Cholinergics Flashcards
What are the main clinical uses of Pilocarpine
alkaloid non-selective muscarinic acetylcholine receptor agonist
- narrow and wide angle glaucoma therapy
- Dry mouth due to autoimmune disease of exocrine glands/radiation therapy of head and neck cancer/anticholinergic medication
Side effects of Pilocarpine
Adverse side effects (due to overstimulation)
- Topical ophthalmic administration → eye stinging and irritation but has minimal systemic absorption
- oral administration → sweating, blurred vision and other cholinergic adverse effects; worsens asthma and COPD
What are the main clinical uses of Bethanechol
Choline ester muscarinic acetylcholine receptor agonist
- M3 receptor activation
Uses:
- Treatment of gastric atony (loss of muscle strength) after vagotomy
- Treatment of urinary retention in the absence of obstruction
Bethanechol contraindication
Asthma
Name some examples of direct cholinergic drugs:
Muscarinic:
- Pilocarpine (alkaloid)
- Bethanechol (Choline ester)
Nicotinic:
- Nicotine (Alkaloid)
- Verenicline (Partial agonist)
Both:
Acetycholine (Choline ester)
Cholinergic anticholinergic side effects always have to do with
bladder, GIT, pupils
common adverse effects of cholinergic agonists
- Diarrhoea
- Sweating (diaphoresis)
- Miosis
- Nausea
- Urinary urgency
Contraindicated in asthma
Nicotine uses, ADRs
Use: aid to smoking cessation
ADRs:
- Dependence due to activation of brain dopaminergic reward pathways
- Low dose (like in cigarettes): increased HR, BP, RR; decreased appetite
- High dose: medullary depression, bradycardia and neuromuscular blockade
Nicotine is
Nicotine is a nicotinic acetylcholine receptor agonist (both in brain and neuromuscular)
It directly activates nicotinic receptor
And indirectly activates muscurinic receptor
Name the three types of indirect Anticholinergic Drugs
- Ganglionic blockers
- - Eg: Nicotine @ high dose
2a. Non-Depolarizing NeuroMuscular Blocking Agents (Non-Depolarizing NMBAs)
- - Eg: Pancuronium
2b. Depolarizing NeuroMuscular Blocking Agents (Depolarizing NMBAs)
- - Eg. Succinylcholine
- Presynaptic toxin (Inhibitor of vesicular exocytosis)
- -Eg. Botulinum toxin (AKA BOTOX)
MOA of nicotine
Depolarize the cell so much that there is no more gradient for sodium to flow. no more action potential to fire
5 examples of direct anticholinergic drugs:
They are generally all contraindicated for?
Atropine Benzatropine Scopolamine Ipratropium Oxybutynin
Narrow angle glaucoma
In organophosphate poisoning (very long acting anticholinesterases/AchE inhibitors), the following clinical symptoms can be present: (SLUD)
Think about what happens when you block Ach from breaking down for a LONG time –> cholinergic side effects. Think bladder, pupil, GIT.
- Salivation
- Lacrimation
- Urination
- Defecatino
In organophosphate poisoning (very long acting anticholinesterases/AchE inhibitors), the following clinical symptoms can be present: (SLUD)
Think about what happens when you block Ach from breaking down for a LONG time –> cholinergic side effects. Think bladder, pupil, GIT.
- Salivation
- Lacrimation
- Urination
- Defecatino
Treatment of organophosphate poisoning
- Pralidoxime (cholinesterase regenerator) BEFORE “aging”
2. Atropine (muscarinic receptor blocker) for symptomatic treatment
