Cholinergics

Question 1

What is acetylcholinesterase?

Answer 1

An enzyme that breaks down acetylcholine

Question 2

What is miosis?

Answer 2

Very constricted pupils

Question 3

What is a cholinergic agonist?

Answer 3

Drugs that mimic the effects of the neurotransmitter acetylcholine (and therefore the parasympathetic nervous system)
agonist = to stimulate/increase the effects

Not limited to a specific site –> many undesired systemic effects

Work either directly or indirectly on ACh receptors

(AKA parasympathomimetic)

Question 4

What is Myasthenia gravis?

Answer 4

• A chronic autoimmune disorder affecting the muscles
• Patients make antibodies to ACh receptors, causes destruction of them
• Progressive weakness and lack of muscle control with periodic acute episodes

Question 5

What is Alzheimer’s Disease?

Answer 5

• A progressive disease that causes neural degeneration in the cortex
• Leads to marked loss of memory, decreased ability to perform ADLs
• Believe there is a progressive loss of ACh producing neurons

Question 6

What are the effects of the parasympathetic nervous system?

Answer 6

REST AND DIGEST
* Pupil constriction
* ⬆️ salivation
* ⬆️ respiratory secretions
* ⬆️ peristalsis
* Vasodilation (in most blood vessels)
* Bronchoconstriction
* ⬇️ heart rate
* ⬇️ blood pressure
* Bile release
* Urination

Question 7

Lifespan Considerations of Cholinergic Drugs
In Children

Answer 7

• Increased risk of adverse effects
• Dosages should be based off weight

Question 8

Lifespan Considerations of Cholinergic Drugs
In Adults

Answer 8

• Caution against driving while on medication
• No studies on safety during pregnancy/lactation
• Use alternative method to breastfeeding

Question 9

Lifespan Considerations of Cholinergic Drugs
In Older Adults

Answer 9

• More likely to have adverse effects
• More likely to have toxic levels
• Start low and go slow
• Institute safety precautions

Question 10

Direct Acting Cholinergic Agonists
Mechanism of Action

Answer 10

• Mimics acetylcholine at the receptor sites (muscarinic or nicotinic) on the surfaces of the target cells of the postganglionic cholinergic nerves
• Causes an increased stimulation of the cholinergic receptor

Question 11

Direct-Acting Cholinergic Agonists: 🍄Muscarinic
Indications

Answer 11

• Urinary Retention (Bethanechol)
• To induce miosis (carbachol)
• Treat dry mouth (cevimeline & pilocarpine)

Question 12

Direct-Acting Cholinergic Agonists: 🍄Muscarinic
Drug Names

Answer 12

• Bethanechol (urinary retention)
• Carbachol (to induce miosis)
• Cevimeline (treats dry mouth)
• Pilocarpine (treats dry mouth)

Question 13

Direct-Acting Cholinergic Agonists: 🍄Muscarinic
Contraindications

Answer 13

Absolute:
* Allergy
* Any condition that would be exacerbated by parasympathetic effects: Bradycardia, hypotension
* Peptic Ulcer Disease, GI obstruction or recent GI surgery
* Asthma (can cause bronchoconstriction)
* Bladder obstruction
* Epilepsy and parkinsonism (can worsen)

Caution:
* Pregancy and lactation

Question 14

Direct-Acting Cholinergic Agonists: 🍄 Muscarinic
Adverse Effects

Answer 14

💩 Diarrhea, involuntary defecation, cramps
🤮 Nausea, vomiting, increased salivation
💓 Bradycardia, heart block, hypotension
🫣 Urinary urgency
💦😳 Flushing or increased sweating

Question 15

Direct-Acting Cholinergic Agonists: 🍄Muscarinic
Drug Interactions

Answer 15

Acetylcholinesterase Inhibitors

(Indirect-Acting Cholinergic Agonists)

Can lead to a cholinergic crisis!

Question 16

Direct-Acting Cholinergic Agonists: 🍄Muscarinic
Assessment

Answer 16

History:
* Contraindications & Cautions

Physical:
* Vitals
* Lung sounds
* Bowel sounds
* Bladder distention
* Input & Output

Question 17

Direct-Acting Cholinergic Agonists: 🍄Muscarinic
Nursing Diagnoses

Answer 17

• Impaired Comfort (r/t GI effects)
• Altered cardiac output (r/t CV effects)
• Impaired urinary elimination (r/t GU effects)
• Injury risk (r/t blurry vision, changes in visual acuity)
• Diarrhea (r/t GI effects)
• Knowledge Deficit

Question 18

Direct-Acting Cholinergic Agonists: 🍄Muscarinic
Implementation/Patient Teaching

Answer 18

• Ensure proper administration of opthalmic preparations
• Administer oral drugs on an empty stomach
• Monitor response closely
• Provide safety precautions (fall risk) if pt experiences poor visual acuity
• Monitor urinary output

Question 19

Direct-Acting Cholinergic Agonists: 🚬 Nicotinic
Indications

Answer 19

Smoking cessation

(Work mostly in CNS - quicker acting than muscarinc receptor agonists)

