Cholinergic Drugs Flashcards
Types of cholinergic receptors and where they are found
Nicotinic 1. N1 = skeletal muscle 2. N2 = ganglia and CNS Muscuranic M1 = Stomach and CNS M2 = Heart, CNS, Gall bladder, Genitals (remember using HCG) M3 = Lungs, glands, GIT, cilliary body, iris, CNS M4, M5 = CNS
Post synaptic receptor stimulation of eccrine sweat glands and receptor involved
M3 receptor
Acetylcholine is the neurotransmitter used
What does any cholinergic drug that crosses the BBB do
Binds to M1 receptor in the brain and causes Nausea and Vomitting
Common adverse effects of cholinergic agonist and contraindications
Adverse effects
- Nausea
- Miosis
- Urinary urgency
- Diarrhoea
- Sweating
Contraindications
- Asthma
- Peptic ulcer
Names of direct cholinergic agonists
- Pilocarpine (muscuranic agonist, alkaloid)
- Bethanachol (muscuranic agonist, carbamate choline ester)
- Carbachol (muscuranic agonist, carbamate choline ester)
- Nicotine (nicotinic agonist, alkaloid)
- Vareniciline (nicotinic agonist, alkaloid)
What type of ammonium is ACh and does it cross BBB
It is a quatenary ammonium
Does not cross BBB
What is the benefit of Carbamate choline esters
Carbamate choline esters are not broken down by endogenous choline esterases but are broken down by other enzymes as such their half life is longer
What is Pilocarpine and what is it used for and its adverse effects
Alkaloid non-selective muscuranic receptor agonist
Used in treatment of glaucoma and dry mouth
Side effects : Nausea, blurred vision, urinary urgency, diarrhoea, sweating
Contraindicated in patients with ASTHMA and COPD
Bathenachol
Receptor, function, used to treat what, side effects and contraindications
Quaternary choline ester
Does not cross BBB
Increases detrusor tone and decrease outlet resistance of internal sphincter
Used to treat : Gastric atony and urinary retention
Side effects : Nausea, blurred vision, urinary urgency, diarrhoea, sweating
Contraindications: Asthma and COPD
Nicotine
Receptor, Function, what its used to treat, adverse effects
Binds to both neuromuscular receptor and neuronal nicotinic receptor
Low dose :
Causes skeletal muscle fasiculations, low dose causes ganglionis activation causing adrenaline release which causes increase in heart rate and contractility. Nicotine also causes increase in GI motility and secretion
High dose:
Causes depolarising blockade, medullary depression, bradycardia
Variniciline
Receptor and use
Partial nicotinic agonist, highly effective in smoking cessation
Indirect cholinergic drugs
Reversable and irreversible category
Reversible category :
- Physostigmine/donapazil
- Neostigmine
- Pyridostigmine
Irreversible category:
- Sarin
- Parathion
- Malathion
Donepazil/Physostigmine
- crosses BBB
- used to treat alzheimer’s disease
- Side effects : Nausea, vomiting, blurred vision, urinary urgency, diarrhoea, sweating
Neostigmine
- Does not cross BBB
- Used to reverse non-depolarising blockade (i.e. coming out of anaesthesia) and myasthenia gravis
- Side effects : Nausea, blurred vision, urinary urgency, diarrhoea, sweating
Irreversible choline esterase inhibitors
Sarin, Parathion, Malathion
Sarin, parathion, malathion
Organophosphate agent
Suicide inhibitor of acetylcholine esterase
Clinical presentation : Salivation, Lacrimation, Urination, Defecation (SLUD), miosis, bradycardia, hypotension
Antidote = Pralidoxime (acetyl choline esterase regenerator) and Atropine (muscuramic antagonist)
Pralidoxime
Acetylcholine esterase regenerator
Higher affinity for phosphate than acetylcholine
Used to treat organophosphate poisoning
Only effective in inhibition of AChE via organophosphate not if it is inhibited in other mechanisms such as carbamylation via neostigmine
Direct anticholinergic drugs
- Atropine
- Benzatropine
- Scopolamine
- Ipratropium
- Oxybutynin
- NonDepolarising NeuroMuscular Blocking Agent (NMBA)
- Pancuronium
- Rocuronium
- Atracurium
- Tubocurarine
Benzatropine
Non-selective muscuranic acetylcholine receptor antagonist
Crosses BBB
Used to treat Parkinson’s disease
Side effects : Dry mouth, Blur vision, Urinary retention, Glaucoma, Sedation (use D-BUGS to remember)
Contraindicated in : Narrow angle glaucoma
Atropine
Non-selective muscuranic acetylcholine receptor antagonist
Increases heart rate
Used to treat : 1. Overdose of AChE inhibitor and organophosphate poisoning
Side effects : Superficial vasodilation, Blur vision, decreased secretion, hyperthermia, delerium and hallucinations
Contraindications : Narrow angle glaucoma
Use red as a beet, blind as a bat, dry as a bone, hot as a hare, mad as a hatter to remember
Scopolamine
Non-selective muscuranic acetylcholine receptor antagonist
Used to treat motion sickness
Side effects : Dry mouth, Blur vision, Urinary retention, Glaucoma, Sedation (use D-BUGS to remember)
Contraindicated in narrow angle glaucoma
Ipratropium
- Non-selective muscuranic acetylcholine receptor antagonist
- reduce bronchoconstriction
- used to treat Asthma and COPD
- Side effects : Dry mouth, Blur vision, Urinary retention, Glaucoma, Sedation (use D-BUGS to remember)
Oxybutynin
Relax smooth muscle walls, increase sphincter tone
Used to treat Urinary incontinance
Contraindicated in : pyloric obstruction and bladder retention
Non depolarising NeuroMuscular Blocking Agents
Pancuronium
Rocuronium
Atrocurorium
Tubocurarine
Competitively block nicotinic acetylcholine receptor
Causes paralysis of skeletal muscle
Side effects : Histamine release at higher doses causeing flushing, edema and hypotension
Indirect anticholinergic drugs
- High dose nicotine
- Succinylcholine
- Botulinium Toxin
Clinical uses and side effects of BOTOX
Clinical uses
- Blepharospasm (excessive blinking)
- Strabismus (excessive squinting)
- Cervical dystonia
- Migraine
- Upper limb spasticity
- Cosmetic
Side effects : paralysis of wrong muscle group and allergic reaction
