Pharmacology | Set 1

1. Regarding paraquat poisoning

A. The interval between ingestion and death is usually hours because of immediate pulmonary toxicity

B. Mechanism of action involves single electron oxidation of the herbicide to free radical species

C. Probable human lethal dosage is 50-500mg/kg

D. Oxygen high flow stops the pulmonary lesions occurring

E. Paraquat doesn’t affect hepatic or renal functions

Correct : C. Probable human lethal dosage is 50-500mg/kg

2. Regarding NSAIDs

A. Piroxicam has a half life of >50 hours

B. Aspirin reversibly inhibits COX

C. Diclofenac is a selective COX1 inhibitor

D. Indomethacin is relatively free of adverse side effects

E. Ibuprofen is predominantly excreted unchanged in the urine

Correct : A. Piroxicam has a half life of >50 hours

3. Regarding paracetamol (acetaminophen)

A. Less than 5% is excreted unchanged

B. Acetaminophen has no anti-inflammatory properties

C. The half life of paracetamol is 2-3 hours

D. Haemolytic anaemia has rarely been noted with paracetamol

E. All of the above are true

Correct : E. All of the above are true

4. Regarding lead toxicity

A. Lead can induce an anaemia that is macrocytic

B. Young children absorb about 10% of ingested inorganic lead

C. Lead induced peripheral neuropathy often involves upper limb extensors resulting in wrist drop

D. High dose organic lead poisoning usually results in severe pneumonitis

E. All patients with elevated blood lead levels should have chelation treatment whether symptomatic or not

Correct : C. Lead induced peripheral neuropathy often involves upper limb extensors resulting in wrist drop

