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

1 Answer

Answer :

A. Selective inhibition of high frequency neuronal discharges

Related questions

Description : The most probable mechanism of anticonvulsant action of phenytoin is: A. Facilitation of GABAergic inhibitory transmission B. Hyperpolarization of neurones C. Interaction with Ca2+ channels to promote Ca2+ influx D. Prolongation of voltage sensitive neuronal Na+ channel inactivation

Last Answer : D. Prolongation of voltage sensitive neuronal Na+ channel inactivation

Description : An epileptic woman controlled by phenytoin therapy conceives. Which of the following measures is most appropriate: A. Medical termination of pregnancy B. Withdraw phenytoin therapy C. ... lowest effective level D. Substitute phenytoin with a combination of carbamazepine and sodium valproate

Last Answer : C. Gradually reduce phenytoin dose to the lowest effective level

Description : Choose the drug that has been found to be more selective for the ω1 subtype of BZD receptor, and produces hypnotic action but little antianxiety, muscle relaxant or anticonvulsant actions: A. Zopiclone B. Zolpidem C. Flumazenil D. Melatonin

Last Answer : B. Zolpidem

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 : The positive inotropic action of digoxin takes several hours to develop because: A. Binding of digoxin to Na+K+ATPase is slow B. After Na+K+ATPase inhibition by digoxin, Ca2+ loading of myocardial ... +ATPase through modification of gene function which takes time D. Both A' and B' are correc

Last Answer : D. Both ‘A’ and ‘B’ are correct

Description : Methylxanthines exert the following action(s) at cellular/molecular level: A. Intracellular release of Ca2+ B. Antagonism of adenosine C. Inhibition of phosphodiesterase D. All of the above

Last Answer : D. All of the above

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 : hat is/are the consequence(s) of myocardial Na+ K+ ATPase inhibition by digoxin: A. Increased intracellular Na+ ion concentration B. Increased cytosolic Ca2+ ion concentration C. Increased intracellular K+ ion concentration D. Both ‘A’ and ‘B’ are correct

Last Answer : D. Both ‘A’ and ‘B’ are correct

Description : Which one of the followings is used as a mood stabilizer for bipolar disorder and also in certain epileptic convulsions? (A) Phenytoin (B) Lithium (C) Sodium valproate (D) Fluoxetine

Last Answer : (C) Sodium valproate

Description : Sodium valproate has been shown to: A. Prolong neuronal Na+ channel inactivation B. Attenuate ‘T’ type Ca2+ current in neurones C. Inhibit degradation of GABA by GABA-transaminase D. All of the above

Last Answer : D. All of the above

Description : The primary action by which entacapone and tolcapone enhance the therapeutic effect of levodopa-carbidopa in parkinsonism is: A. Inhibition of levodopa methylation in the liver B. Inhibition of ... of dopamine in the brain D. Facilitation of active transport of levodopa across brain capillaries

Last Answer : A. Inhibition of levodopa methylation in the liver

Description : Despite having anticonvulsant action, diazepam is not used in the treatment of epilepsy because: A. It is not effective orally B. It causes sedation C. Its anticonvulsant action wanes off with chronic use D. Both ‘B’ and ‘C’ are correct

Last Answer : D. Both ‘B’ and ‘C’ are correct

Description : The following statement(s) is/are correct in relation to diazepam and chlorpromazine: A. Both have anticonvulsant property B. Both do not carry abuse liability C. Both have antianxiety action D. All of the above are correc

Last Answer : C. Both have antianxiety action

Description : Select the correct statement about benzodiazepines (BZDs): A. All BZDs facilitate GABA mediated Cl¯ influx into neurones B. Different BZDs exert the same degrees of hypnotic, anxiolytic and anticonvulsant ... at all neuronal sites D. The muscle relaxant action of BZDs is not blocked by flumazenil

Last Answer : A. All BZDs facilitate GABA mediated Cl¯ influx into neurones

Description : The following is true about actions of ethylalcohol: A. It exerts anticonvulsant action followed by lowering of seizure threshold B. It lowers pain threshold C. It increases confidence and reduces number of errors D. It increases heat production and helps to keep warm in cold weather

Last Answer : A. It exerts anticonvulsant action followed by lowering of seizure threshold

Description : Methylxanthines exert the following action (s) at cellular/molecular level (a) Intracellular release of Ca2+ (b) Antagonism of adenosine (c) Inhibition of phosphodiesterase (d) All of the above

Last Answer : Ans: D

Description : Selective inhibition of conditioned avoidance response in animals by a drug indicates that the drug is likely to be effective in: A. Anxiety B. Major depression C. Schizophrenia D. Manic-depressive illness

