Description : The most efficacious inhibitor of catecholamine synthesis in the body is: A. α-methyl-p-tyrosine B. α-methyldopa C. α-methyl-norepinephrine D. Entacapone
Last Answer : A. α-methyl-p-tyrosine
Description : The most efficacious inhibitor of catecholamine synthesis in the body is (a) a - methyl – p - tyrosine (b) a - methyldopa (c) a - methyl - norepinephrine (d) Pyrogallol
Last Answer : Ans: A
Description : The rate limiting enzyme in the synthesis of catecholamines is: A. Tyrosine hydroxylase B. Dopa decarboxylase C. Dopamine β-hydroxylase D. Noradrenaline N-methyl transferase
Last Answer : A. Tyrosine hydroxylase
Description : The rate limiting step in catecholamine synthesis is catalysed by (A) Phenylalanine hydroxylase (B) Tyrosine hydroxylase (C) Dopa decarboxylase (D) Phenylethanolamine N-methyl transferase
Last Answer : Answer : B
Description : Betaxolol differs from timolol in that it: A. Is a β1 selective blocker B. Is more efficacious in glaucoma C. Produces less ocular side effects D. Is longer acting
Last Answer : A. Is a β1 selective blocker
Description : The biosynthesis of both Catecholamine and serotonin require (A) Tyrosine hydroxylase (B) N-methyl transferase (C) Aromatic amino acid decarboxylase (D) Tryptophan pyrrolase
Description : Methyldopa lowers BP by: A. Inhibiting dopa decarboxylase in adrenergic nerve endings B. Generating α-methyl noradrenaline in brain which reduces sympathetic tone C. Generating α-methyl ... as a false transmitter in peripheral adrenergic nerve endings D. Activating vascular dopamine receptors
Last Answer : B. Generating α-methyl noradrenaline in brain which reduces sympathetic tone
Description : Reactivation of cholinesterase enzyme occurs on hydrolysis of the inhibitor by the same enzyme molecule in case of the following anticholinesterase: A. Edrophonium B. Neostigmine C. Dyflos D. Tacrine
Last Answer : B. Neostigmine
Description : The following inhibitor binds only to the ani-onic site of the cholinesterase enzyme: A. Neostigmine B. Physostigmine C. Edrophonium D. Dyflos
Last Answer : C. Edrophonium
Description : Tyrosine is required for the synthesis of all of the following except (A) Melatonin (B) Epinephrine (C) Norepinephrine (D) Thyroxine 222 MCQs IN BIOCHEMISTRY
Last Answer : Answer : A
Description : Sildenafil is contraindicated in patients taking the following class of drugs: A. α-adrenergic blockers B. β-adrenergic blockers C. Organic nitrates D. Angiotensin converting enzyme inhibitors
Last Answer : C. Organic nitrates
Description : The primary reason for preferring phentolamine as the α adrenergic blocker for performing diagnostic test for pheochromocytoma is: A. It produces rapid and short lasting α-adrenergic blockade B. It equally ... It is the most potent α blocker D. It has no additional β adrenergic blocking property
Last Answer : A. It produces rapid and short lasting α-adrenergic blockade
Description : The drug which produces vasoconstriction despite being an α adrenergic blocker is: A. Phenoxybenzamine B. Ergotamine C. Dihydroergotoxine D. Tolazoline
Last Answer : B. Ergotamine
Description : The nonselective α adrenergic blockers produce the following actions except: A. Postural hypotension B. Bradycardia C. Miosis D. Inhibition of ejaculation
Last Answer : B. Bradycardia
Description : Ephedrine is similar to adrenaline in the following feature: A. Potency B. Inability to penetrate blood-brain barrier C. Duration of action D. Producing both α and β adrenergic effects
Last Answer : D. Producing both α and β adrenergic effects
Description : Dopaminergic D1 and D2 as well as adrenergic α and β1, but not β2 receptors are activated by: A. Dopamine B. Dobutamine C. Methoxamine D. Phenylephrine
Last Answer : A. Dopamine
Description : The following action of adrenaline is mediated by both α and β receptors producing the same directional effect: A. Cardiac stimulation B. Intestinal relaxation C. Dilatation of pupil D. Bronchodilatation
Last Answer : B. Intestinal relaxation
Description : Select the β -adrenergic blocker that has additional α 1 blocking, vasodilator and antioxidant properties: A. Carvedilol B. Celiprolol C. Acebutolol D. Metoprolol
Last Answer : A. Carvedilol
Description : Which of the following is a selective α 1A receptor blocker that affords symptomatic relief in benign prostatic hypertrophy without producing significant fall in blood pressure: A. Terazosin B. Doxazosin C. Trimazosin D. Tamsulosin
Last Answer : D. Tamsulosin
Description : Dopaminergic D1 and D2 as well as adrenergic α and β 1, but not β 2 receptors are activated by: A. Dopamine B. Dobutamine C. Methoxamine D. Phenylephrine
Description : The following sympathomimetic amine has agonistic action on α 1 + α 2 + β 1 + β 3 adrenoceptors, but not on β 2 receptors: A. Adrenaline B. Noradrenaline C. Isoprenaline D. Phenylephrine
Last Answer : B. Noradrenaline
Description : The anticholinesterase action of edrophonium is short lasting because termination of its action depends on: A. Dissociation and diffusion of the drug from the enzyme B. Hydrolysis of the drug by the enzyme C. Synthesis of fresh enzyme molecules D. A combination of the above three processes
