Edrophonium is more suitable for differentiating myasthenic crisis from cholinergic crisis because of its:
A. Shorter duration of action
B. Longer duration of action
C. Direct action on muscle end-plate
D. Selective inhibition of true cholinesterase

1 Answer

Answer :

A. Shorter duration of action

Related questions

Description : Edrophonium is more suitable for differentiating myasthenic crisis from cholinergic crisis because of its: A. Shorter duration of action B. Longer duration of action C. Direct action on muscle end-plate D. Selective inhibition of true cholinesterase

Last Answer : A. Shorter duration of action

Description : Neostigmine is preferred over physostigmine for treating myasthenia gravis because: A. It is better absorbed orally B. It has longer duration of action C. It has additional direct agonistic action on nicotinic receptors at the muscle end plate D. It penetrates blood-brain barrier

Last Answer : C. It has additional direct agonistic action on nicotinic receptors at the muscle end plate

Description : The mechanism by which neostigmine improves contraction of myasthenic muscle involves: A. Repetitive binding of the acetylcholine molecules to the same receptors at the muscle endplate B. Diffusion of ... Activation of motor end-plate receptors by neostigmine molecules themselves D. All of the above

Last Answer : D. All of the above

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 : Pseudocholinesterase differs from true cholinesterase in that: A. It does not hydrolyse acetylcholine B. It hydrolyses acetylcholine at a slower rate C. It is more susceptible to inhibition by physostigmine D. It is the only form of circulating cholinesterase

Last Answer : B. It hydrolyses acetylcholine at a slower rate

Description : Pseudocholinesterase differs from true cholinesterase in that: A. It does not hydrolyse acetylcholine B. It hydrolyses acetylcholine at a slower rate C. It is more susceptible to inhibition by physostigmine D. It is the only form of circulating cholinesterase

Last Answer : B. It hydrolyses acetylcholine at a slower rate

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 : Neostigmine is preferred over physostigmine for treating myasthenia gravis because: A. It is better absorbed orally B. It has longer duration of action C. It has additional direct agonistic action on nicotinic receptors at the muscle end plate D. It penetrates blood-brain barrier

Last Answer : C. It has additional direct agonistic action on nicotinic receptors at the muscle end plate

Description : The smooth muscle structure that is relaxed by cholinergic drugs is: A. Colon B. Gastric fundus C. Major bronchi D. Bladder trigone

Last Answer : D. Bladder trigone

Description : Pyridostigmine differs from neostigmine in that: A. It is more potent orally B. It is longer acting C. It produces less muscarinic side effects D. It does not have any direct action on NM receptors

Last Answer : B. It is longer acting

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 : Choose the correct statement about drotaverine: A. It is a smooth muscle antispasmodic acting by non-anticholinergic mechanisms B. It is a papaverine congener used in peripheral vascular diseases C. It ... used to control diarrhoea D. It is a M1/M3 selective antagonist used for spastic constipation

Last Answer : A. It is a smooth muscle antispasmodic acting by non-anticholinergic mechanisms

Description : Cholinergic muscarinic receptor stimulation produces the following effects except: A. Sweating B. Rise in blood pressure C. Bradycardia D. Urination

Last Answer : B. Rise in blood pressure

Description : Muscarinic cholinergic receptors: A. Are located only on parasympathetically innervated effector cells B. Mediate responses by opening an intrinsic Na+ ion channel C. Are present on vascular endothelium which has no cholinergic nerve supply D. Predominate in the autonomic ganglia

Last Answer : C. Are present on vascular endothelium which has no cholinergic nerve supply

Description : The major postjunctional cholinergic receptor is of the muscarinic type at the following site: A. Postganglionic parasympathetic B. Adrenal medulla C. Autonomic ganglia D. Neuromuscular junction

Last Answer : A. Postganglionic parasympathetic

Description : The major postjunctional cholinergic receptor is of the muscarinic type at the following site: A. Postganglionic parasympathetic B. Adrenal medulla C. Autonomic ganglia D. Neuromuscular junction

Last Answer : A. Postganglionic parasympathetic

Description : The mechanism by which neostigmine improves contraction of myasthenic muscle involves: A. Repetitive binding of the acetylcholine molecules to the same receptors at the muscle endplate B. Diffusion of ... Activation of motor end-plate receptors by neostigmine molecules themselves D. All of the above

Last Answer : D. All of the above

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 : 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 : The organophosphates produce irreversible inhibition of cholinesterase because: A. They bind to an allosteric site of the enzyme resulting in unfavourable conformation of esteratic site to bind ... degradation of enzyme molecules D. They are neither metabolized nor excreted from the body

Last Answer : B. Regeneration time of the phosphorylated enzyme is longer than the turnover time of the enzyme molecules

