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

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
by

1 Answer

Answer :

A. Dissociation and diffusion of the drug from the enzyme
by

Related questions

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

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

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

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

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

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

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

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

Induction of drug metabolizing enzymes involves: A. A conformational change in the enzyme protein to favour binding of substrate molecules B. Expression of enzyme molecules on the surface of hepatocytes C. Enhanced transport of substrate molecules into hepatocytes D. Increased synthesis of enzyme protein

Description : Induction of drug metabolizing enzymes involves: A. A conformational change in the enzyme protein to favour binding of substrate molecules B. Expression of enzyme molecules on the surface of ... C. Enhanced transport of substrate molecules into hepatocytes D. Increased synthesis of enzyme protein

Last Answer : D. Increased synthesis of enzyme protein

Induction of drug metabolizing enzymes involves: A. A conformational change in the enzyme protein to favour binding of substrate molecules B. Expression of enzyme molecules on the surface of hepatocytes C. Enhanced transport of substrate molecules into hepatocytes D. Increased synthesis of enzyme protein

Description : Induction of drug metabolizing enzymes involves: A. A conformational change in the enzyme protein to favour binding of substrate molecules B. Expression of enzyme molecules on the surface of ... C. Enhanced transport of substrate molecules into hepatocytes D. Increased synthesis of enzyme protein

Last Answer : D. Increased synthesis of enzyme protein

The following inhibitor binds only to the ani-onic site of the cholinesterase enzyme: A. Neostigmine B. Physostigmine C. Edrophonium D. Dyflos

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

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 its action: A. Metabolism in liver B. Plasma protein binding C. Excretion by kidney D. Redistribution

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

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 its action: A. Metabolism in liver B. Plasma protein binding C. Excretion by kidney D. Redistribution

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

3 Diffusion of drugs across cell membrane: A. Is dependent upon metabolic activity of the cell B. Is competitively inhibited by chemically related drugs C. Is affected by extent of ionization of drug molecules D. Exhibits saturation kinetics

Description : 3 Diffusion of drugs across cell membrane: A. Is dependent upon metabolic activity of the cell B. Is competitively inhibited by chemically related drugs C. Is affected by extent of ionization of drug molecules D. Exhibits saturation kinetics

Last Answer : C. Is affected by extent of ionization of drug molecules

The enzyme amino acyl tRNA synthetase is involved in (A) Dissociation of discharged tRNA from 80S ribosome (B) Charging of tRNA with specific amino acids (C) Termination of protein synthesis (D) Nucleophilic attack on esterified carboxyl group of peptidyl tRNA

Description : The enzyme amino acyl tRNA synthetase is involved in (A) Dissociation of discharged tRNA from 80S ribosome (B) Charging of tRNA with specific amino acids (C) Termination of protein synthesis (D) Nucleophilic attack on esterified carboxyl group of peptidyl tRNA

Last Answer : Answer : B

Which of the following is a relatively cerebroselective anticholinesterase found to afford symptomatic improvement in Alzheimer's disease: A. Donepezil B. Gemfibrozil C. Pyridostigmine D. Pyritinol

Description : Which of the following is a relatively cerebroselective anticholinesterase found to afford symptomatic improvement in Alzheimer's disease: A. Donepezil B. Gemfibrozil C. Pyridostigmine D. Pyritinol

Last Answer : A. Donepezil

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 acetylcholine B. Regeneration time of the phosphorylated enzyme is longer than the turnover time of the enzyme molecules C. Phosphorylation results in rapid degradation of enzyme molecules D. They are neither metabolized nor excreted from the body

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

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 acetylcholine released from motor nerve endings to a wider area activating neighbouring receptors C. Activation of motor end-plate receptors by neostigmine molecules themselves D. All of the above

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

The most important factor which governs diffusion of drugs across capillaries other than those in the brain is: A. Blood flow through the capillary B. Lipid solubility of the drug C. pKa value of the drug D. pH of the medium

Description : The most important factor which governs diffusion of drugs across capillaries other than those in the brain is: A. Blood flow through the capillary B. Lipid solubility of the drug C. pKa value of the drug D. pH of the medium

Last Answer : A. Blood flow through the capillary

The most important factor which governs diffusion of drugs across capillaries other than those in the brain is: A. Blood flow through the capillary B. Lipid solubility of the drug C. pKa value of the drug D. pH of the medium

