Cholinergics/Cholinergics Blockers Flashcards
What type of receptor does atropine act as a competitive antagonist for?
Muscarinic receptors (M1, M2, M3)
Atropine blocks the action of acetylcholine at these receptors.
What is the mechanism of action for atropine?
Inhibits parasympathetic activity by blocking acetylcholine action
This leads to increased heart rate and reduced secretions.
List three indications for the use of atropine.
- Bradycardia
- Preoperative use
- Organophosphate poisoning
Atropine is also used in ophthalmic procedures to dilate pupils.
What are common adverse effects of atropine?
- Dry mouth
- Blurred vision
- Tachycardia
- Urinary retention
- Constipation
- Confusion and delirium
- Hot, dry skin
These effects are particularly pronounced in elderly patients.
True or False: Atropine is contraindicated in narrow-angle glaucoma.
True
Its effect on pupil dilation can increase intraocular pressure.
What is the mechanism of action of phentolamine?
its ability to competitively block alpha-adrenergic receptors, leading to vasodilation and a reduction in blood pressure
List two indications for phentolamine.
- Pheochromocytoma
- Hypertensive crisis
It is also used for the reversal of local anesthesia effects.
What are common adverse effects of phentolamine?
- Hypotension
- Tachycardia
- Nasal congestion
- Dizziness
- Arrhythmias
- Chest pain
These effects are primarily due to vasodilation.
What is the primary mechanism of action of pyridostigmine?
Acetylcholinesterase inhibitor
It increases acetylcholine levels at the neuromuscular junction.
List three indications for the use of pyridostigmine.
- Myasthenia gravis
- Postoperative ileus
- Reversal of non-depolarizing neuromuscular blockers
It enhances neuromuscular transmission.
What are common adverse effects of pyridostigmine?
- Muscarinic effects
- Bradycardia
- Muscle cramps
- Weakness
- Respiratory distress
These effects can indicate cholinergic toxicity.
What is the mechanism of action of bethanechol?
Direct-acting cholinergic agonist
It stimulates muscarinic receptors in the bladder.
List two indications for the use of bethanechol.
- Urinary retention
- Neurogenic bladder
It promotes bladder emptying.
What are common adverse effects of bethanechol?
- Diarrhea
- Abdominal cramping
- Excessive salivation
- Flushing
- Bradycardia
- Hypotension
- Bronchospasm
Caution is needed in patients with asthma or COPD.
What is the mechanism of action of oxybutynin?
Anticholinergic that blocks muscarinic receptors
It reduces bladder spasms and urinary urgency.
List two indications for the use of oxybutynin.
- Overactive bladder syndrome
- Neurogenic bladder
It helps manage urinary urgency and frequency.
What are common adverse effects of oxybutynin?
- Dry mouth
- Constipation
- Blurred vision
- Dizziness
- Urinary retention
- Confusion and memory issues
These effects are especially concerning in elderly patients.
What is the mechanism of action of donepezil?
Acetylcholinesterase inhibitor
It increases acetylcholine levels in the brain.
What is donepezil primarily used to treat?
Alzheimer’s disease
It is used for mild to moderate Alzheimer’s to improve cognitive function.
What is the classification of Atropine?
Anticholinergic (Parasympatholytic), Muscarinic receptor antagonist
What are the contraindications for Atropine?
Narrow-angle glaucoma, Myasthenia gravis, Tachyarrhythmias, Intestinal or urinary tract obstruction, Hypersensitivity
What is the classification of Phentolamine?
Alpha-adrenergic antagonist (Alpha blocker), Non-selective alpha-1 and alpha-2 blocker
What are the contraindications for Phentolamine?
History of coronary artery disease (CAD), Hypersensitivity, Pheochromocytoma (untreated), Severe hypotension
What is the classification of Pyridostigmine?
Cholinesterase inhibitor (Indirect-acting cholinergic agonist), Acetylcholinesterase inhibitor
