CHOLINERGIC DRUG Flashcards
(22 cards)
When does we use adrenaline and acetylcholine?
Adrenaline - during sympathetic (fight or flight)
Acetylcholine - during parasympathetic (rest and digest)
State the locations of cholinergic neurons.
- Basal forebrain
- Nucleus basalis
- Medial septal nucleus and nucleus of the diagonal band
- Pedunculopontine nucleus and laterodorsal tegmental nucleus
State the types of cholinergic receptors.
- Nicotinic acetylcholine receptors (Ionotropic)
2. Muscarinic acetylcholine receptors (Metabotropic) - G protein coupled
What is the fx of acetylcholinsterase?
Breaks ACh down into acetate and choline.
State 1 fx of acetylcholine.
Used at NMJ to cause muscle contraction
What is the subtypes of nicotinic receptors and where is the location of the subtypes?
- Nm - NMJ
- Nn
- Can be found in the peripheral:autonomic ganglia & adrenal medulla
- Can be found in the central: CNS
List the subtypes of muscarinic receptors and its location.
- M1
- CNS neurons
- Sympathetic postganglionic cell bodies - M2
- Myocardium
- Smooth muscled organs - M3
- Glands
- Smooth muscle
- Endothelium
- Eyes - M4
- CNS - M5
- CNS
In muscarinic agonist, which one will stimulate excitatory?
M1,M3,M5
In muscarinic agonist, which one will produce inhibitory effect?
M2, M4
Classify cholinergic drugs into direct and indirect acting drugs
Directly acting
- ACh
- Pilocorpine
- Bethanecol
- Methacoline
Indirectly acting
- Reversible: Neostigmine, edrophonium, physostigmine
- Irreversible: Organophosphate, malathion
State the therapeutic uses of pilocarpine
- Medical management of glaucoma
- Dry mouth treatment
- Sjogren’ syndrome - an autoimmune disease - body’s immune system attacks glands that secrete fluid including lacrimal and salivary glands
State the adverse effect of pilocarpine.
- Excessive sweating (diaphoresis)
- Excessive tearing
- Blurred vision
- Increased need to urinate (frequency)
- Bradycardia
State other therapeutic uses of cholinergic stimulants.
- Bethanicol - urinary bladder disorder
- Methacholine - diagnosis of bronchial hyperactivity
- Acetylcholine/ carbachol - miotic agents
What is the causes of muscarinic toxicity?
- Overdose of medications
- Mushroom poisoning
- Organophosphate poisoning
What is the sign and symptoms of muscarinic toxicity?
D- Diarrhoea
U- Urination
M- Miosis : contraction of the pupil of the eye.
B- Bradycardia : a slower than normal heart rate
B- Bronchospasm : a tightening of the muscles that line the airways (bronchi) in your lungs
E- Emesis : vomit
L- Lethargy : drowsiness
L- Lacrimation : abnormal or excessive secretion of tears due to local or systemic disease
S- Salivation/ seizure
What is treatment of muscarinic toxicity?
- Blockade of muscarinic activity with muscarinic cholinergic blockers such as atropine
- Reversal of acetylcholinesterase inhibition such as pralidoxime
What is the effect of muscarinic receptor in the eye?
- In the eye, the muscarinic receptor is M3 receptor. It is a Gq.
- In the eye, the M3 will causes the sphinter to contract.
- This will lead to miosis.
- M3 will also causes the ciliary muscle to contract
- Hence, it will accomodate near vision.
What is the mechanism of action of pilocarpine?
- Pilocarpine bind to muscarinic receptor.
- This will causes phospholipase C to be activated.
- The activation of phospholipase C will causes the PIP2 to cleave to IP3 and DAG.
- DAG undergoes phosphorylation and is catalysed by PKC.
- Hence, the channel for Ca+ is opened and this lead to muscle contraction d/t high amount of Ca+
List the effect of pilocarpine in the eye.