5. Regarding agents used to treat gout

A. As little as 8mg of colchicine taken over 24 hours may be fatal

B. Allopurinol is a xanthine oxidase stimulator

C. Probenecid is an organic alkaline substance

D. Colchicine may precipitate acute attacks of gout

E. Aspirin is effective against gout as it inhibits urate crystal phagocytosis

Correct : A. As little as 8mg of colchicine taken over 24 hours may be fatal

6. All of the following may be seen in organophosphate poisoning EXCEPT

7. Regarding aspirin

A. The average anti-inflammatory dose of aspirin is 0.6g up to 4 hourly

B. Aspirin’s main side effect at usual doses is rash

C. Aspirin’s antiplatelet effect lasts 8 – 10 days

D. At low toxic doses – respiratory acidosis may occur

E. Aspirin has a pka of 4.5

Correct : C. Aspirin’s antiplatelet effect lasts 8 – 10 days

8. The main mechanism of action of colchicine is

A. Inhibition of polymorphonuclear leucocytes

B. Inhibition of synoviocyte phagocytosis

C. Reduced formation of leukotriene D4

D. Inhibition of mononuclear phagocytes

E. Decreasing the body pool of urate

Correct : A. Inhibition of polymorphonuclear leucocytes

9. Aspirin inhibits all of the following EXCEPT

10. Acetaminophen (paracetamol) can undergo all of the following biotransformation reactions EXCEPT

11. Aspirin

A. Is hydrolysed to acetone and salicylate

B. Exhibits first order kinetics with elimination in low doses

C. Is mostly conjugated by the liver and excreted in the bile

D. Reversibly blocks the cyclooxygenase enzyme

E. Causes an immediate doubling of bleeding time

Correct : B. Exhibits first order kinetics with elimination in low doses

12. Regarding NSAIDs

A. At high doses diclofenac demonstrates zero order kinetics

B. Aspirin is a reversible inhibitor of cyclooxygenase

C. Aspirin at doses of <2g/day reduces uric acid levels

D. All NSAIDs can be found in synovial fluid after repeated dosing

E. Use of ibuprofen and aspirin together increases the anti inflammatory effect

Correct : D. All NSAIDs can be found in synovial fluid after repeated dosing

13. The metabolic pathway of detoxification that becomes increasingly important in paracetamol toxicity is

A. Conjugation with glucuronide

B. Oxidation

C. Reduction

D. Cytochrome p-450 dependent glutathione conjugation

E. Methylation

Correct : D. Cytochrome p-450 dependent glutathione conjugation

15. Which of the following symptoms of aspirin toxicity occurs at plasma salicylate concentrations of 100mg/dl?

16. All of the following drugs can cause a wide anion gap metabolic acidosis EXCEPT

17. Which of the following drug overdoses may be amenable to the elimination technique of haemodialysis

18. Which of the following antidote – drug pairings is INCORRECT

A. Acetaminophen → n-acetyl cysteine

B. β blockers → glucagon

C. Opioids → naloxone

D. Benzodiazepines → Flumazenil

E. Tricyclic antidepressants → physostigmine

Correct : E. Tricyclic antidepressants → physostigmine

19. Regarding carbon monoxide poisoning

A. CO has an affinity for Hb that is about 2000 times that of oxygen

B. Hyperbaric oxygen is indicated as a treatment for all patients with CO Hb levels >20%

C. The average concentration of CO in the atmosphere is about 0.1ppm

D. With room air at 1atm the elimination half time of CO is about 80 minutes

E. The foetus is resistant to the effects of CO exposure

Correct : C. The average concentration of CO in the atmosphere is about 0.1ppm

22. Drugs which enhance other drug metabolism include all of the following EXCEPT

24. Heparin and protamine used together is an example of

25. The half life of a drug with a Vd of 200ml/70kg and clearance of 10ℓ/hr/70kg is

26. All of the following are true regarding penicillins EXCEPT

A. Most penicillins only cross the blood brain barrier when the meninges are inflamed.

B. Penicillins don’t require dosage adjustment in renal failure

C. Penicillins inhibit cross linkage of peptidoglycans in the cell wall

D. Piperacillin is a penicillin active against pseudomonas

E. Only about 5 to 10% of people with a past history of penicillin allergy have a reaction on re exposure

Correct : B. Penicillins don’t require dosage adjustment in renal failure

