A patient with open-angle glaucoma is treated with a muscarinic
stimulant applied directly to the cornea to reduce intraocular
pressure while limiting systemic bradycardia. This benefit is best
explained by:
A. Receptor isoform selectivity
B.
Pharmacokinetic selectivity
C. Intrinsic efficacy
differences
D. Allosteric receptor bias
B. Pharmacokinetic selectivity
A medical student develops diaphoresis, miosis, and bronchospasm
after exposure to a cholinomimetic. The autonomic
neuroeffector–junction effects of acetylcholine and similar drugs are
best termed:
A. Sympatholytic effects
B. Nicotinomimetic
effects
C. Adrenergic effects
D. Parasympathomimetic effects
D. Parasympathomimetic effects
A researcher classifies cholinoceptors by transmembrane signaling
mechanism. Which pairing is correct?
A. Muscarinic—G protein;
Nicotinic—ion channel
B. Muscarinic—ion channel; Nicotinic—G
protein
C. Both are ligand-gated channels
D. Both are G protein–linked
A. Muscarinic—G protein; Nicotinic—ion channel
Which site is most consistent with muscarinic
receptor localization described in autonomic pharmacology?
A.
Synaptic vesicle membrane
B. Mitochondrial inner membrane
C.
Effector-cell plasma membrane
D. Nuclear envelope membrane
C. Effector-cell plasma membrane
What agents bind to and activate muscarinic or nicotinic receptors? Which produce their primary effects by inhibiting acetylcholinesterase?
Direct-acting
Which produce their primary effects by inhibiting acetylcholinesterase?
Indirect-acting
A pesticide exposure causes cholinergic excess by preventing
acetylcholine breakdown. The inhibited enzyme normally hydrolyzes
acetylcholine into:
A. Acetate and ethanol
B. Choline and
acetic acid
C. Choline and propionic acid
D. Acetyl-CoA and choline
B. Choline and acetic acid
A quaternary choline ester shows minimal CNS effects even at high
doses. The most direct physicochemical explanation is that it is
relatively:
A. Nonpolar in plasma
B. Highly
protein-bound
C. Rapidly metabolized hepatically
D.
Insoluble in lipids
D. Insoluble in lipids
Two enantiomers of bethanechol are compared in vitro. One is ~1000×
more potent at muscarinic receptors. Which configuration is more
potent?
A. cis-bethanechol
B. trans-bethanechol
C.
(S)-bethanechol
D. (R)-bethanechol
C. (S)-bethanechol
A clinician wants the longest duration among common choline esters
due to maximal resistance to cholinesterase. Which best fits?
A.
Acetylcholine
B. Bethanechol
C. Choline
D. Methacholine
B. Bethanechol
A toxicology consult notes that certain natural cholinomimetic
alkaloids are well absorbed from most sites because they are tertiary
amines. List them:
A. pilocarpine, nicotine, lobeline
B.
pilocarpine, nicotine, muscarine
C. pilocarpine, nicotine,
bethanechol
D. pilocarpine, methacholine, lobeline
A. pilocarpine, nicotine, lobeline
Several people develop cholinergic toxicity after eating wild
mushrooms. Which agent is specifically noted as a quaternary amine
that can still enter the brain and be toxic when ingested?
A.
Carbachol
B. Methacholine
C. Muscarine
D. Bethanechol
C. Muscarine
A patient ingests a tertiary-amine cholinomimetic. Which intervention
would accelerate clearance based on urinary handling?
A. Urine
alkalinization
B. Forced diuresis only
C. Activated charcoal
only
D. Urine acidification
D. Urine acidification
A patient’s organ response to parasympathetic activation includes
both direct effector changes and reduced neurotransmitter release from
certain nerve terminals. The second mechanism is best described as
acetylcholine acting on muscarinic receptors to:
A. Inhibit
transmitter release
B. Increase transmitter release
C.
Deplete vesicular stores
D. Reverse vesicle fusion
A. Inhibit transmitter release
In a salivary gland acinar cell, a muscarinic agonist produces
increased secretion via a classic second-messenger cascade. Which
pathway is most consistent with M1/M3/M5 activation?
A. cAMP/PKA
rise
B. cGMP/PKG rise
C. IP3/DAG signaling
D. JAK/STAT signaling
C. IP3/DAG signaling
In classic studies of nicotinic receptors, which tool most directly
enabled receptor labeling and isolation because it binds very
tightly?
A. α-bungarotoxin
B. Atropine
C.
Hexamethonium
D. Physostigmine
A. α-bungarotoxin
Why were electric organs especially useful for detailed nicotinic
receptor studies?
A. Minimal receptor density
B. Exclusive
M3 expression
C. No ionic currents present
D. Extremely high
receptor density
D. Extremely high receptor density
A patch-clamp experiment activates neuronal nicotinic receptors.
Which immediate measurable change best supports successful activation
as described?
A. Nuclear transcription rise
B. Ionic
conductance change
C. DNA methylation shift
D. Lysosomal pH change
B. Ionic conductance change
A pharmacologist focuses on neuronal nicotinic
receptors. Their subunit composition is best described as
containing:
A. Only δ and ε subunits
B. α with γ
only
C. α and β only
D. α with δ only
C. α and β only
A drug is desired to produce muscarinic effects with a higher
likelihood of systemic absorption from multiple administration sites
compared with quaternary choline esters. Which agent best fits that
property?
A. Carbachol
B. Bethanechol
C.
Methacholine
D. Nicotine
D. Nicotine
A resident wants a cholinomimetic with poor CNS penetration due to
hydrophilicity and limited distribution. Which choice best
matches?
A. Lobeline
B. Bethanechol
C.
