Pharmacology USMLE step 1
What are the major functions of the α1 receptor? ------- ✔ CORRECT ANSWER ✓✓Increase
vascular smooth muscle contraction, increase pupillary dilator muscle contraction (mydriasis),
increase intestinal and bladder sphincter muscle contraction
What are the major functions of the α2 receptor? ------- ✔ CORRECT ANSWER ✓✓Decrease
sympathetic outflow, decrease insulin release, decrease lipolysis, increase platelet aggregation,
decrease aqueous humor production
What are the major functions of the β1 receptor? ------- ✔ CORRECT ANSWER ✓✓Increase
heart rate, increase contractility, increase renin release, increase lipolysis
What are the major functions of the β2 receptor? ------- ✔ CORRECT ANSWER ✓✓Vasodilation,
bronchodilation, increase lipolysis, increase insulin release, decrease uterine tone (tocolysis),
ciliary muscle relaxation, increase aqueous humor production
What are the major functions of the M1 receptor? ------- ✔ CORRECT ANSWER ✓✓CNS, enteric
nervous system
What are the major functions of the M2 receptor? ------- ✔ CORRECT ANSWER ✓✓Decrease
heart rate and contractility of atria
What are the major functions of the M3 receptor? ------- ✔ CORRECT ANSWER ✓✓Increase
exocrine gland secretions (e.g., lacrimal, salivary, gastric acid), increase gut peristalsis, increase
bladder contraction, increase bronchoconstriction, pupillary sphincter muscle contraction
(miosis), ciliary muscle contraction (accommodation)
, What are the major functions of the D1 receptor? ------- ✔ CORRECT ANSWER ✓✓Relaxes renal
vascular smooth muscle
What are the major functions of the D2 receptor? ------- ✔ CORRECT ANSWER ✓✓Modulates
transmitter release, especially in the brain
What are the major functions of the H1 receptor? ------- ✔ CORRECT ANSWER ✓✓Increase
nasal and bronchial mucus production, increase vascular permeability, contraction of
bronchioles, pruritis, pain
What are the major functions of the H2 receptor? ------- ✔ CORRECT ANSWER ✓✓Increase
gastric acid secretion
What are the major functions of the V1 receptor? ------- ✔ CORRECT ANSWER ✓✓Increase
vascular smooth muscle contraction
What are the major functions of the V2 receptor? ------- ✔ CORRECT ANSWER ✓✓Increase H2O
permeability and reabsorption in collecting tubules of kidney (V2 is found in the "2" kidneys)
What receptors are associate with Gq? ------- ✔ CORRECT ANSWER ✓✓H1, α1, V1, M1, and M3
What receptors are associated with Gs? ------- ✔ CORRECT ANSWER ✓✓H2, B1, B2, V2, D1
What receptors are associated with Gi? ------- ✔ CORRECT ANSWER ✓✓M2, α2, D2
Bethanechol ------- ✔ CORRECT ANSWER ✓✓-Direct cholinergic agonist
-Activates bowel and bladder smooth muscle
,-Used in postoperative and neurogenic ileus
-Resistant to AChE
Carbachol ------- ✔ CORRECT ANSWER ✓✓-Direct cholinergic agonist
-Carbon copy of acetylcholine
-Constricts pupils and relieves intraocular pressure in glaucoma
Methacholine ------- ✔ CORRECT ANSWER ✓✓-Direct cholinergic agonist
-Stimulates muscarinic receptors in airways when inhaled
-Used as a challenge test for diagnosis of asthma
Pilocarpine ------- ✔ CORRECT ANSWER ✓✓-Direct cholinergic agonist
-Contracts ciliary muscle of eye (open angle glaucoma), contracts pupillary sphincter (closed
angle glaucoma)
-Potent stimulator of sweat, tears and saliva
-AChE resistant
Donepezil ------- ✔ CORRECT ANSWER ✓✓-Anticholinesterse - increases ACh
-Alzheimer disease
Galantamine ------- ✔ CORRECT ANSWER ✓✓-Anticholinesterse - increases ACh
-Alzheimer disease
Rivastigmine ------- ✔ CORRECT ANSWER ✓✓-Anticholinesterse - increases ACh
-Alzheimer disease
, Edrophonium ------- ✔ CORRECT ANSWER ✓✓-Anticholinesterse - increases ACh
-Historically used to diagnose myasthenia gravis (MG is now diagnosed by anti-AChR Ab test.