Description : The organophosphates produce irreversible inhibition of cholinesterase because: A. They bind to an allosteric site of the enzyme resulting in unfavourable conformation of esteratic site to bind ... degradation of enzyme molecules D. They are neither metabolized nor excreted from the body

Last Answer : B. Regeneration time of the phosphorylated enzyme is longer than the turnover time of the enzyme molecules

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 : 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 : 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

Last Answer : D. Tamsulosin

Description : Choose the drug which is used as a short-term inotropic in severe congestive heart failure and has selective adrenergic β1 agonistic activity but no dopaminergic agonistic activity: A. Dopamine B. Dobutamine C. Amrinone D. Salmeterol

Last Answer : B. Dobutamine

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 : Choose the drug which is used as a short-term inotropic in severe congestive heart failure and has selective adrenergic β 1 agonistic activity but no dopaminergic agonistic activity: A. Dopamine B. Dobutamine C. Amrinone D. Salmeterol

Last Answer : B. Dobutamine

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

Description : Neostigmine is beneficial in cobra envenomation because: A. It binds to and inactivates cobra toxin B. It reverses coma due to cobra toxin C. It counteracts the cardio-depressant action of cobra toxin D. It antagonizes the paralysing action of cobra toxin

Last Answer : D. It antagonizes the paralysing action of cobra toxin

Description : Neostigmine is beneficial in cobra envenomation because: A. It binds to and inactivates cobra toxin B. It reverses coma due to cobra toxin C. It counteracts the cardio-depressant action of cobra toxin D. It antagonizes the paralysing action of cobra toxin

Last Answer : D. It antagonizes the paralysing action of cobra toxin

Description : The following is true of fenfluramine except: A. It lacks CNS stimulant action B. Its use has been associated with cardiac abnormalities and pulmonary hypertension C. It causes weight loss independent of reduced food intake D. It enhances serotonergic transmission in the brain

Last Answer : C. It causes weight loss independent of reduced food intake

Description : Hyoscine differs from atropine in that it: A. Exerts depressant effects on the CNS at relatively low doses B. Exerts more potent effects on the heart than on the eye C. Is longer acting D. Has weaker antimotion sickness activity

Last Answer : A. Exerts depressant effects on the CNS at relatively low doses

Description : Select the longer acting ocular beta blocker: A. Timolol B. Betaxolol C. Cartiolol D. Levobunolol

Last Answer : D. Levobunolol

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 : Low doses of adrenaline dilate the following vascular bed: A. Cutaneous B. Mucosal C. Renal D. Skeletal muscle

Last Answer : D. Skeletal muscle

Description : The organ most sensitive to actions of atropine is: A. Gastric glands B. Salivary glands C. Urinary bladder muscle D. Heart

Last Answer : B. Salivary glands

Description : Which of the following organs is innervated only by parasympathetic nerves: A. Iris muscles B. Ciliary musclele C. Sweat glands D. Splenic capsu

Last Answer : B. Ciliary musclele

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 : Low doses of adrenaline dilate the following vascular bed: A. Cutaneous B. Mucosal C. Renal D. Skeletal muscle

Last Answer : D. Skeletal muscle

Description : Which of the following organs is innervated only by parasympathetic nerves: A. Iris muscles B. Ciliary muscle C. Sweat glands D. Splenic capsule

Last Answer : B. Ciliary muscle

Description : Omeprazole exerts practically no other action except inhibition of gastric acid secretion because: A. It transforms into the active cationic forms only in the acidic pH of the gastric juice B. Its ... forms are unable to diffuse out from the gastric parietal cell canaliculi D. All of the above

Last Answer : D. All of the above

Description : The most suitable mydriatic for a patient of corneal ulcer is: A. Atropine sulfate B. Homatropine C. Cyclopentolate D. Tropicamide

Last Answer : A. Atropine sulfate

Description : The following are true about the autonomic nervous system: a. the postganglionic neurones are largely unmyelinated b. all preganglionic neurones are cholinergic c. the preganglionic neurones of ... parasympathetic nervous system d. the parasympathetic outflow is only found in the cranial nerves

Last Answer : the postganglionic neurones are largely unmyelinated

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 : 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 : The following sympathomimetic amine has agonistic action on α1 + α2 + β1 + β3 adrenoceptors, but not on β2 receptors: A. Adrenaline B. Noradrenaline C. Isoprenaline D. Phenylephrine

Last Answer : B. Noradrenaline

Description : The principal process which terminates the action of noradrenaline released from adrenergic nerve ending is: A. Degradation by MAO B. Methylation by COMT C. Axonal uptake D. Extraneuronal uptake

Last Answer : C. Axonal uptake

Description : Which of the following mydriatics has the fastest and briefest action: A. Atropine B. Homatropine C. Tropicamide D. Cyclopentolate

Last Answer : C. Tropicamide