- Contraction of ciliary muscle
- Fixed near vision
- Lower the intraocular pressure
- Increase the glandular secretion
TRUE/FALSE
MANAGEMENT OF ORGANOPHOSPHATE POISONING INCLUDES:
A. ATROPINE TO COUNTERACT THE NICOTINIC RECEPTOR OVERSTIMULATION
B. PILOCARPINE TO THE MUSCARINIC RECEPTOR OVERSTIMULATION
C. PRALIDOXIME TO REGENERATE ACETYLCHOLINESTERASE.
D. EDROPHONIUM FOR THE DIAGNOSIS
E. SUCCINYLCHOLINE TO REDUCE SEIZURES
A. FALSE (THE AMOUNT OF ACETYLCHOLINE IS HIGH ATROPINE IS A CHOLINERGIC BLOCKER (ANTICHOLINERGIC) - REDUCE THE AMOUNT OF ACETYCHOLINE BUT IT BINDS TO THE MUSCARINIC RECEPTOR NOT NICOTINIC RECEPTOR)
B. FALSE (PILOCARPINE IS A CHOLINERGIC DRUG. IT WILL INCREASE THE AMOUNT OF ACETYLCHOLINE.)
C. TRUE (ATROPINE AND PRALIDOXIME IS CONSUMED DURING MUSCARINIC TOXICITY/ ORGANOPHOSPHATE POISONING)
D. FALSE (EDROPHONIUM IS USED TO DIAGNOSED MG AS IT IS AN ANTICHOLINESTERASE. IT WILL INCREASE THE AMOUNT OF ACETYLCHOLINE)
E. FALSE (SUCCINYLCHOLINE IS A DEPOLARISING MUSCLE RELAXANT.)
TRUE/FALSE
PILOCARPINE:
A. IS AN ANTICHOLINERGIC DRUG
B. MIOSIS
C. CYCLOPLEGIA
D. IS USED FOR THE TREATMENT OF GLAUCOMA
E. ANTAGONIST BY PHYSOSTIGMINE
A. FALSE (CHOLINERGIC DRUG. ANTICHOLINERGIC DRUG = ATROPINE)
B. TRUE (DECREASED THE INTRAOCULAR PRESSURE. SAME LIKE ANTICHOLINESTERASE)
C. FALSE (CYCLOSPASM. CYCLOPLEGIA = ATROPINE)
D. TRUE (AS IT CAN DECREASED THE INTRAOCULAR PRESSURE AND INCREASE THE LACRIMINAL SECRETION)
E. FALSE (PHYSOSTIGMINE IS AN ANTICHOLINESTERASE -> INCREASE OF ACETYLCHOLINE -> SAME F(X) AS PILOCARPINE)
TRUE/FALSE
WHICH OF THE FOLLOWING DRUGS AND THEIR THERAPEUTIC USES ARE CORRECTLY MATCHED?
A. NEOSTIGMINE: MG
B. ATROPINE: GLAUCOMA
C. IPRATROPIUM BROMIDE: BRONCHIAL ASTHMA
D. SCOPOLAMINE: MOTION SICKNESS
E. PILOCARPINE: ORGANOPHOSPHATE POISONING
A. TRUE (NEOSTIGMINE IS AN ANTICHOLINESTERASE. IT WILL INCREASE THE ACETYLCHOLINE)
B. FALSE (ATROPINE WILL INCREASE THE INTRAOCULAR PRESSURE. PILOCARPINE AND NEOSTIGMINE CAN DECREASE THE INTRAOCULAR PRESSURE -> TREAT GLAUCOMA)
C. TRUE (SAME GRP AS ATROPINE - ANTICHOLINERGIC -> INCREASE THE AMOUNT OF ACETYLCHOLINE)
D. TRUE
E. FALSE (PILOCARPINE IS THE CAUSED OF ORGANOPHOSPHATE POISONING)