Last Answer : C. Schizophrenia

Description : Selective inhibition of thromboxane A2 synthesis by low dose aspirin therapy might retard the progression of: A. Pregnancy induced hypertension B. Steroid induced hypertension C. Renal hypertension D. Malignant hypertension

Last Answer : A. Pregnancy induced hypertension

Description : Mini-dose heparin has been shown to be useful in the prophylaxis of postoperative venous thrombosis. Mechanism(s) by which low-dose heparin is/are thought to protect against venous ... aggregation and subsequent platelet release action d. A mild prolongation of activated partial thromboplastin time

Last Answer : Answer: a, b, c Low-dose heparin is thought to protect against venous thrombosis through three different mechanisms. First, antithrombin III activity with its inhibition of activated Factor X is ... release reaction. The standard doses of heparin administered (5000 units bid) does not affect aPTT

Description : The therapeutic effect of sulfasalazine in ulcerative colitis is exerted by: A. Inhibitory action of the unabsorbed drug on the abnormal colonic flora B. Breakdown of the drug in ... locally C. Release of sulfapyridine having antibacterial property D. Systemic immunomodulatory action of the drug

Last Answer : B. Breakdown of the drug in colon to release 5-aminosalicylic acid which suppresses inflammation locally

Description : Select the diuretic which is orally active, efficacious in acidosis as well as alkalosis, causes diuresis even in renal failure and has additional carbonic anhydrase inhibitory action: A. Mannitol B. Benzthiazide C. Indapamide D. Furosemide

Last Answer : D. Furosemide

Description : The following effect(s) of tamoxifen citrate indicate(s) that it possesses tissue specific estrogenic action as well: A. Inhibition of breast cancer cells B. Endometrial proliferation C. Hot flushes in premenopausal women D. All of the above

Last Answer : B. Endometrial proliferation

Description : The most important mechanism of antiinflammatory action of glucocorticoids is: A. Inhibition of lysosomal enzymes B. Restriction of recruitment of inflammatory cells at the site of inflammation C. Antagonism of action of interleukins D. Suppression of complement function

Last Answer : B. Restriction of recruitment of inflammatory cells at the site of inflammation

Description : Action of Insulin does not include the following: A. Facilitation of glucose transport into cells B. Facilitation of glycogen synthesis by liver C. Facilitation of neoglucogenesis by liver D. Inhibition of lipolysis in adipose tissue

Last Answer : . Facilitation of neoglucogenesis by liver

Description : The following drug can cause rickets in children by interfering with vitamin D action: A. Tetracycline B. Digoxin C. Phenytoin D. Ciprofloxacin

Last Answer : C. Phenytoin

Description : The most important mechanism by which tetracycline antibiotics exert antimicrobial action is: A. They chelate Ca2+ ions and alter permeability of bacterial cell membrane B. They bind to 30S ribosomes ... peptide chain in the bacteria D. They interfere with DNA mediated RNA synthesis in bacteria

Last Answer : B. They bind to 30S ribosomes and inhibit bacterial protein synthesis

Description : Dantrolene sodium reduces skeletal muscle tone by: A. Reducing acetylcholine release from motor nerve endings B. Suppressing spinal polysynaptic reflexes C. Inhibiting the generation of muscle action potential D. Reducing Ca2+ release from sarcoplasmic reticulum in the muscle fibre

Last Answer : D. Reducing Ca2+ release from sarcoplasmic reticulum in the muscle fibre

Description : The electrophysiological effects of digitalis on Purkinje fibres include the following except: A. Enhancement of resting membrane potential B. Decrease in the slope of phase-0 depolarization C. Increase in the rate of phase-4 depolarization D. Abbreviation of action potential duration

Last Answer : A. Enhancement of resting membrane potential

Description : Folinic acid is specifically indicated for: A. Prophylaxis of neural tube defect in the offspring of women receiving anticonvulsant medication B. Counteracting toxicity of high dose methotrexate C. Pernicious anaemia D. Anaemia associated with renal failure

Last Answer : C. Pernicious anaemia

Description : Of the following neurotransmitters, which demonstrates inhibitory action, helps control mood and sleep, and inhibits pain pathways? a) Serotonin The sources of serotonin are the brain ... d) Acetylcholine Acetylcholine is usually excitatory, but the parasympathetic effects are sometimes inhibitory.

Last Answer : a) Serotonin The sources of serotonin are the brain stem, hypothalamus, and dorsal horn of the spinal cord.

