Cholinergic Agents & Blockers – Exam Review Flashcards

Fifty Question-and-Answer style flashcards covering direct-acting cholinomimetic agents, cholinesterase inhibitors, parasympathetic blockers, nicotinic antagonists, and neuromuscular blockers as outlined in the lecture notes.

What is the primary surgical use of acetylcholine given its very short duration of action?

To produce rapid miosis during cataract surgery.

Which synthetic choline ester selectively activates muscarinic receptors to stimulate bladder or GI muscle with minimal cardiovascular effect?

Bethanechol.

For which urinary condition is bethanechol commonly prescribed?

Non-obstructive neurogenic urinary retention (post-operative or postpartum).

Which direct-acting cholinergic agonist is used in ophthalmic surgery but is no longer first-line for open-angle glaucoma?

Carbachol.

Which mushroom-derived alkaloid acts as a cholinomimetic poison with no therapeutic use?

Muscarine.

Which alkaloid from Nicotiana plants is formulated as gums and patches for smoking deterrence?

Nicotine.

Name the tertiary amine alkaloid that serves as second-line therapy for glaucoma and treats Sjögren’s syndrome.

Pilocarpine.

Which synthetic muscarinic agonist selectively targets M3 receptors to treat Sjögren’s syndrome?

Cevimeline.

What is the mechanism of action of varenicline used in smoking cessation?

Partial agonist at α4β2 nicotinic receptors.

What black box warning accompanies varenicline therapy?

Risk of serious neuropsychiatric effects (mood changes, erratic behavior, suicidal ideation).

Which short-acting reversible cholinesterase inhibitor is used to diagnose myasthenia gravis?

Edrophonium.

Why can physostigmine cross the blood–brain barrier whereas neostigmine cannot?

Physostigmine is a tertiary amine (lipophilic); neostigmine is a quaternary amine (polar).

Besides glaucoma, physostigmine is the antidote for toxicity produced by which drug?

Atropine poisoning.

Name the two quaternary amine cholinesterase inhibitors commonly used to treat myasthenia gravis.

Neostigmine and Pyridostigmine.

List two postoperative conditions, other than myasthenia gravis, treated with neostigmine or pyridostigmine.

Post-operative ileus and postoperative urinary retention.

Which irreversible organophosphate cholinesterase inhibitor may be used in chronic, refractory glaucoma?

Echothiophate (or Isoflurophate).

Which organophosphate pesticide is also applied topically to eradicate head lice?

Malathion.

Soman and sarin belong to which class of toxic compounds?

Nerve gases (chemical warfare agents).

Which centrally acting cholinesterase inhibitor is approved for all stages of Alzheimer’s disease?

Donepezil.

For which stages of Alzheimer’s disease are galantamine and rivastigmine indicated?

Mild to moderate stages.

From which plant is atropine derived and what is its pharmacologic class?

Atropa belladonna; non-selective muscarinic receptor antagonist.

What drug combination is recommended for treating organophosphate poisoning?

Atropine together with pralidoxime.

Which muscarinic blocker is specifically employed to prevent motion sickness?

Scopolamine (hyoscine).

Name the inhaled muscarinic antagonists used as bronchodilators in COPD.

Ipratropium and Tiotropium.

Which anticholinergic drug treats irritable bowel syndrome by reducing intestinal hypermotility?

Dicyclomine.

Identify four synthetic muscarinic antagonists prescribed for overactive bladder.

Oxybutynin, Trospium, Darifenacin, Tolterodine.

What is the primary pre-operative use of glycopyrrolate?

Reduction of salivary secretions.

Mecamylamine blocks which type of cholinergic receptor and is reserved for which emergency condition?

Ganglionic nicotinic receptors; hypertensive crisis/malignant hypertension.

Non-depolarizing neuromuscular blockers ending in “-curium” belong to which chemical subclass?

Isoquinoline derivatives.

Which toxic metabolite produced by atracurium can provoke seizures?

Laudanosine.

What agent is typically administered to reverse atracurium-induced neuromuscular blockade?

Neostigmine.

Why is cisatracurium often preferred over atracurium?

It produces less laudanosine and therefore lower seizure risk.

Which classic non-depolarizing blocker causes marked histamine release leading to bronchospasm and tachycardia?

Tubocurarine.

What is the main route of elimination for steroid-based neuromuscular blockers like rocuronium?

Metabolism and elimination by plasma esterases.

Describe Hofmann elimination relevant to atracurium and cisatracurium.

Spontaneous degradation of the drug dependent on pH and temperature.

How does increasing pH and temperature influence Hofmann elimination of atracurium?

It accelerates the elimination process.

Succinylcholine is classified as what type of neuromuscular blocker?

Depolarizing neuromuscular blocker.

What characteristic muscle phenomenon occurs during Phase 1 of succinylcholine action?

Fasciculations (persistent muscle twitching).

During which phase of succinylcholine action does the muscle become insensitive to acetylcholine?

Phase 2, the desensitization phase.

For what urgent clinical procedure is succinylcholine particularly useful?

Rapid sequence intubation (emergency airway management).

List three serious adverse effects associated with succinylcholine.

Hyperkalemia, apnea, and malignant hyperthermia.

Which drug is administered to treat malignant hyperthermia triggered by succinylcholine?

Dantrolene.

Why can organophosphate cholinesterase inhibitors provoke seizures?

They are highly lipid-soluble and penetrate the CNS.

Which plant-derived muscarinic antagonist is the racemic form of hyoscyamine?

Atropine.

What is the therapeutic advantage of cevimeline’s selective M3 agonism in Sjögren’s syndrome?

Stimulates exocrine secretions with fewer cardiac side effects.

How does varenicline differ from nicotine in receptor activity?

Varenicline is a partial agonist at α4β2 receptors, whereas nicotine is a full agonist.

Which cholinesterase inhibitor has an exceptionally short duration of action (~10 minutes)?

Edrophonium.

Why are neostigmine and pyridostigmine less likely to enter the CNS?

They are quaternary ammonium compounds and therefore polar.

What life-threatening condition can excessive atropine dosing cause, necessitating careful antidote use?

Severe anticholinergic toxicity such as tachyarrhythmias and hyperthermia.

Which overactive-bladder agents are M3-selective, reducing cognitive side effects?

Darifenacin and Tolterodine.