27. Ciprofloxacin

A. Is a defluorinated analogue of nalidixic acid

B. Inhibits tropoisomerases 2 and 3

C. Has no gram positive cover

D. Has a bioavailability of 30%

E. May cause an arthropathy

Correct : E. May cause an arthropathy

28. Resistance to B lactams

A. Can be due to an efflux pump

B. Is most commonly due to modification of the target PBPs

C. Does not involve penetration of drug to target PBPs

D. Infers resistance only to penicillinc

E. Can involve up to 5 different B lactamases

Correct : A. Can be due to an efflux pump

29. Macrolides

A. Have enhanced activity at acidic pH

B. Have little activity against legionella

C. Have half lives which increase in patients with anuria

D. Induce cytochrome p450 enzymes

E. Are contraindicated in neonates

Correct : C. Have half lives which increase in patients with anuria

30. Flucloxacillin

A. Is ineffective against streptococci

B. Is active against enterococci and anaerobes

C. Blocks transpeptidation and inhibits peptidoglycan synthesis

D. Is poorly absorbed orally

E. Has excellent penetration into CNS and prostate

Correct : C. Blocks transpeptidation and inhibits peptidoglycan synthesis

31. All of the following inhibit nucleic acid synthesis EXCEPT

32. Which of the following is a second generation cephalosporin?

33. Regarding the pharmacokinetics of the tetracyclines

A. Tetracyclines are 40 to 80 % bound by serum proteins

B. Absorption is enhanced by coadministration of antacids

C. Tetracyclines cross the blood brain barrier easily

D. Doxycycline is excreted predominantly by the kidney

E. Demeclocyline is a short acting tetracycline drug

Correct : A. Tetracyclines are 40 to 80 % bound by serum proteins

34. All of the following are recognized adverse effects of isoniazid EXCEPT

A. Hepatitis

B. Peripheral neuropathy

C. Retrobulbar neuritis

D. Decreased phenytoin metabolism – increased phenytoin blood levels / toxicity

E. CNS toxicity

Correct : C. Retrobulbar neuritis

35. Vancomycin

A. 90% of vancomycin is excreted by glomerular filtration

B. Inhibits proteinsynthesis in bacteria

C. Is bactericidal against gram negative bacilli

D. Is well absorbed from the GIT

E. One adverse reaction to infusions of vancomycin is the “blue man” syndrome

Correct : A. 90% of vancomycin is excreted by glomerular filtration

36. Regarding mechanisms of antiviral drug action

A. blockage of viral uncoating is caused by rifampicin

B. Zidovudine is a protease inhibitor

C. Amantidine blocks viral DNA packaging and assembly

D. Indinavir is a reverse transcriptase inhibitor

E. Acyclovir inhibits viral DNA synthesis

Correct : E. Acyclovir inhibits viral DNA synthesis

37. Regarding toxicity of antibiotics

A. Enamel dysplasia is common with aminoglycosides

B. Gray baby syndrome occurs with rifampicin use

C. Haemolytic anaemias can occur with sulphonamide use

D. Nephritis is the most common adverse reaction with isoniazid

E. Disulfiram like reaction can occur with macrolides

Correct : C. Haemolytic anaemias can occur with sulphonamide use

38. Chloramphenicol

A. Does not penetrate the blood brain barrier

B. Must be administered parenterally

C. Can be safely used in premature infants

D. Can cause depression of bone marrow function

E. Can cause discoloration of developing teeth when given to children

Correct : D. Can cause depression of bone marrow function

39. Spironolactone

A. Has a steroid structure

B. Is a partial agonist

C. Promotes sodium retention

D. Increases potassium loss

E. Is a loop diuretic

Correct : A. Has a steroid structure

40. Which of the following drugs cause diuresis by the mechanisms indicated?

A. Ethanol – by preventing the reabsorption of sodium from renal tubular fluid

B. Digoxin – by inhibiting release of ADH

C. Dopamine – by inhibiting active transport of chloride over the entire length of the descending limb of the loop of Henle

D. Frusemide – by inhibiting carbonic anhydrase

E. Chlorothiazide – by inhibiting active sodium transport in the ascending limb of the loop of Henle

Correct : E. Chlorothiazide – by inhibiting active sodium transport in the ascending limb of the loop of Henle