Neostigmine ------- ✔ CORRECT ANSWER ✓✓-Anticholinesterse - increases ACh
-Used in postoperative and neurogenic ileus and urinary retention, myasthenia gravis, and
postoperative reversal of neuromuscular junction blockade
Physostigmine ------- ✔ CORRECT ANSWER ✓✓-Anticholinesterse - increases ACh
-Used in anticholinergic toxicity
-Crosses the blood-brain barrier (CNS)
Pyridostigmine ------- ✔ CORRECT ANSWER ✓✓-Anticholinesterse - increases ACh
-Increases muscle strength
-Used in myasthenia gravis (long acting)
-Does not penetrate CNS
Atropine ------- ✔ CORRECT ANSWER ✓✓-Muscarinic antagonist
-Used in bradycardia and for ophthalmic applications
-Also used as antidote for cholinesterase inhibitor poisoning
-Actions include increase pupil dilation, cycloplegia, decreased airway secretions, decreased
acid secretions, decreased gut motility, decreased bladder urgency in cystitis
-Toxicity: increased body temp (due to decreased sweating), rapid pulse, dry mouth, dry and
flushed skin, cycloplegia, constipation, disorientation;
-Can cause acute angle-closure glaucoma in elderly (due to mydriasis), urinary retention in men
with prostatic hyperplasia, and hyperthermia in infants
-See also homatropine and tropicamide
What are the major functions of the α1 receptor? ------- ✔ CORRECT ANSWER ✓✓Increase
vascular smooth muscle contraction, increase pupillary dilator muscle contraction (mydriasis),
increase intestinal and bladder sphincter muscle contraction
What are the major functions of the α2 receptor? ------- ✔ CORRECT ANSWER ✓✓Decrease
sympathetic outflow, decrease insulin release, decrease lipolysis, increase platelet aggregation,
decrease aqueous humor production
What are the major functions of the β1 receptor? ------- ✔ CORRECT ANSWER ✓✓Increase
heart rate, increase contractility, increase renin release, increase lipolysis
What are the major functions of the β2 receptor? ------- ✔ CORRECT ANSWER ✓✓Vasodilation,
bronchodilation, increase lipolysis, increase insulin release, decrease uterine tone (tocolysis),
ciliary muscle relaxation, increase aqueous humor production
What are the major functions of the M1 receptor? ------- ✔ CORRECT ANSWER ✓✓CNS, enteric
nervous system
What are the major functions of the M2 receptor? ------- ✔ CORRECT ANSWER ✓✓Decrease
heart rate and contractility of atria
What are the major functions of the M3 receptor? ------- ✔ CORRECT ANSWER ✓✓Increase
exocrine gland secretions (e.g., lacrimal, salivary, gastric acid), increase gut peristalsis, increase
bladder contraction, increase bronchoconstriction, pupillary sphincter muscle contraction
(miosis), ciliary muscle contraction (accommodation)
, What are the major functions of the D1 receptor? ------- ✔ CORRECT ANSWER ✓✓Relaxes renal
vascular smooth muscle
What are the major functions of the D2 receptor? ------- ✔ CORRECT ANSWER ✓✓Modulates
transmitter release, especially in the brain
What are the major functions of the H1 receptor? ------- ✔ CORRECT ANSWER ✓✓Increase
nasal and bronchial mucus production, increase vascular permeability, contraction of
bronchioles, pruritis, pain
What are the major functions of the H2 receptor? ------- ✔ CORRECT ANSWER ✓✓Increase
gastric acid secretion
What are the major functions of the V1 receptor? ------- ✔ CORRECT ANSWER ✓✓Increase
vascular smooth muscle contraction
What are the major functions of the V2 receptor? ------- ✔ CORRECT ANSWER ✓✓Increase H2O
permeability and reabsorption in collecting tubules of kidney (V2 is found in the "2" kidneys)
What receptors are associate with Gq? ------- ✔ CORRECT ANSWER ✓✓H1, α1, V1, M1, and M3
What receptors are associated with Gs? ------- ✔ CORRECT ANSWER ✓✓H2, B1, B2, V2, D1
What receptors are associated with Gi? ------- ✔ CORRECT ANSWER ✓✓M2, α2, D2
Bethanechol ------- ✔ CORRECT ANSWER ✓✓-Direct cholinergic agonist
-Activates bowel and bladder smooth muscle
,-Used in postoperative and neurogenic ileus
-Resistant to AChE
Carbachol ------- ✔ CORRECT ANSWER ✓✓-Direct cholinergic agonist
-Carbon copy of acetylcholine
-Constricts pupils and relieves intraocular pressure in glaucoma
Methacholine ------- ✔ CORRECT ANSWER ✓✓-Direct cholinergic agonist
-Stimulates muscarinic receptors in airways when inhaled
-Used as a challenge test for diagnosis of asthma
Pilocarpine ------- ✔ CORRECT ANSWER ✓✓-Direct cholinergic agonist
-Contracts ciliary muscle of eye (open angle glaucoma), contracts pupillary sphincter (closed
angle glaucoma)
-Potent stimulator of sweat, tears and saliva
-AChE resistant
Donepezil ------- ✔ CORRECT ANSWER ✓✓-Anticholinesterse - increases ACh
-Alzheimer disease
Galantamine ------- ✔ CORRECT ANSWER ✓✓-Anticholinesterse - increases ACh
-Alzheimer disease
Rivastigmine ------- ✔ CORRECT ANSWER ✓✓-Anticholinesterse - increases ACh
-Alzheimer disease
, Edrophonium ------- ✔ CORRECT ANSWER ✓✓-Anticholinesterse - increases ACh
-Historically used to diagnose myasthenia gravis (MG is now diagnosed by anti-AChR Ab test.
Neostigmine ------- ✔ CORRECT ANSWER ✓✓-Anticholinesterse - increases ACh
-Used in postoperative and neurogenic ileus and urinary retention, myasthenia gravis, and
postoperative reversal of neuromuscular junction blockade
Physostigmine ------- ✔ CORRECT ANSWER ✓✓-Anticholinesterse - increases ACh
-Used in anticholinergic toxicity
-Crosses the blood-brain barrier (CNS)
Pyridostigmine ------- ✔ CORRECT ANSWER ✓✓-Anticholinesterse - increases ACh
-Increases muscle strength
-Used in myasthenia gravis (long acting)
-Does not penetrate CNS
Atropine ------- ✔ CORRECT ANSWER ✓✓-Muscarinic antagonist
-Used in bradycardia and for ophthalmic applications
-Also used as antidote for cholinesterase inhibitor poisoning
-Actions include increase pupil dilation, cycloplegia, decreased airway secretions, decreased
acid secretions, decreased gut motility, decreased bladder urgency in cystitis
-Toxicity: increased body temp (due to decreased sweating), rapid pulse, dry mouth, dry and
flushed skin, cycloplegia, constipation, disorientation;
-Can cause acute angle-closure glaucoma in elderly (due to mydriasis), urinary retention in men
with prostatic hyperplasia, and hyperthermia in infants
-See also homatropine and tropicamide