Pilocarpine
D. Nicotine
B. Bethanechol
A patient receives a cholinesterase inhibitor and develops marked
muscarinic effects. The drug class responsible for the
primary pharmacologic effect is best characterized as
inhibiting:
A. Acetylcholinesterase
B. Choline
acetyltransferase
C. Vesicular ACh transporter
D. Nicotinic
receptor opening
A. Acetylcholinesterase
A patient with open-angle glaucoma receives a muscarinic agonist
drop. Which ocular action most directly produces the key pupillary
change?
A. Iris radial contraction
B. Ciliary muscle
relaxation
C. Lens flattening
D. Iris sphincter contraction
D. Iris sphincter contraction
After the same drop, the patient can read fine print better. Which
mechanism explains this near-vision effect?
A. Ciliary muscle
contraction
B. Zonal fiber tightening
C. Lens
flattening
D. Pupillary dilation
A. Ciliary muscle contraction
A healthy volunteer receives a minimally effective IV acetylcholine
infusion (20–50 mcg/min). What pattern is most expected?
A.
Hypertension with bradycardia
B. Hypertension with
tachycardia
C. Hypotension with tachycardia
D. Hypotension
with bradycardia
C. Hypotension with tachycardia
With larger IV acetylcholine doses, which heart-rate response becomes
prominent from direct cardiac effects?
A. Bradycardia
B.
Sinus tachycardia
C. Ventricular tachycardia
D. No rate change
A. Bradycardia
A patient on higher-dose IV acetylcholine develops hypotension. Which
additional finding best fits the same dose range?
A. Increased AV
conduction
B. Increased SA firing
C. Increased
contractility
D. Bradycardia with AV slowing
D. Bradycardia with AV slowing
In isolated atrial tissue, a muscarinic agonist directly reduces the
slow inward calcium current. Which current is decreased?
A.
INa
B. ICa
C. IK1
D. Ito
B. ICa
A pacemaker-cell study shows slower phase 4 depolarization after a
muscarinic agonist. Which current is reduced?
A. IKs
B.
IKr
C. If
D. ICa
C. If
A patient has only mild net bradycardia after a muscarinic agonist
despite strong direct SA slowing. Best explanation?
A. Reflex
sympathetic discharge
B. SA receptor downregulation
C.
Increased vagal tone
D. Direct β1 stimulation
A. Reflex sympathetic discharge
In an artery-ring lab, endothelium is mechanically removed. Which
acetylcholine vascular response is most affected?
A. Increased
venous tone
B. Increased arterial stiffness
C. Enhanced
smooth muscle growth
D. Endothelium-dependent vasodilation
D. Endothelium-dependent vasodilation
The receptor subtype responsible for acetylcholine-induced
vasodilation on intact endothelium is:
A. M1
B. M3
C.
M2
D. M5
B. M3
A vasodilatory response to muscarinic stimulation depends on release
of endothelium-derived relaxing factor. The mediator is:
A.
Endothelin-1
B. Thromboxane A2
C. Nitric oxide
D. Histamine
C. Nitric oxide
A patient with asthma receives a systemic muscarinic agonist. Which
airway effect is most likely?
A. Bronchial smooth muscle
contraction
B. Bronchial smooth muscle relaxation
C. Reduced
mucus secretion
D. Increased ciliary beat frequency
A. Bronchial smooth muscle contraction
After cholinomimetic exposure, a patient develops cramping and
diarrhea. Which GI change best explains this?
A. Decreased
motility and secretion
B. Decreased motility only
C.
Increased secretion only
D. Increased motility and secretion
D. Increased motility and secretion
A muscarinic agonist is given for urinary retention. Which
coordinated bladder effect promotes voiding?
A. Detrusor relaxes;
sphincter contracts
B. Detrusor contracts; sphincter
relaxes
C. Trigone contracts; detrusor relaxes
D. Sphincter
contracts; trigone contracts
B. Detrusor contracts; sphincter relaxes
A patient on a muscarinic agonist reports watery eyes, runny nose,
and heavy sweating. Which glands are directly stimulated?
A.
Sebaceous glands, lacrimal, nasal
B. Apocrine sweat glands,
lacrimal, nasal
C. Thermoregulatory sweat, lacrimal,
nasal
D. Thyroid and parotid glands, lacrimal, nasal
C. Thermoregulatory sweat, lacrimal, nasal
A cognition study targets the muscarinic subtype richly expressed in
brain regions involved in cognition. Which subtype is it?
A.
M2
B. M3
C. M4
D. M1
D. M1
Despite fewer nicotinic than muscarinic receptors, nicotine and
lobeline strongly affect which CNS regions?
A. Brain stem and
cortex
B. Cerebellum and thalamus
C. Basal ganglia and
pons
D. Spinal cord and midbrain
A. Brain stem and cortex
In hippocampal circuits, acetylcholine regulates norepinephrine
release via which nicotinic receptor subtype?
A. α4β2
B.
α7
C. α3β4
D. α1β1γδ
C. α3β4
A presynaptic mechanism in hippocampus and cortex limits further
cholinergic signaling. What effect is described?
A. Increased
acetylcholine release
B. Inhibited acetylcholine release
C.
Increased norepinephrine reuptake
D. Decreased dopamine synthesis
B. Inhibited acetylcholine release
The most abundant nicotinic receptor oligomer in the brain
is:
A. α3β4
B. α3
C. α7
D. α4β2
D. α4β2
Chronic nicotine exposure produces which sequence at nicotinic
receptors?
A. Depolarization then desensitization
B.
Desensitization then depolarization
C. Blockade then
sensitization
D. Internalization then activation
A. Depolarization then desensitization
A patient ingests high-concentration nicotine and develops tremor and
emesis. What additional central effect best fits?
A. Respiratory
center suppression
B. Phrenic nerve blockade
C. Respiratory
center stimulation
D. Central chemoreceptor inhibition
C. Respiratory center stimulation
A drug-development team targets a nicotinic subtype linked to
cognition and pain perception. Which subtype matches?
A.
