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 : 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 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 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 : 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 : Which of the following is a G protein coupled receptor: A. Muscarinic cholinergic receptor B. Nicotinic cholinergic receptor C. Glucocorticoid receptor D. Insulin receptor
Last Answer : A. Muscarinic cholinergic receptor
Description : The site of action of miotics for therapeutic effect in angle closure glaucoma is: A. Canal of Schlemm B. Ciliary body C. Ciliary muscle D. Sphincter pupillae muscle
Last Answer : D. Sphincter pupillae muscle
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 : 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
Description : If the dose-response curves of a drug for producing different actions are widely separated on the dose axis, the drug is: A. Highly potent B. Highly efficacious C. Highly toxic D. Highly selective
Last Answer : D. Highly selective
Description : The plasma half life of penicillin-G is longer in the new born because their: A. Plasma protein level is low B. Drug metabolizing enzymes are immature C. Glomerular filtration rate is low D. Tubular transport mechanisms are not well developed
Last Answer : D. Tubular transport mechanisms are not well developed
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 : The following is true of rivastigmine except: A. It is a relatively selective inhibitor of G1 isoform of acetylcholinesterase B. It has been found to retard disease progression in ... 's disease symptom score D. It enhances cerebral cholinergic transmission with only mild peripheral effect
Last Answer : B. It has been found to retard disease progression in Alzheimer's disease
Description : At the muscle end-plate, d-tubocurarine reduces the: A. Number of Na+ channels B. Duration for which the Na+ channels remain open C. Ion conductance of the open Na+ channel D. Frequency of Na+ channel opening
Last Answer : D. Frequency of Na+ channel opening
Description : Which of the following statements is true for lignocaine: A. It is an ester-linked local anaesthetic B. It is not likely to exhibit cross-sensitivity with procaine C. It has a shorter duration of action than procaine D. It is not a surface anaesthetic
Last Answer : B. It is not likely to exhibit cross-sensitivity with procaine
Description : Which of the following statements is not true of fixed dose combination formulations: A. They are more convenient B. Contraindication to one of the components does not contraindicate the formulation ... adjusted D. The time course of action of the different components may not be identical
Last Answer : B. Contraindication to one of the components does not contraindicate the formulation
Description : Phenytoin appears to derive its anticonvulsant action from: A. Selective inhibition of high frequency neuronal discharges B. Selective inhibition of epileptic focus C. Selective inhibition T-type Ca2+ current in brain cells D. Selective enhancement of inhibitory transmission in the brain
Last Answer : A. Selective inhibition of high frequency neuronal discharges
Description : Which adverse drug effect is more common in children than in adults: A. Isoniazid induced neuropathy B. Chlorpromazine induced muscle dystonia C. Digoxin induced cardiac arrhythmia D. Penicillin hypersensitivity
Last Answer : B. Chlorpromazine induced muscle dystonia
Description : The mechanism of antibacterial action of tetracycline involves (a) Binding to a component of the 50S ribosomal subunit (b) Inhibition of translocase activity (c) Blockade of binding of ... (d) Selective inhibition of ribosomal peptidyl transferases (e) Inhibition of DNA-dependent RNA polymerase
Last Answer : Ans: C
Description : Select the longer acting ocular beta blocker: A. Timolol B. Betaxolol C. Cartiolol D. Levobunolol
Last Answer : D. Levobunolol
Description : Pilocarpine reduces intraocular tension in open angle glaucoma by: A. Contracting sphincter pupillae B. Increasing tone of ciliary muscle C. Reducing aqueous formation D. Enhancing uveo-scleral outflow
Last Answer : B. Increasing tone of ciliary muscle
Description : Which of the following is an idiosyncratic adverse drug reaction: A. Muscle dystonia caused by triflupromazine B. Insomnia after taking pentobarbitone C. Precipitation of asthma by morphine D. Gum hyperplasia caused by phenytoin
Last Answer : B. Insomnia after taking pentobarbitone
Description : Which of the following adverse drug reactions is due to a specific genetic abnormality: A. Tetracycline induced sunburn like skin lesions B. Quinidine induced thrombocytopenia C. Metoclopramide induced muscle dystonia D. Primaquine induced massive haemolysis
Last Answer : D. Primaquine induced massive haemolysis
Description : Out of two anticholinesterases, drug X' is a tertiary amine while drug Y' is a quarternary ammonium compound. Then: A. Drug X' is likely to be more potent than Y' B. Drug X' will be more ... a miotic C. Drug Y' will be completely metabolized in the body D. Drug Y' will produce CNS effects
Last Answer : B. Drug ‘X’ will be more suitable to be used as a miotic
Description : The primary reason for a physician to prescribe human insulin is that: a) It has a faster onset of action than other insulins b) It has a shorter duration of action than other insulins c ... in preventing the complications of diabetes than animal insulins e) It is more sterile than other insolines.
Description : Interaction between the following pair of drugs can be avoided by making suitable adjustments: A. Levodopa and metoclopramide B. Furosemide and indomethacin C. Tetracyclines and ferrous sulfate D. Clonidine and chlorpromazine
Last Answer : C. Tetracyclines and ferrous sulfate
Description : Enalapril differs from captopril in that: A. It blocks angiotensin II receptors B. It does not produce cough as a side effect C. It is less liable to cause abrupt first dose hypotension D. It has a shorter duration of action
Last Answer : C. It is less liable to cause abrupt first dose hypotension
Description : The local anaesthetics having amide linkage differ from those having ester linkage in that the amidelinked local anaesthetics: A. Are not surface anaesthetics B. Have a shorter duration of action C. Are degraded in the plasma D. Do not show cross-sensitivity with esterlinked local anaesthetic
Last Answer : D. Do not show cross-sensitivity with esterlinked local anaesth
Description : Low concentration of bupivacaine is preferred for spinal / epidural obstetric analgesia because: A. It has a longer duration of action B. It can produce sensory blockade without paralysing abdominal muscles C. ... in maternal tissues so that less reaches the foetus D. All of the above are correct
Last Answer : D. All of the above are correct
Description : Which racial difference in response to drugs has been mentioned incorrectly below: A. Africans require higher concentration of atropine to dilate pupils B. Black races are more responsive ... SMON due to halogenated hydroxyquinolines D. Chloramphenicol induced aplastic anaemia is rare among Indians
Last Answer : B. Black races are more responsive to antihypertensive action of beta blockers
Description : A nonvolatile, highly lipid soluble drug is metabolized at a rate of 15% per hour. On intravenous injection it produces general anaesthesia for 10 min. Which process is responsible for termination of ... : A. Metabolism in liver B. Plasma protein binding C. Excretion by kidney D. Redistribution
Last Answer : D. Redistribution
Description : Ganglion blocking drugs are no longer used in therapeutics because: A. They have few and weak pharmacological actions B. They produce many side effects C. They are inactive by oral route D. They have short duration of action
Last Answer : A. They have potent antiovulatory action of their own
Last Answer : B. They produce many side effects