Description : The most important factor which governs diffusion of drugs across capillaries other than those in the brain is: A. Blood flow through the capillary B. Lipid solubility of the drug C. pKa value of the drug D. pH of the medium

Last Answer : A. Blood flow through the capillary

A fixed dose combination preparation meant for internal use must not contain the following class of drug: A. Thiazide diuretic B. Fluoroquinolone antimicrobial C. Corticosteroid D. H2 blocker

Description : A fixed dose combination preparation meant for internal use must not contain the following class of drug: A. Thiazide diuretic B. Fluoroquinolone antimicrobial C. Corticosteroid D. H2 blocker

Last Answer : C. Corticosteroid

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 C. The dose of any one component cannot be independently adjusted D. The time course of action of the different components may not be identical

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

The antagonism between adrenaline and histamine is called ‘physiological antagonism’ because: A. Both are physiologically present in the body B. They act on physiological receptors C. Both affect many physiological processes D. They have opposite physiological effects

Description : The antagonism between adrenaline and histamine is called ‘physiological antagonism’ because: A. Both are physiologically present in the body B. They act on physiological receptors C. Both affect many physiological processes D. They have opposite physiological effects

Last Answer : D. They have opposite physiological effects

The antagonism between adrenaline and histamine is called ‘physiological antagonism’ because: A. Both are physiologically present in the body B. They act on physiological receptors C. Both affect many physiological processes D. They have opposite physiological effects

Description : The antagonism between adrenaline and histamine is called ‘physiological antagonism’ because: A. Both are physiologically present in the body B. They act on physiological receptors C. Both affect many physiological processes D. They have opposite physiological effects

Last Answer : D. They have opposite physiological effects

A drug which does not produce any action by itself but decreases the slope of the log dose-response curve and suppresses the maximal response to another drug is a: A. Physiological antagonist B. Competitive antagonist C. Noncompetitive antagonist D. Partial agonist

Description : A drug which does not produce any action by itself but decreases the slope of the log dose-response curve and suppresses the maximal response to another drug is a: A. Physiological antagonist B. Competitive antagonist C. Noncompetitive antagonist D. Partial agonist

Last Answer : C. Noncompetitive antagonist

Study of drug-receptor interaction has now shown that: A. Maximal response occurs only when all receptors are occupied by the drug B. Drugs exert an ‘all or none’ action on a receptor C. Receptor and drugs acting on it have rigid complementary ‘lock and key’ structural features D. Properties of ‘affinity’ and ‘intrinsic activity’ are independently variable

Description : Study of drug-receptor interaction has now shown that: A. Maximal response occurs only when all receptors are occupied by the drug B. Drugs exert an all or none' action on a ... lock and key' structural features D. Properties of affinity' and intrinsic activity' are independently variable

Last Answer : D. Properties of ‘affinity’ and ‘intrinsic activity’ are independently variable

A drug which does not produce any action by itself but decreases the slope of the log dose-response curve and suppresses the maximal response to another drug is a: A. Physiological antagonist B. Competitive antagonist C. Noncompetitive antagonist D. Partial agonist

Description : A drug which does not produce any action by itself but decreases the slope of the log dose-response curve and suppresses the maximal response to another drug is a: A. Physiological antagonist B. Competitive antagonist C. Noncompetitive antagonist D. Partial agonist

Last Answer : C. Noncompetitive antagonist

When therapeutic effects decline both below and above a narrow range of doses, a drug is said to exhibit: A. Ceiling effect B. Desensitization C. Therapeutic window phenomenon D. Nonreceptor mediated action

Description : When therapeutic effects decline both below and above a narrow range of doses, a drug is said to exhibit: A. Ceiling effect B. Desensitization C. Therapeutic window phenomenon D. Nonreceptor mediated action

Last Answer : C. Therapeutic window phenomenon

Study of drug-receptor interaction has now shown that: A. Maximal response occurs only when all receptors are occupied by the drug B. Drugs exert an ‘all or none’ action on a receptor C. Receptor and drugs acting on it have rigid complementary ‘lock and key’ structural features D. Properties of ‘affinity’ and ‘intrinsic activity’ are independently variable

Description : Study of drug-receptor interaction has now shown that: A. Maximal response occurs only when all receptors are occupied by the drug B. Drugs exert an all or none' action on a ... lock and key' structural features D. Properties of affinity' and intrinsic activity' are independently variable

Last Answer : D. Properties of ‘affinity’ and ‘intrinsic activity’ are independently variable