α3
B. α7
C. α4β2
D. α3β4
B. α7
Proposed anti-inflammatory actions of α7 nicotinic receptors are
based on their presence on:
A. Hepatocytes
B. Skeletal
myocytes
C. Erythrocytes
D. Immune nonneuronal cells
D. Immune nonneuronal cells
Fast excitatory transmission in autonomic ganglia is primarily
mediated by which nicotinic subtype?
A. α3
B. α4β2
C.
α7
D. α3β4
A. α3
In autonomic ganglia and adrenal medulla, heteromeric neuronal nAChRs
commonly include α3 plus:
A. β1 and β3 subunits
B. β2
only
C. β2 and β4 subunits
D. δ and ε subunits
C. β2 and β4 subunits
Compared with skeletal muscle nAChRs, nicotine has somewhat greater
affinity for:
A. Neuronal nicotinic receptors
B. Muscarinic
M3 receptors
C. Skeletal nicotinic receptors
D. GABA-A receptors
A. Neuronal nicotinic receptors
Which best fits deficiency? Microcystis (inadequate development of
the urinary bladder), microcolon, and intestinal hypoperistalsis
syndrome; urinary incontinence, urinary bladder distention, and
mydriasis.
A. a3
B. b2
C. b4
D. m3
D. m3
A depolarizing nicotinic agonist that is not rapidly hydrolyzed
causes weakness after initial activation. The transmission block most
directly reflects:
A. Depolarization blockade
B. Competitive
antagonism
C. Vesicular ACh depletion
D. Presynaptic Ca2+ blockade
A. Depolarization blockade
Nicotinic agonist applied to an end plate by iontophoresis causes
immediate depolarization. The primary ionic basis is increased
permeability to:
A. Ca2+ and Cl−
B. Na+ and K+
C. K+
and Cl−
D. Na+ and Ca2+
B. Na+ and K+
A very brief-acting cholinesterase inhibitor is used diagnostically
because it is a simple alcohol with a quaternary ammonium. Which drug
fits?
A. Neostigmine
B. Physostigmine
C.
Echothiophate
D. Edrophonium
D. Edrophonium
Which agent is a carbamic acid ester cholinesterase inhibitor
(carbamate) used clinically?
A. Neostigmine
B.
Echothiophate
C. Edrophonium
D. Sarin
A. Neostigmine
Which drug is an organophosphate cholinesterase inhibitor used
clinically?
A. Physostigmine
B. Neostigmine
C.
Echothiophate
D. Edrophonium
C. Echothiophate
An insecticide is engineered for very high lipid solubility to speed
absorption into insects and rapid CNS distribution. Which is
typical?
A. Echothiophate
B. Carbaryl
C.
Edrophonium
D. Physostigmine
B. Carbaryl
A clinician prefers an organophosphate with very long duration but
improved stability in aqueous solution. Which agent best
matches?
A. Sarin
B. Echothiophate
C. Carbaryl
D. Neostigmine
B. Echothiophate
A military exposure causes profound cholinergic crisis; the agent is
an extremely potent “nerve gas.” Which is most consistent?
A.
Sarin
B. Edrophonium
C. Physostigmine
D. Neostigmine
A. Sarin
A quaternary carbamate requires a much larger oral dose than
parenteral dosing. The best explanation is:
A. Rapid renal
secretion only
B. Extensive first-pass oxidation
C.
Permanent charge limits lipids
D. High plasma protein binding
C. Permanent charge limits lipids
An AChE inhibitor is well absorbed from all sites and can be used
topically in the eye. Which drug fits?
A. Neostigmine
B.
Edrophonium
C. Echothiophate
D. Physostigmine
D. Physostigmine
Most organophosphate cholinesterase inhibitors are dangerous to
humans because they are:
A. Poorly absorbed from skin
B.
Well absorbed from mucosa
C. Selective for plasma enzymes
D.
Rapidly hydrolyzed in blood
B. Well absorbed from mucosa
Which organophosphate is noted as highly polar and more stable than
most others?
A. Echothiophate
B. Sarin
C.
Malathion
D. Carbaryl
A. Echothiophate
You want an AChE inhibitor lasting about 5–15 minutes. Which duration
matches best?
A. Physostigmine
B. Pyridostigmine
C.
Edrophonium
D. Echothiophate
C. Edrophonium
A postoperative patient needs an AChE inhibitor with 0.5–4 hour
action. Which agent best matches?
A. Pyridostigmine
B.
Neostigmine
C. Echothiophate
D. Edrophonium
B. Neostigmine
A patient needs sustained symptomatic coverage with an AChE inhibitor
lasting 4–6 hours. Which duration fits?
A. Neostigmine
B.
Physostigmine
C. Echothiophate
D. Pyridostigmine
D. Pyridostigmine
A clinician selects an AChE inhibitor with 0.5–2 hour duration and
good absorption from all sites. Which best fits?
A.
Physostigmine
B. Edrophonium
C. Neostigmine
D. Pyridostigmine
A. Physostigmine
A glaucoma regimen uses an AChE inhibitor with ~100-hour duration.
Which drug matches?
A. Neostigmine
B. Echothiophate
C.
Physostigmine
D. Edrophonium
B. Echothiophate
Beyond acetylcholinesterase, these inhibitors also inhibit which
enzyme?
A. Monoamine oxidase
B.
Butyrylcholinesterase
C. Dopamine β-hydroxylase
D. Catechol-O-methyltransferase
B. Butyrylcholinesterase
A child with α3-subunit deficiency is evaluated. Which combination
best matches the syndrome?
A. Microcolon and
hyperperistalsis
B. Microcystis and microcolon
C. Megacystis
and megacolon
D. Microcystis and tachycardia
B. Microcystis and microcolon
A pathologist samples adrenal medulla ganglion-like tissue. Which
nAChR subunit pattern is most expected there?
A. α1β1γδ
only
B. α7 only
C. α3 with β2/β4
D. α4β2 only
C. α3 with β2/β4
Quaternary agents reversibly bind _____ and by _____ bonds
to the active site, thus preventing access of acetylcholine.
