USMLE STEP 1 Pharmacology Quiz Bank with complete solutions | Latest 2023/2024

USMLE STEP 1 Pharmacology Quiz Bank with complete solutions | Latest 2023/2024 What are the major functions of the α1 receptor? -- 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? -- Decrease sympathetic outflow, decrease insulin release, decrease lipolysis, increase platelet aggregation, decrease aqueous humor production What are the major functions of the β1 receptor? -- Increase heart rate, increase contractility, increase renin release, increase lipolysis What are the major functions of the β2 receptor? -- 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? -- CNS, enteric nervous system What are the major functions of the M2 receptor? -- Decrease heart rate and contractility of atria What are the major functions of the M3 receptor? -- 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? -- Relaxes renal vascular smooth muscle What are the major functions of the D2 receptor? -- Modulates transmitter release, especially in the brain What are the major functions of the H1 receptor? -- Increase nasal and bronchial mucus production, increase vascular permeability, contraction of bronchioles, pruritis, pain What are the major functions of the H2 receptor? -- Increase gastric acid secretion What are the major functions of the V1 receptor? -- Increase vascular smooth muscle contraction What are the major functions of the V2 receptor? -- Increase H2O permeability and reabsorption in collecting tubules of kidney (V2 is found in the "2" kidneys) What receptors are associate with Gq? -- H1, α1, V1, M1, and M3 What receptors are associated with Gs? -- H2, B1, B2, V2, D1 What receptors are associated with Gi? -- M2, α2, D2 Bethanechol -- -Direct cholinergic agonist -Activates bowel and bladder smooth muscle -Used in postoperative and neurogenic ileus -Resistant to AChE Carbachol -- -Direct cholinergic agonist -Carbon copy of acetylcholine -Constricts pupils and relieves intraocular pressure in glaucoma Methacholine -- -Direct cholinergic agonist -Stimulates muscarinic receptors in airways when inhaled -Used as a challenge test for diagnosis of asthma Pilocarpine -- -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 -- -Anticholinesterse - increases ACh -Alzheimer disease Galantamine -- -Anticholinesterse - increases ACh -Alzheimer disease Rivastigmine -- -Anticholinesterse - increases ACh -Alzheimer disease Edrophonium -- -Anticholinesterse - increases ACh -Historically used to diagnose myasthenia gravis (MG is now diagnosed by anti-AChR Ab test. Neostigmine -- -Anticholinesterse - increases ACh -Used in postoperative and neurogenic ileus and urinary retention, myasthenia gravis, and postoperative reversal of neuromuscular junction blockade Physostigmine -- -Anticholinesterse - increases ACh -Used in anticholinergic toxicity -Crosses the blood-brain barrier (CNS)