Last Answer : A. Dissociation and diffusion of the drug from the enzyme
Description : The following is a reversible and selective MAO-A inhibitor: A. Bupropion B. Entacapone C. Moclobemide D. Selegiline
Last Answer : C. Moclobemide
Description : For Catecholamine biosynthesis the rate limiting enzyme is (A) DOPA decarboxylase (B) DOPAMINE β-hydroxylase (C) Tyrosine hydroxylase (D) Phenylalanine hydroxylase
Last Answer : Answer : C
Description : Choose the most potent and most efficacious LDLcholesterol lowering HMG-CoA reductase inhibitor: A. Lovastatin B. Simvastatin C. Pravastatin D. Atorvastatin
Last Answer : D. Atorvastatin
Description : Which of the following is an efficacious antiinflammatory drug but a relatively weak inhibitor of cyclooxygenase: A. Nimesulide B. Paracetamol C. Ketoprofen D. Indomethacin
Last Answer : A. Nimesulide
Description : Following events occur in the cytoplasm and not inside storage vesicles, except (a) Conversion of tyrosine to dopa (b) Conversion of dopa to dopamine (c) Conversion of dopamine to norepinephrine (d) Conversion of dopamine to 3,4 dihydroxy phenyl acetic acid
Last Answer : Ans: C
Description : Beta adrenergic blockers lower intraocular tension by: A. Down regulating adenylyl cyclase in ciliary body through reduced activation of β2 adrenoceptors B. Constricting ciliary blood vessels ... action on trabecular meshwork D. Reducing aqueous formation unrelated to beta adrenoceptor mediation
Last Answer : A. Down regulating adenylyl cyclase in ciliary body through reduced activation of β2 adrenoceptors
Description : Norepinephrine binds mainly to (A) α-Adrenergic receptors (B) β-Adrenergic receptrors (C) Muscarinic receptors (D) Nicotinic receptors
Description : Select the β-adrenergic blocker that has additional α1 blocking, vasodilator and antioxidant properties: A. Carvedilol B. Celiprolol C. Acebutolol D. Metoprolol
Last Answer : C. Acebutolol
Description : In a patient of myocardial infarction, β adrenergic blockers are used with the following aim/aims: A. To reduce the incidence of reinfarction B. To prevent cardiac arrhythmias C. To limit size of the infarct D. All of the above
Last Answer : D. All of the above
Description : Select the β adrenergic blocker that is primarily eliminated unchanged by renal excretion: A. Propranolol B. Metoprolol C. Esmolol D. Atenolol
Last Answer : D. Atenolol
Description : The following is not a feature of cardioselective beta blockers, when compared to propranolol: A. They are ineffective in suppressing muscle tremor B. They are safer in diabetics C. They are less likely to cause bradycardia D. They are less likely to worsen Raynaud’s disease
Last Answer : C. They are less likely to cause bradycardia
Description : Esmolol has the following features except: A. Rapidly developing, shortlasting β adrenergic blockade B. Cardioselectivity of action C. Intrinsic sympathomimetic activity D. Suitability for intraoperative use
Last Answer : C. Intrinsic sympathomimetic activity
Description : Select the ultrashort acting cardioselective β adrenergic blocker: A. Bisoprolol B. Timolol C. Sotalol D. Esmolol
Last Answer : D. Esmolol
Description : β-adrenergic blockers are indicated in the following conditions except: A. Hypertrophic cardiomyopathy B. Congestive heart failure C. Vasospastic angina pectoris D. Dissecting aortic aneurysm
Last Answer : C. Vasospastic angina pectoris
Description : The following disease is worsened by propranolol: A. Glaucoma B. Raynaud’s disease C. Benign prostatic hypertrophy D. Parkinsonism
Last Answer : B. Raynaud’s disease
Description : Select the drug which can impair carbohydrate tolerance in prediabetics but prolongs insulin hypoglycaemia: A. Salbutamol B. Propranolol C. Prazosin D. Nifedipine
Last Answer : B. Propranolol
Description : The β adrenergic blocker having β1 selectivity, intrinsic sympathomimetic activity and membrane stabilizing property is: A. Carvedilol B. Atenolol C. Acebutolol D. Metoprolol
Description : Select the drug which is administered orally for erectile dysfunction in men: A. Yohimbine B. Papaverine C. Alprostadil D. Sildenafil
Last Answer : D. Sildenafil
Description : What is true of sildenafil: A. It enhances sexual enjoyment in normal men B. It delays ejaculation C. It improves penile tumescence in men with erectile dysfunction D. It blocks cavernosal α2 adrenoceptors
Last Answer : C. It improves penile tumescence in men with erectile dysfunction
Description : Which of the following is a selective α1A receptor blocker that affords symptomatic relief in benign prostatic hypertrophy without producing significant fall in blood pressure: A. Terazosin B. Doxazosin C. Trimazosin D. Tamsulosin
Description : The bladder trigone and prostatic muscles are relaxed by: A. Adrenergic α1 agonists B. Adrenergic α1 antagonists C. Adrenergic α2 agonists D. Adrenergic α2 antagonists
Last Answer : B. Adrenergic α1 antagonists
Description : Adrenaline injected with a local anaesthetic: A. Reduces local toxicity of the local anaesthetic B. Reduces systemic toxicity of the local anaesthetic C. Shortens duration of local anaesthesia D. Makes the injection less painful
Last Answer : B. Reduces systemic toxicity of the local anaesthetic