A.
electrostatically, hydrogen
B. covalently, hydrogen
C.
noncovalently, carbon
D. covalently, carbon
A. electrostatically, hydrogen
A new AChE inhibitor forms a covalent carbamoylated enzyme that is
slowly hydrolyzed, prolonging recovery for 30 minutes to 6
hours. This mechanism best fits:
A. Quaternary alcohol
inhibitors
B. Direct muscarinic agonists
C. Organophosphate
nerve agents
D. Carbamate ester inhibitors
D. Carbamate ester inhibitors
Which pair are classic examples of carbamate ester AChE
inhibitors?
A. Edrophonium and atropine
B. Neostigmine and
physostigmine
C. Echothiophate and sarin
D. Pilocarpine and cevimeline
B. Neostigmine and physostigmine
The most prominent pharmacologic effects of cholinesterase inhibitors
are most evident in:
A. CV, GI, eye, NMJ
B. Liver, kidney,
spleen, bone
C. Thyroid, pancreas, testes, skin
D. Lung,
pleura, marrow, lymph
A. CV, GI, eye, NMJ
A lipid-soluble AChE inhibitor at low concentration produces diffuse
EEG activation and subjective alertness. This effect most directly
reflects:
A. Neuromuscular transmission failure
B. Primary
vascular smooth muscle action
C. Peripheral muscarinic
blockade
D. Central cholinergic stimulation
D. Central cholinergic stimulation
At high concentrations, lipid-soluble AChE inhibitors can cause
generalized convulsions followed by coma and:
A. Severe
hyperthermia
B. Respiratory arrest
C. Acute hepatic
necrosis
D. Ventricular fibrillation
B. Respiratory arrest
A patient exposed to an AChE inhibitor shows increased autonomic
outflow. These drugs can increase activity in:
A. Only
parasympathetic ganglia
B. Only sympathetic ganglia
C. Both
sympathetic and parasympathetic
D. Only postganglionic terminals
C. Both sympathetic and parasympathetic
Edrophonium, neostigmine, and physostigmine most closely mimic which
physiologic input on the heart?
A. Renin-angiotensin
activation
B. Carotid body stimulation
C. Cardiac β1
stimulation
D. Vagal nerve activation
D. Vagal nerve activation
Cholinesterase inhibitors have minimal effects by direct
action on vascular smooth muscle because:
A. Most beds lack
cholinergic innervation
B. Vascular AChE is absent
C.
Vascular muscle lacks muscarinic receptors
D. Blood vessels lack
smooth muscle
A. Most beds lack cholinergic innervation
Moderate doses of AChE inhibitors can raise blood pressure primarily
by increasing systemic:
A. Venous capacitance
B. Stroke
volume
C. Vascular resistance
D. Plasma volume
C. Vascular resistance
In quaternary nitrogen AChE inhibitors, the pressor response is
initiated mainly at:
A. Carotid baroreceptors
B. Sympathetic
ganglia
C. Ventricular myocardium
D. Renal juxtaglomerular cells
B. Sympathetic ganglia
In lipid-soluble AChE inhibitors, the pressor response can also be
initiated at:
A. Central sympathetic centers
B. Ventral horn
motor neurons
C. Endothelial M3 receptors
D. AV nodal pacemakers
A. Central sympathetic centers
A patient given an AChE inhibitor develops increased BP and plasma
norepinephrine; atropine prevents both. This best implies atropine
acts:
A. At NMJ
B. At endothelium
C. At parasympathetic
ganglia
D. In central and peripheral sites
D. In central and peripheral sites
Net cardiovascular effects of moderate-dose AChE inhibitors most
often include:
A. Tachycardia with hypotension
B.
Bradycardia with hypertension
C. Tachycardia with
hypertension
D. Bradycardia with hypotension
B. Bradycardia with hypertension
Low therapeutic AChE inhibitor doses primarily:
A. Block
physiologic ACh release
B. Decrease synaptic ACh
concentration
C. Prolong released ACh effects
D. Desensitize
nicotinic receptors
C. Prolong released ACh effects
A patient has weakness after a curare-like blocker. An AChE inhibitor
improves strength mainly by increasing:
A. Contraction strength
at NMJ
B. Myosin ATPase activity
C. Calcium release from
SR
D. Sodium channel inactivation
A. Contraction strength at NMJ
A key clinical use category of cholinomimetics is treatment
of:
A. Essential hypertension
B. Hyperthyroidism
C.
Bacterial meningitis
D. Alzheimer’s disease
D. Alzheimer’s disease
Muscarinic stimulants and AChE inhibitors reduce intraocular pressure
chiefly by:
A. Iris radial contraction
B. Decreased
episcleral venous pressure
C. Ciliary body contraction
D.
Increased aqueous production
C. Ciliary body contraction
In depressed smooth muscle activity without obstruction,
cholinomimetics may be helpful. Before use, the clinician must
exclude:
A. Hypovolemia
B. Mechanical obstruction
C.
Fever
D. Hypercalcemia
B. Mechanical obstruction
Among choline ester cholinomimetics, the most widely used for GI/GU
disorders is:
A. Acetylcholine
B. Bethanechol
C.
Carbachol
D. Methacholine
B. Bethanechol
A patient with chronic xerostomia is treated with a long-used agent
to increase salivary secretion. Which fits?
A.
Pilocarpine
B. Echothiophate
C. Pyridostigmine
D. Atropine
A. Pilocarpine
A patient with Sjögren syndrome and dry mouth is started on a newer
direct-acting muscarinic agonist. Which drug is intended?
A.
Physostigmine
B. Cevimeline
C. Neostigmine
D. Edrophonium
B. Cevimeline
In myasthenia gravis, antibodies target the main immunogenic region on which nicotinic receptor subunit?
α1
One MG mechanism reduces receptor number, accelerating
internalization and degradation. This is best described as:
A.