The pH of an amino acid depends (A) Optical rotation (B) Dissociation constant (C) Diffusion coefficient(D) Chain length

Description : The pH of an amino acid depends (A) Optical rotation (B) Dissociation constant (C) Diffusion coefficient(D) Chain length

Last Answer : Answer : B

Majority of drugs cross biological membranes primarily by: A. Passive diffusion B. Facilitated diffusion C. Active transport D. Pinocytosis

Description : Majority of drugs cross biological membranes primarily by: A. Passive diffusion B. Facilitated diffusion C. Active transport D. Pinocytosis

Last Answer : A. Passive diffusion

Majority of drugs cross biological membranes primarily by: A. Passive diffusion B. Facilitated diffusion C. Active transport D. Pinocytosis

Description : Majority of drugs cross biological membranes primarily by: A. Passive diffusion B. Facilitated diffusion C. Active transport D. Pinocytosis

Last Answer : C. Is affected by extent of ionization of drug molecules

The pharmacokinetics of drugs in the neonate differs from that in adults, because their: A. Intestinal transit is fast B. Drug metabolizing enzymes are overactive C. Tubular transport mechanisms are not well developed D. Glomerular filtration rate is high

Description : The pharmacokinetics of drugs in the neonate differs from that in adults, because their: A. Intestinal transit is fast B. Drug metabolizing enzymes are overactive C. Tubular transport mechanisms are not well developed D. Glomerular filtration rate is high

Last Answer : C. Tubular transport mechanisms are not well developed

The pharmacokinetics of drugs in the neonate differs from that in adults, because their: A. Intestinal transit is fast B. Drug metabolizing enzymes are overactive C. Tubular transport mechanisms are not well developed D. Glomerular filtration rate is high

Description : The pharmacokinetics of drugs in the neonate differs from that in adults, because their: A. Intestinal transit is fast B. Drug metabolizing enzymes are overactive C. Tubular transport mechanisms are not well developed D. Glomerular filtration rate is high

Last Answer : C. Tubular transport mechanisms are not well developed

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

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

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

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

If the effect of combination of two drugs is equal to the sum of their individual effects, the two drugs are exhibiting: A. Potentiation B. Synergism C. Cross tolerance D. Antagonism

Description : If the effect of combination of two drugs is equal to the sum of their individual effects, the two drugs are exhibiting: A. Potentiation B. Synergism C. Cross tolerance D. Antagonism

Last Answer : B. Synergism

Fixed dose combination formulations are not necessarily appropriate for: A. Drugs administered in standard doses B. Drugs acting by the same mechanism C. Antitubercular drugs D. Antihypertensive drugs

Description : Fixed dose combination formulations are not necessarily appropriate for: A. Drugs administered in standard doses B. Drugs acting by the same mechanism C. Antitubercular drugs D. Antihypertensive drugs

Last Answer : B. Drugs acting by the same mechanism

If the effect of combination of two drugs is equal to the sum of their individual effects, the two drugs are exhibiting: A. Potentiation B. Synergism C. Cross tolerance D. Antagonism

Description : If the effect of combination of two drugs is equal to the sum of their individual effects, the two drugs are exhibiting: A. Potentiation B. Synergism C. Cross tolerance D. Antagonism

Last Answer : B. Synergism

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

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

The receptor transduction mechanism with the fastest time-course of response effectuation is: A. Adenylyl cyclase-cyclic AMP pathway B. Phospholipase C-IP3: DAG pathway C. Intrinsic ion channel operation D. Protein synthesis modulation

Description : The receptor transduction mechanism with the fastest time-course of response effectuation is: A. Adenylyl cyclase-cyclic AMP pathway B. Phospholipase C-IP3: DAG pathway C. Intrinsic ion channel operation D. Protein synthesis modulation

Last Answer : C. Intrinsic ion channel operation

The following is a competitive type of enzyme inhibitor: A. Acetazolamide B. Disulfiram C. Physostigmine D. Theophylline

Description : The following is a competitive type of enzyme inhibitor: A. Acetazolamide B. Disulfiram C. Physostigmine D. Theophylline

Last Answer : C. Physostigmine

Which of the following drugs acts by inhibiting an enzyme in the body: A. Atropine B. Allopurinol C. Levodopa D. Metoclopramide

Description : Which of the following drugs acts by inhibiting an enzyme in the body: A. Atropine B. Allopurinol C. Levodopa D. Metoclopramide