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 : 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 : The following statement is correct about buspirone: A. It interacts with benzodiazepine receptor as an inverse agonist B. It is a rapidly acting anxiolytic, good for panic states C. ... suppresses barbiturate withdrawal syndrome D. It has anxiolytic but no anticonvulsant or muscle relaxant propert

Last Answer : D. It has anxiolytic but no anticonvulsant or muscle relaxant property

Description : A 3-year-old boy gets seizures whenever he develops fever. Which is the most appropriate strategy so that he does not develop febrile convulsions: A. Treat fever with paracetamol and ... Continuous diazepam prophylaxis for 3 years D. Intermittent diazepam prophylaxis started at the onset of fever

Last Answer : D. Intermittent diazepam prophylaxis started at the onset of fever

Description : Select the anticonvulsant drug that acts as a GABAtransaminase inhibitor: A. Gabapentin B. Vigabatrin C. Lamotrig

Last Answer : B. Vigabatrin

Description : The barbiturate having higher anticonvulsant: sedative activity ratio is: A. Pentobarbitone B. Phenobarbitone C. Butabarbitone D. Thiopentone

Last Answer : B. Phenobarbitone

Description : Barbiturates exert the following actions except: A. Anticonvulsant B. Analgesic C. Antianxiety D. Respiratory depressant

Last Answer : B. Analgesic

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 : The following adverse effect(s) of phenytoin is/are related to high plasma drug concentration: A. Ataxia B. Hirsutism C. Gum hyperplasia D. All of the above

Last Answer : A. Ataxia

Description : The characteristic feature of phenytoin pharmacokinetics is: A. High first pass metabolism B. Nonsaturation kinetics of metabolism C. Capacity limited metabolism saturating at higher therapeutic concentration range D. Extrahepatic metabolism

Last Answer : C. Capacity limited metabolism saturating at higher therapeutic concentration range

Description : The following action(s) of heparin is/are essential for inhibition of factor Xa: A. Facilitation of antithrombin III mediated inhibition of factor XIIa B. Provision of scaffold for the clotting factor ... configurational change in antithrombin III to expose its interacting sites D. Both A' and B

Last Answer : C. Induction of a configurational change in antithrombin III to expose its interacting sites

Description : Shortacting nifedipine formulation is not recommended now for treatment of hypertension because: A. It tends to increase heart rate and cardiac work B. It invokes pronounced reflex sympathetic discharges C. It can impair haemodynamics in patients with diastolic dysfunction D. All of the above

Last Answer : D. All of the above

Description : The most probable mechanism of action of mebendazole is: A. Depolarization of membrane and spastic paralysis of the worm B. Hyperpolarization of membrane and flaccid paralysis of the worm C. Loss of ... inhibition of glucose uptake in the worm D. Tegument damage and leakage of contents of the worm

Last Answer : C. Loss of intracellular microtubules and inhibition of glucose uptake in the worm

Description : The antiviral action of amantadine is exerted through: A. Interaction with the viral M2 protein B. Interaction with a virus directed thymidine kinase C. Inhibition of a viral protease enzyme D. Inhibition of viral RNA mediated DNA synthesi

Last Answer : A. Interaction with the viral M2 protein

Description : Bactericidal action of aminoglycoside antibiotics is due to: A. Inhibition of bacterial protein synthesis B. Alteration of bacterial cell membrane permeability C. Damage to bacterial cell wall D. Inhibition of bacterial oxidative metabolism

Last Answer : B. Alteration of bacterial cell membrane permeability

Description : What is true of nimesulide: A. It exerts antiinflammatory action by several mechanisms in addition to cyclooxygenase inhibition B. It is preferred for long-term use in rheumatoid arthritis C. It is contraindicated in aspirin intolerant asthma patients D. All of the above

Last Answer : A. It exerts antiinflammatory action by several mechanisms in addition to cyclooxygenase inhibition

Description : Which histamine H2 blocker has most marked inhibitory effect on microsomal cytochrome P-450 enzyme: A. Cimetidine B. Ranitidine C. Roxatidine D. Famotidine

Last Answer : A. Cimetidine

Description : Strychnine produces convulsions by: A. Stimulating NMDA receptors B. Facilitating the excitatory transmitter glutamate C. Blocking the inhibitory transmitter GABA D. Blocking the inhibitory transmitter glycine

Last Answer : D. Blocking the inhibitory transmitter glycine

Description : The following hypothalamic regulatory hormone is not a peptide: A. Growth hormone release inhibitory hormone B. Prolactin release inhibitory hormone C. Gonadotropin releasing hormone D. Corticotropin releasing hormone (

Last Answer : B. Prolactin release inhibitory hormone

Description : ndapamide differs from other diuretics in that: A. It has selective antihypertensive action at doses which cause little diuresis B. It is a more efficacious antihypertensive C. Its antihypertensive action develops more rapidly D. All of the above

Last Answer : A. It has selective antihypertensive action at doses which cause little diuresis