Complement inhibition
B. Presynaptic blockade
C. Receptor
cross-linking
D. Vesicular depletion
C. Receptor cross-linking
Another MG mechanism reduces transmission when antibodies bind the
receptor and:
A. Inhibit receptor function
B. Increase ACh
release
C. Enhance channel opening
D. Activate G proteins
A. Inhibit receptor function
A patient with generalized MG remains weak despite optimized
pyridostigmine. Which adjunct is most appropriate for more widespread
weakness?
A. Immunosuppressant therapy
B. Chronic β-agonist
therapy
C. High-dose atropine daily
D. Long-term organophosphate
A. Immunosuppressant therapy
A bedside edrophonium test is planned for suspected MG. After
baseline strength is measured, what is the initial IV dose?
A. 1
mg
B. 2 mg
C. 5 mg
D. 10 mg
B. 2 mg
No effect is seen 45 seconds after the initial edrophonium dose. What
additional dose may be administered?
A. 3 mg
B. 5 mg
C.
8 mg
D. 12 mg
C. 8 mg
Following edrophonium in true MG, improvement in strength typically
lasts about:
A. 30 seconds
B. 30 minutes
C. 2
hours
D. 5 minutes
D. 5 minutes
Long-term symptomatic therapy for MG is most commonly maintained
with:
A. Tacrine
B. Donepezil
C. Pyridostigmine
D. Echothiophate
C. Pyridostigmine
If pyridostigmine cannot be used for MG maintenance, the classic
alternative is:
A. Neostigmine
B. Physostigmine
C.
Edrophonium
D. Galantamine
A. Neostigmine
Because AChE inhibitors are short-acting, pyridostigmine often
requires dosing about every:
A. 2 hours
B. 4 hours
C. 6
hours
D. 12 hours
C. 6 hours
Neostigmine often requires dosing about every:
A. 4
hours
B. 6 hours
C. 8 hours
D. 24 hours
A. 4 hours
After surgery, rapid reversal of nondepolarizing neuromuscular
blockade is commonly accomplished with:
A. Neostigmine or
edrophonium
B. Tacrine or donepezil
C. Pilocarpine or
cevimeline
D. Atropine or scopolamine
A. Neostigmine or edrophonium
Which toxidrome is potentially lethal in children and can cause
prolonged behavioral disturbance and arrhythmias in adults?
A.
Nicotine intoxication
B. Atropine intoxication
C.
Cholinergic crisis
D. Opioid intoxication
B. Atropine intoxication
A suicidal ingestion causes severe muscarinic blockade and QRS
widening risk. Which drug class is classically implicated?
A.
SSRIs
B. Tricyclic antidepressants
C. MAO inhibitors
D. Antipsychotics
B. Tricyclic antidepressants
The first drug used for mild-to-moderate Alzheimer’s disease with
anticholinesterase and other cholinomimetic actions was:
A.
Tacrine
B. Rivastigmine
C. Galantamine
D. Donepezil
A. Tacrine
Which set are newer, more selective AChE inhibitors with similar
marginal benefit but less toxicity than tacrine?
A. Donepezil,
galantamine, rivastigmine
B. Neostigmine, edrophonium,
physostigmine
C. Pilocarpine, cevimeline, bethanechol
D.
Atropine, scopolamine, ipratropium
A. Donepezil, galantamine, rivastigmine
Overdose of pilocarpine or choline esters most predictably
causes:
A. Muscarinic excess signs
B. Pure nicotinic
blockade
C. Isolated CNS depression
D. α-adrenergic activation
A. Muscarinic excess signs
Which symptom set best matches muscarinic excess from cholinomimetic
overdose?
A. Urinary urgency and sweating
B. Mydriasis and
dry skin
C. Constipation and tachycardia
D. Hyperthermia and delirium
A. Urinary urgency and sweating
The most dangerous toxic effect of large nicotine doses includes
central stimulation causing:
A. Hyporeflexia
B.
Convulsions
C. Catatonia
D. Miosis
B. Convulsions
Another dangerous nicotine toxicity mechanism is end-plate:
A.
Hyperpolarization
B. Depolarization
C. Demyelination
D.
Calcium depletion
B. Depolarization
Severe nicotine toxicity can also produce hypertension with
cardiac:
A. Asystole only
B. Arrhythmias
C.
Tamponade
D. Pericarditis
B. Arrhythmias
The primary neurotransmitter of the parasympathetic nervous system
is:
A. Dopamine
B. Norepinephrine
C.
Acetylcholine
D. Serotonin
C. Acetylcholine
Muscarinic receptors are GPCRs with how many transmembrane domains?
7
The muscarinic receptor domain classically coupled to G proteins is
the:
A. 1st extracellular loop
B. 2nd extracellular
loop
C. 2nd cytoplasmic loop
D. 3rd cytoplasmic loop
D. 3rd cytoplasmic loop
Nicotinic receptors are primarily found in which set of
locations?
A. Autonomic ganglia, skeletal NMJ, adrenal
B.
Thyroid, liver, kidney
C. Retina, cochlea, lens
D. Spleen,
pancreas, marrow
A. Autonomic ganglia, skeletal NMJ, adrenal
What agents bind to and activate muscarinic or nicotinic receptors?
Direct-acting
M2 receptor—best matching location, G protein, and pathway:
A.
Heart nodes; Gi; ↓cAMP
B. CNS; Gq; IP3/DAG
C. Smooth muscle;
Gq; IP3/DAG
D. Glands; Gi; ↓cAMP
A. Heart nodes; Gi; ↓cAMP
M3 receptor—best matching location, G protein, and pathway:
A.
Heart; Gi; ↓cAMP
B. CNS; Gi; ↓cAMP
C. Smooth muscle/glands;
Gq; IP3/DAG
D. Skeletal NMJ; ion channel
C. Smooth muscle/glands; Gq; IP3/DAG
M4 and M5 are CNS receptors. Which pairing is correct?
