USMLE STEP 1 Pharmacology Exam Questions And Answers Verified 100% Correct

USMLE STEP 1 Pharmacology Exam Questions And Answers Verified 100% Correct 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) Pyridostigmine -Anticholinesterse - increases ACh -Increases muscle strength -Used in myasthenia gravis (long acting) -Does not penetrate CNS Atropine -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 Benztropine -Muscarinic antagonist -Works in CNS -Used in Parkinson disease and acute dystonia