid of the heat, the core temperature can get really high and cause heat stroke. |
|
|
Term
Name 2 contraindications for muscarinic receptor antagonists. Explain. |
|
Definition
| People w/ narrow angle glaucoma shouldn't be given these drugs. They need ACh to move their iris away from their cornea so they can drain their aqueous humor. Obviously, if the iris has already been removed, this isn't a problem. Also, people who have chronic lung disease shouldn't be given these drugs, b/c these drugs will cause inspissation (excess drying). These people need ACh to bind w/ their M receptors to secrete mucous to remove unwanted material from their airways. |
|
|
Term
|
Definition
| It blocks exocytosis of ACh. |
|
|
Term
| How does hemicholinum work? |
|
Definition
| It prevents ACh synthesis by blocking choline uptake. |
|
|
Term
|
Definition
| It blocks the active transport mechanism required for ACh to enter the synaptic vesicle. |
|
|