A. M4:
Gq/IP3; M5: Gi/↓cAMP
B. M4: Gi/↓cAMP; M5: Gq/IP3
C. M4:
Gs/↑cAMP; M5: Gi/↓cAMP
D. M4: ion channel; M5: Gq/IP3
B. M4: Gi/↓cAMP; M5: Gq/IP3
In a healthy artery with intact endothelium, acetylcholine activates
M3 receptors. Net vascular effect is:
A. Vasoconstriction via
Ca2+ influx
B. No change in vascular tone
C. Vasodilation
via NO release
D. Vasoconstriction via endothelin
C. Vasodilation via NO release
The key smooth-muscle second messenger that mediates NO-driven
relaxation is:
A. cGMP
B. IP3
C. cAMP
D. DAG
A. cGMP
In an endothelium-denuded vessel ring, acetylcholine most likely
causes:
A. Vasodilation via prostacyclin
B. Vasodilation via
NO
C. No response without endothelium
D. Vasoconstriction
via IP3-Ca2+
D. Vasoconstriction via IP3-Ca2+
A direct-acting cholinomimetic produces effects primarily by:
A.
Blocking vesicular ACh uptake
B. Activating M or N
receptors
C. Inhibiting COMT
D. Stimulating NE release
B. Activating M or N receptors
Butyrylcholinesterase inhibition matters clinically because it can
act as a:
A. Cardiac pacemaker stabilizer
B. Muscarinic
receptor chaperone
C. Nicotinic channel pore blocker
D.
Biological scavenger enzyme
D. Biological scavenger enzyme
Which list contains only choline ester direct
agonists?
A. Nicotine, muscarine, lobeline, pilocarpine
B.
ACh, methacholine, carbachol, bethanechol
C. Neostigmine,
pyridostigmine, edrophonium, physostigmine
D. Atropine,
scopolamine, ipratropium, tiotropium
B. ACh, methacholine, carbachol, bethanechol
Choline ester lipid insolubility is mainly due to:
A. Multiple
aromatic rings
B. High molecular weight
C. Sulfhydryl side
chains
D. Quaternary ammonium charge
D. Quaternary ammonium charge
Which list contains only alkaloid direct agonists?
A.
ACh, methacholine, carbachol, bethanechol
B. Neostigmine,
physostigmine, echothiophate, edrophonium
C. Muscarine,
pilocarpine, nicotine, lobeline
D. Atropine, scopolamine,
tiotropium, ipratropium
C. Muscarine, pilocarpine, nicotine, lobeline
Which agent reliably activates both muscarinic and
nicotinic receptors?
A. Carbachol
B. Bethanechol
C.
Pilocarpine
D. Muscarine
A. Carbachol
Neonicotinoid insecticides act primarily at:
A. Muscarinic
receptors
B. GABA-A receptors
C. Nicotinic receptors
D.
Dopamine receptors
C. Nicotinic receptors
In the PLC pathway, DAG primarily:
A. Releases Ca2+ from
SR
B. Inhibits adenylate cyclase
C. Activates guanylyl
cyclase
D. Activates protein kinase C
D. Activates protein kinase C
In the PLC pathway, IP3 primarily:
A. Opens Na+ channels
B.
Releases Ca2+ from stores
C. Inhibits phosphodiesterase
D.
Activates PKC directly
B. Releases Ca2+ from stores
M2 and M4 receptor signaling most directly:
A. Activates
PLC
B. Activates tyrosine kinase
C. Inhibits adenylate
cyclase
D. Opens NMJ Na+ channels
C. Inhibits adenylate cyclase
In cardiac tissue, muscarinic stimulation most
characteristically:
A. Increases K+ flux
B. Decreases K+
flux
C. Increases Na+ flux
D. Decreases Cl− flux
A. Increases K+ flux
In autonomic ganglia and many smooth muscles, muscarinic stimulation
tends to:
A. Increase K+ efflux
B. Increase K+
influx
C. Increase Ca2+ influx
D. Decrease K+ flux
D. Decrease K+ flux
With nicotinic receptors, binding both agonist
sites:
A. Closes the channel rapidly
B. Prevents ion
selectivity
C. Lowers opening probability
D. Greatly
increases opening probability
D. Greatly increases opening probability
Binding only one nicotinic site typically:
A.
Abolishes channel opening
B. Forces full channel opening
C.
Increases opening probability
D. Converts receptor to GPCR
C. Increases opening probability
A glaucoma drop causes miosis and accommodation. These
changes:
A. Reduce Schlemm canal flow
B. Increase aqueous
outflow
C. Increase aqueous production
D. Block trabecular drainage
B. Increase aqueous outflow
The aqueous humor drainage structure most directly facilitated is
the:
A. Canal of Schlemm
B. Ciliary processes
C.
Vitreous chamber
D. Choroid plexus
A. Canal of Schlemm
A muscarinic agonist slows the SA node primarily
by:
A. Increasing conduction velocity
B. Decreasing firing
rate
C. Increasing contractile force
D. Shortening refractoriness
B. Decreasing firing rate
At the AV node, muscarinic activation most
characteristically:
A. Increases conduction velocity
B.
Shortens refractory period
C. Slows conduction; ↑
refractory
D. Triggers ventricular ectopy
C. Slows conduction; ↑ refractory
In the atria, muscarinic stimulation most
characteristically:
A. Decreases strength; ↓ refractory
B.
Increases force; ↓ refractory
C. Decreases force; ↑
refractory
D. Increases force; ↑ refractory
A. Decreases strength; ↓ refractory
In the ventricles, muscarinic stimulation produces
a:
A. Large force increase
B. Small strength
decrease
C. Large force decrease
D. No change in force
B. Small strength decrease
Direct cardiac muscarinic effects include increasing
which current?
A. If current
B. Slow inward Ca
current
C. Fast Na current
D. K current
D. K current
Direct cardiac muscarinic effects include decreasing
which current?