Question 20

Direct-Acting Cholinergic Agonists: 🚬 Nicotinic
Drug Names

Answer 20

• Bupropion (weakly inhibits neuronal reuptake of NE and Dopamine)
• Varenicline (acts as nicotine receptor partial agonist)
• Nicotine (replacement therapy)

Question 21

Direct-Acting Cholinergic Agonists: 🚬 Nicotinic
Contraindications

Answer 21

Absolute:
* Allergy
* Seizure disorder (Bupropion) reduces seizure threshold

Caution:
* Pregnancy and lactation

Question 22

Direct-Acting Cholinergic Agonists: 🚬 Nicotinic
Adverse Effects

Answer 22

💓 Tachycardia, hypertension (due to too much increased fluid)
🧠 Seizures, neuropyschiatric adv. effects, dizziness, strange dreams
🤢Nausea and dry mouth
😡Skin rash (r/t cholinergic urticaria)

MORE potential for CNS effects than muscarinic agonists

Question 23

Direct-Acting Cholinergic Agonists: 🚬 Nicotinic
Drug Interactions

Answer 23

TOO MANY to name

Question 24

Direct-Acting Cholinergic Agonists: 🚬 Nicotinic
Assessment

Answer 24

History:
* Contraindications & Cautions
* Amount of tobacco use
* Sleep patterns
* suicidal thoughts and behaviors

Physical:
* Lung sounds
* Heart Sounds
* Vital Signs
* ECG
* mood, affect

Question 25

**Direct-Acting Cholinergic Agonists: 🚬 Nicotinic** Nursing Diagnoses

Answer 25

* Impaired comfort *(r/t GI effects)* * Altered cardiac output *(r/t CV effects)* * Injury risk *(r/t seizures or neurpsychiatric side effects)* * Knowledge deficit

Question 26

**Direct-Acting Cholinergic Agonists: 🚬 Nicotinic** Implementation/Patient Teaching

Answer 26

* ensure proper administration of nicotine replacement preparations * Check for med interactions * May be taken with or without food * Dose may be adjusted * Safety precautions for neuropsychiatric effects or seizure activity * Correct # of patches changed at the right times * Take OFF old patches before applying new one * Report changes in CNS effects

Question 27

**Indirect-Acting Cholinergic Agonists** Indications

Answer 27

* Myasthenia gravis * Alzheimer's Disease

Question 28

**Indirect-Acting Cholinergic Agonists** Drugs to treat Myasthenia gravis

Answer 28

* **Neostigmine** *(strong influence at neuromuscular junction)* * **Pyridostigmine** *(longer duration of action than neostigmine)* * **Edrophonium** *(diagnostic agent.... no longer used - too many false positives)*

Question 29

**Indirect-Acting Cholinergic Agonists** Adverse Effects

Answer 29

💓 **Brady**cardia, **hypo**tension 💩 Increased GI activity and secretions 💛 Increased bladder tone = overactive bladder 🟢 Relaxation of GI and Genitourinary sphincters 🫁 Broncho**constriction** 👁️ Pupil **constriction**

Question 30

**Indirect-Acting Cholinergic Agonists** Drug Interactions

Answer 30

* NSAIDs *(cause GI erosions)* * Cholinergic Drugs *(can cause Increased secretions)* Combining the drugs can lead to a Gastric Bleed

Question 31

**Indirect-Acting Cholinergic Agonists** Drugs used to treat Alzheimer's Disease

Answer 31

* **Galantamine** *(avail. in solution for easy swallowing)* * **Rivastigmine** *(avail. in solution for easy swallowing)* * **Donepezil** *(once a day dosing, rapidly dissolving tablet)*

Question 32

How does nerve gas affect Cholinergic receptors?

Answer 32

* **Permanently** and irreversibly binds to **Acetylcholinesterase** --> leads to significant increase in Acetylcholine * Treatment: **Atropine and Pralidoxime *(anticholinergics)***

Question 33

**Indirect-Acting Cholinergic Agonists** Assessment

Answer 33

**History:** * Contraindications & cautions **Physical:** * Neuro: Orientation, affect, reflexes, ability to perform ADLs * Vital Signs * ECG * Urinary output **Labs:** * Renal and Liver function tests

Question 34

**Indirect-Acting Cholinergic Agonists** Nursing Diagnoses

Answer 34

* Altered thought processes *(r/t CNS effects)* * Impaired comfort *(r/t GI effects)* * Decreased cardiac output *(r/t blood pressure changes, arrhythmias, and vasodilation)* * Injury risk *(r/t CNS effects)* * Diarrhea *(r/t GI stimulatory effects)* * Knowledge deficit

Question 35

**Indirect-Acting Cholinergic Agonists** Implementation

Answer 35

* If given via IV, go slowly * Maintain atropine sulfate on standby for cholinergic crisis * Discontinue drug if: excessive salivation, diarrhea, emesis, or frequent urination * Oral drug with meals * If going into surgery, notify surgeon that they are on cholinergic drugs * Monitor Alzheimer's pts for progress * Arrange for supportive care and comfort measures