Agonists & Antagonists Flashcards
Which is more sensitive to agonists, muscarinic or nicotine?
Muscarinic
Direct acting ACh agonists
ACh
Carbachol
Bethanechol
Pilocarpine
Therapeutic uses of ACh agonists
Glaucoma
Intraocular pressure in surgery
Treat xerostomia
Increase bladder tone and motility, also GIT motility
Acetylcholine is used for treatment of:
Myasthenia gravis
Alzheimer’s disease
Reverse the action of muscle relaxants
Ocular side effects of acetylcholine
Corneal swelling
Corneal clouding
Corneal decomposition
Systemic side effects of acetylcholine
sweating
difficulty in breathing
hypotension
flushing
slow heart rate
Carbachol therapeutic uses
- Treatment of glaucoma
- Used to constrict the pupils during cataract surgery.
Therapeutic uses of bethanechol
- Increases tone and motility of bladder and GI tract
- Relaxes sphincters in bladder and GI tract, allowing them to empty
Therapeutic uses of pilocarpine
- Totreat dry mouth caused by radiotherapy in people with head and neck cancerand to treat dry mouth in people with Sjögren’s syndrome
- Miotics to treat glaucoma byallowing excess fluid to drain from the eye.
Indirect acting agonists
Edrophonium
Physostigmine
Neostigmine
Echothiophate
General uses of indirect acting agonists
- Cause skeletal muscle contractions; hence, treatment ofmyasthenia gravis
- Used to reverse anticholinergic poisoning (antidote)
Therapeutic uses of donezepil
- Used in the treatment of mild to moderate Alzheimer’s disease.
- Helps to increase memory and learning capabilities
Side effects of indirect acting agonists
Bradycardia
Hypotension
Cconduction abnormalities
Headache
Dizziness
Loss of binocular accommodation
Which drugs are known to antagonize cholinergic agents, resulting in decreased responses apart from general antagonists?
Antihistamines
Depending on the type of receptor to act on, cholinergic antagonists are either classified as
muscarinic antagonists or nicotinic antagonists.