A. Delayed rectifier K current
B. Funny If
current
C. Slow inward Ca current
D. Fast Na current
C. Slow inward Ca current
Muscarinic slowing of diastolic depolarization includes
reducing:
A. Hyperpolarization-activated current
B. Rapid Na
current
C. Transient outward K current
D. L-type Ca current
A. Hyperpolarization-activated current
Without intact endothelium, ACh can constrict vessels because M3 on
VSM triggers:
A. cGMP fall with relaxation
B. IP3-mediated
Ca2+ rise
C. cAMP rise with relaxation
D. β2-mediated hyperpolarization
B. IP3-mediated Ca2+ rise
A systemic muscarinic agonist most predictably causes:
A.
Bronchoconstriction
B. Bronchodilation
C. Reduced airway
mucus
D. Increased dead-space ventilation
A. Bronchoconstriction
Typical GI effects of muscarinic stimulation include:
A. ↓
peristalsis; ↑ sphincters
B. ↑ peristalsis; ↑ sphincters
C.
↑ peristalsis; ↓ sphincters
D. ↓ secretion; ↑ sphincters
C. ↑ peristalsis; ↓ sphincters
A notable exception to “sphincters relax” is the:
A. Internal
urethral sphincter
B. Pyloric sphincter
C. Internal anal
sphincter
D. Gastroesophageal sphincter
D. Gastroesophageal sphincter
Relative abundance is best summarized as:
A. Brain muscarinic;
spinal nicotinic
B. Brain nicotinic; spinal muscarinic
C.
Brain muscarinic; spinal muscarinic
D. Brain nicotinic; spinal nicotinic
A. Brain muscarinic; spinal nicotinic
M1 receptors are cognition-linked; M1 knockout is associated
with:
A. Increased appetite and obesity
B. Severe
neuromuscular paralysis
C. Impaired forebrain plasticity
D.
Loss of spinal pain reflexes
C. Impaired forebrain plasticity
Hypothalamic M3 receptor knockout is associated with:
A.
Increased body fat mass
B. Increased appetite signals
C.
Hyperphagia with obesity
D. Reduced appetite and fat
D. Reduced appetite and fat
Regarding autonomic ganglia, nicotine’s action on sympathetic vs
parasympathetic is:
A. Same direction in both
B. Opposite
direction in both
C. Only parasympathetic affected
D. Only
sympathetic affected
A. Same direction in both
Nicotine’s cardiovascular effects are best described
as:
A. Parasympathomimetic
B. Sympathomimetic
C. Purely
muscarinic
D. Purely ganglionic block
B. Sympathomimetic
Nicotine’s GI and urinary effects are best described
as:
A. Sympathomimetic
B. Antimuscarinic
C.
Parasympathomimetic
D. Purely nicotinic blockade
C. Parasympathomimetic
Which agent is muscarinic-selective and a choline ester?
A.
Carbachol
B. Nicotine
C. Lobeline
D. Bethanechol
D. Bethanechol
A pharmacology exam asks for two carbamate
indirect-acting cholinomimetics. Which pair is correct?
A.
Edrophonium, pyridostigmine
B. Neostigmine, physostigmine
C.
Echothiophate, sarin
D. Pilocarpine, bethanechol
B. Neostigmine, physostigmine
A farmer presents after insecticide exposure; you suspect an
organophosphate. Which set contains only
organophosphate examples from your notes?
A.
Echothiophate, sarin, malathion
B. Neostigmine, sarin,
bethanechol
C. Edrophonium, physostigmine, sarin
D.
Pilocarpine, parathion, neostigmine
A. Echothiophate, sarin, malathion
Parathion and malathion are best characterized as:
A. Active
phosphates in humans
B. Quaternary carbamate salts
C.
Thiophosphate prodrugs
D. Direct muscarinic agonists
C. Thiophosphate prodrugs
You need a very short-acting alcohol AChE inhibitor
for bedside testing. Best choice?
A. Edrophonium
B.
Neostigmine
C. Physostigmine
D. Echothiophate
A. Edrophonium
Most organophosphates are highly lipid-soluble liquids. Which
exception is more aqueous-stable yet still
long-acting?
A. Sarin
B. Malathion
C.
Echothiophate
D. Parathion
C. Echothiophate
Which class is generally better absorbed and
therefore more dangerous to humans (and effective
insecticides)?
A. Quaternary alcohols
B. Carbamates
C.
Choline esters
D. Organophosphates
D. Organophosphates
Which group typically has poor absorption because of
permanent charge, requiring larger oral doses?
A. Lipid-soluble
organophosphates
B. Quaternary carbamates
C. Thiophosphate
nerve gases
D. Tertiary AChE inhibitors
B. Quaternary carbamates
Carbamate and organophosphate AChE inhibitors share a key step: after
binding AChE, the ____ portion leaves rapidly.
A. Phosphate
portion
B. Carbamate ion
C. Alcohol portion
D. Acetyl portion
C. Alcohol portion
In that same shared mechanism, the ____ remains bound and is released
slowly.
A. Acidic portion
B. Alcohol portion
C. Choline
portion
D. Water molecule
A. Acidic portion
The functional result of carbamate/organophosphate AChE inhibition is
best summarized as:
A. Increased choline uptake
B. Increased
ACh synthesis
C. Direct receptor antagonism
D. Blocked ACh hydrolysis
D. Blocked ACh hydrolysis
Rank duration (longest → shortest): edrophonium, carbamates,
organophosphates.
A. Carbamates > edrophonium >
organophosphates
B. Organophosphates > carbamates >
edrophonium
C. Edrophonium > organophosphates >
carbamates
D. Organophosphates > edrophonium > carbamates
B. Organophosphates > carbamates > edrophonium
A student asks what is most prescribed now for
chronic glaucoma (instead of cholinomimetics). Best answer?
A.