Last Answer : B. Allopurinol

Microsomal enzyme induction can be a cause of: A. Tolerance B. Physical dependence C. Psychological dependence D. Idiosyncrasy

Description : Microsomal enzyme induction can be a cause of: A. Tolerance B. Physical dependence C. Psychological dependence D. Idiosyncrasy

Last Answer : A. Tolerance

An undesirable effect of a drug that occurs at therapeutic doses and can be predicted from its pharmacological actions is called: A. Side effect B. Toxic effect C. Allergic reaction D. Idiosyncrasy

Description : An undesirable effect of a drug that occurs at therapeutic doses and can be predicted from its pharmacological actions is called: A. Side effect B. Toxic effect C. Allergic reaction D. Idiosyncrasy

Last Answer : A. Side effect

The therapeutic index of a drug is a measure of its: A. Safety B. Potency C. Efficacy D. Dose variability

Description : The therapeutic index of a drug is a measure of its: A. Safety B. Potency C. Efficacy D. Dose variability

Last Answer : A. Safety

The following statement is not true of ‘potency’ of a drug: A. Refers to the dose of the drug needed to produce a certain degree of response B. Can be related to that of its congeners by the relative position of its dose-response curve on the dose axis C. It is often not a major consideration in the choice of a drug D. It reflects the capacity of the drug to produce a drastic response

Description : The following statement is not true of potency' of a drug: A. Refers to the dose of the drug needed to produce a certain degree of response B. Can be related to that of its congeners by ... consideration in the choice of a drug D. It reflects the capacity of the drug to produce a drastic response

Last Answer : D. It reflects the capacity of the drug to produce a drastic response

The loading dose of a drug is governed by its: A. Renal clearance B. Plasma half life C. Volume of distribution D. Elimination rate constant

Description : The loading dose of a drug is governed by its: A. Renal clearance B. Plasma half life C. Volume of distribution D. Elimination rate constant

Last Answer : C. Volume of distribution

Glomerular filtration of a drug is affected by its: A. Lipid solubility B. Plasma protein binding C. Degree of ionization D. Rate of tubular secretion

Description : Glomerular filtration of a drug is affected by its: A. Lipid solubility B. Plasma protein binding C. Degree of ionization D. Rate of tubular secretion

Last Answer : B. Plasma protein binding

The following attribute of a drug tends to reduce its volume of distribution: A. High lipid solubility B. Low ionisation at physiological pH values C. High plasma protein binding D. High tissue binding

Description : The following attribute of a drug tends to reduce its volume of distribution: A. High lipid solubility B. Low ionisation at physiological pH values C. High plasma protein binding D. High tissue binding

Last Answer : C. High plasma protein binding

If the total amount of a drug present in the body at a given moment is 2.0 g and its plasma concentration is 25 μg/ml, its volume of distribution is: A. 100 L B. 80 L C. 60 L D. 50 L

Description : If the total amount of a drug present in the body at a given moment is 2.0 g and its plasma concentration is 25 μg/ml, its volume of distribution is: A. 100 L B. 80 L C. 60 L D. 50 L

Last Answer : B. 80 L

The following attribute of a drug tends to reduce its volume of distribution: A. High lipid solubility B. Low ionisation at physiological pH values C. High plasma protein binding D. High tissue binding

Description : The following attribute of a drug tends to reduce its volume of distribution: A. High lipid solubility B. Low ionisation at physiological pH values C. High plasma protein binding D. High tissue binding

Last Answer : C. High plasma protein binding

2 If the total amount of a drug present in the body at a given moment is 2.0 g and its plasma concentration is 25 μg/ml, its volume of distribution is: A. 100 L B. 80 L C. 60 L D. 50 L

Description : 2 If the total amount of a drug present in the body at a given moment is 2.0 g and its plasma concentration is 25 μg/ml, its volume of distribution is: A. 100 L B. 80 L C. 60 L D. 50 L

Last Answer : B. 80 L

An immunologically mediated reaction to a drug producing stereotyped symptoms unrelated to its pharmacodynamic actions is: A. Hypersensitivity B. Supersensitivity C. Intolerance D. Idiosyncrasy

Description : An immunologically mediated reaction to a drug producing stereotyped symptoms unrelated to its pharmacodynamic actions is: A. Hypersensitivity B. Supersensitivity C. Intolerance D. Idiosyncrasy

Last Answer : A. Hypersensitivity