Pilocarpine plus neostigmine
B. Atropine plus timolol
C. PG
analogs and topical β-blockers
D. Methacholine and acetazolamide
C. PG analogs and topical β-blockers
Acute angle-closure glaucoma is a medical emergency. Initial medical
therapy commonly includes:
A. Pilocarpine
B.
Donepezil
C. Atropine
D. Varenicline
A. Pilocarpine
After IOP control in angle-closure glaucoma, definitive correction is
typically:
A. Trabeculectomy
B. Cataract extraction
C.
Vitrectomy
D. Laser iridotomy
D. Laser iridotomy
A 5-year-old with hyperopia develops strabismus triggered by focusing
effort. This fits:
A. Convergence spasm
B. Accommodative
esotropia
C. CN VI palsy
D. Internuclear ophthalmoplegia
B. Accommodative esotropia
Non-obstructive GI dysmotility (eg, post-op ileus): which drug is
usually used?
A. Neostigmine
B. Echothiophate
C.
Pilocarpine
D. Bethanechol
D. Bethanechol
Bethanechol’s clinical profile is best described as:
A.
Increases GI/GU motility, secretions
B. Selective nicotinic
ganglionic blocker
C. CNS-only acetylcholinesterase
inhibitor
D. Long-acting organophosphate insecticide
A. Increases GI/GU motility, secretions
Another MG mechanism reduces transmission via:
A. Terminal
sprouting failure
B. Reduced ACh synthesis
C. Postsynaptic
membrane lysis
D. Increased ACh breakdown
C. Postsynaptic membrane lysis
MG antibodies can also bind the receptor and:
A. Increase
channel open time
B. Inhibit receptor function
C. Enhance
ACh release
D. Activate G proteins
B. Inhibit receptor function
A patient has ptosis and fatigable proximal weakness. Which bedside
diagnostic drug is used IV?
A. Pyridostigmine
B.
Bethanechol
C. Donepezil
D. Edrophonium
D. Edrophonium
MG patients are notably sensitive to which agents during
anesthesia?
A. Curariform blockers
B. β-agonists
C.
Nitrates
D. Acetazolamide
A. Curariform blockers
A nondepolarizing neuromuscular relaxant listed as an anesthesia
adjunct is:
A. Pancuronium
B. Succinylcholine
C.
Lidocaine
D. Diazepam
A. Pancuronium
Immediate reversal of pharmacologic nondepolarizing paralysis post-op
commonly uses:
A. Donepezil and rivastigmine
B. Pilocarpine
and bethanechol
C. Neostigmine and edrophonium
D. Malathion
and parathion
C. Neostigmine and edrophonium
Which finding is least consistent with classic AChE
inhibitor toxicity (DUMBBELS)?
A. Bronchospasm
B.
Lacrimation
C. Bradycardia
D. Mydriasis
D. Mydriasis
Flaccid paralysis in severe AChE inhibitor poisoning is most directly
due to:
A. NMJ AChR overactivation
B. Direct myosin
inhibition
C. Na+ channel blockade
D. NMJ receptor destruction
A. NMJ AChR overactivation
A patient eats Inocybe mushrooms and develops salivation, diarrhea,
bronchospasm. Best antidote?
A. Pralidoxime
B.
Physostigmine
C. Atropine
D. Neostigmine
C. Atropine
Nicotine replacement with varenicline works because it is a partial
agonist at:
A. α7 nAChR
B. α4β2 nAChR
C. M2
receptor
D. GABA-A receptor
B. α4β2 nAChR
Varenicline reduces nicotine reinforcement mainly by reducing
presynaptic:
A. GABA release
B. Serotonin release
C. NE
reuptake
D. Dopamine release
D. Dopamine release
The major cause of acute cholinergic toxicity worldwide is exposure
to:
A. Organophosphate insecticides
B. Tricyclic
antidepressants
C. Belladonna alkaloids
D. Antihistamines
A. Organophosphate insecticides
In organophosphate poisoning, which drug restores AChE activity at
muscarinic/nicotinic sites but not CNS?
A. Donepezil
B.
Atropine
C. Pralidoxime
D. Pilocarpine
C. Pralidoxime
In organophosphate poisoning, which drug reverses central and
peripheral muscarinic toxicity but not flaccid
paralysis?
A. Pralidoxime
B. Atropine
C.
Pyridostigmine
D. Rivastigmine
B. Atropine
Chronic cholinesterase inhibitor exposure can cause delayed
neuropathy via NTE inhibition. Prototype agent?
A.
Malathion
B. Echothiophate
C. Sarin
D. Triorthocresyl phosphate
D. Triorthocresyl phosphate
Which cholinomimetic is used for asthma challenge testing due to
bronchoconstriction?
A. Bethanechol
B. Methacholine
C.
Pilocarpine
D. Varenicline
B. Methacholine
Varenicline use may be limited by which adverse-effect
cluster?
A. Nephrolithiasis, rash, anemia
B. Hypotension,
bradycardia, syncope
C. Hepatitis, pancreatitis,
arrhythmia
D. Nausea, insomnia, psychiatric worsening
D. Nausea, insomnia, psychiatric worsening
Typical severe organophosphate poisoning progression is best
described as:
A. Nicotinic → CNS → muscarinic
B. Muscarinic
→ CNS → nicotinic
C. CNS → muscarinic → nicotinic
D. CNS →
nicotinic → muscarinic
B. Muscarinic → CNS → nicotinic
Pralidoxime’s limitation in organophosphate poisoning is that
it:
A. Cannot enter CNS
B. Worsens bronchospasm
C.
Blocks nicotinic receptors
D. Causes irreversible AChE inhibition
A. Cannot enter CNS
Parathion and malathion insecticides are “inactive” because they
require conversion to:
A. Carbamate derivatives
B.
Quaternary alcohols
C. Phosphate derivatives
D. Muscarinic antagonists
C. Phosphate derivatives