41. All of the following antibiotics bind to the 50S subunit of the ribosome thereby inhibiting proteinsynthesis EXCEPT

42. Pharmacokinetics of doxycycline

A. 20% bound by serum proteins

B. 60-70% absorption after oral administration

C. Absorption is impaired by divalent cations, Al3+, and antacids

D. Widely distributed especially into the CSF

E. Is eliminated via renal mechanisms

Correct : C. Absorption is impaired by divalent cations, Al3+, and antacids

44. Resistance to Penicillin and other β lactams is due to

A. Modification of target PBPs

B. Impaired penetration of drug to target PBPs

C. Presence of an efflux pump

D. Inactivation of antibiotics by β lactamase

E. All of the above

Correct : E. All of the above

45. All of the following are recognised adverse effects of isoniazid EXCEPT

A. Hepatitis

B. Peripheral neuropathy

C. Retrobulbar neuritis

D. ↓ Phenytoin metabolism → ↑ Phenytoin blood levels and toxicity

E. CNS toxicity

Correct : C. Retrobulbar neuritis

46. Regarding fluoroquinolones

A. Ciprofloxacin is ineffective in the treatment of gonococcus

B. Norfloxacin and Ciprofloxacin are predominantly faecally excreted

C. Norfloxacin and Ciprofloxacin have long half lives (12 hours)

D. They have poor oral bioavailability

E. May damage growing cartilage in children less than 18 years of age

Correct : E. May damage growing cartilage in children less than 18 years of age

47. Vancomycin

A. Is never orally administered as it is poorly absorbed from the GIT

B. Binds to the 30S unit on the ribosome and inhibits protein synthesis

C. 60% of vancomycin is excreted by glomerular filtration

D. Parenteral vancomycin is commonly used for treatment of infections caused by methicillin susceptible staphylococci

E. Adverse reactions to vancomycin are encountered in about 10% of patients

Correct : E. Adverse reactions to vancomycin are encountered in about 10% of patients

48. Regarding the “azole” group of antifungals

A. Fluconazole has low water solubility

B. Ketoconazole may be given IV/PO

C. Itraconazole undergoes renal elimination

D. Clotrimazole is the treatment of choice for systemic candidiasis – given orally

E. They work by reduction of ergosterol synthesis by inhibition of fungal cytochrome P450 enzymes

Correct : E. They work by reduction of ergosterol synthesis by inhibition of fungal cytochrome P450 enzymes

49. The fluoroquinolones

A. May be administered to patients with severe campylobacter infection

B. Work by inhibiting dihydrofolate reductase

C. Have little effect against gram positive organisms

D. Are heavily metabolised in the liver

E. Are safe to give to breast feeding mothers

Correct : A. May be administered to patients with severe campylobacter infection

50. Clindamycin

A. Inhibits bacterial cell wall synthesis

B. Is often used for prophylaxis of endocarditis in patients with Valvular disease who are undergoing dental procedures

C. Penetrates through BBB into CSF well

D. Works well against enterococci and gram negative aerobic organisms

E. Is 10% protein bound

Correct : B. Is often used for prophylaxis of endocarditis in patients with Valvular disease who are undergoing dental procedures

51. Which of the following is a second generation cephalosporin?

52. The cephalosporin with the highest activity against gram positive cocci is

53. Regarding the penicillins

A. Penicillin ix excreted into breast milk to levels 3-15% of those present in the serum

B. Absorption of amoxyl is impaired by food

C. Benzathine penicillin is given PO

D. Penicillins are 90% excreted by glomerular filtration

E. Dosage of nafcillin should be adjusted in the presence of renal failure

Correct : A. Penicillin ix excreted into breast milk to levels 3-15% of those present in the serum

54. Rifampicin

A. Inhibits hepatic microsomal enzymes

B. Inhibits DNA synthesis

C. Is bactericidal for mycobacteria

D. Is not appreciably protein bound

E. Is predominantly excreted unchanged in the urine

Correct : C. Is bactericidal for mycobacteria

55. Regarding resistance to antibiotics

A. Penicillinases cannot inactivate cephalosporins

B. Macrolides can be inactivated by transferases

C. Mutation of aminoglycoside binding site is its main mechanism of resistance

D. Tetracycline resistance is a marker for multidrug resistance

E. Resistance to antibiotics is rarely plasmid encoded

Correct : C. Mutation of aminoglycoside binding site is its main mechanism of resistance

56. Concerning toxicity of antibiotics

A. Enamel dysplasia is common with aminoglycosides

B. Grey Baby Syndrome occurs with rifampicin use

C. A disulfiram like reaction can occur with macrolides

D. Haemolytic anaemias can occur with sulphonamide use

E. Nephritis is the most common adverse reaction with isoniazid

Correct : D. Haemolytic anaemias can occur with sulphonamide use

57. Which of the following is considered to be bacteriostatic?

59. Regarding antiseptic agents – all of the following are true EXCEPT

A. Sodium hypochlorite is an effective antiseptic for intact skin

B. Potassium permanganase is an effective bactericidal agent

C. Formaldehyde may be used to disinfect instruments

D. Chlorhexidine is active against gram positive cocci

E. Ethanol is an effective skin antiseptic because it denatures microbial proteins

Correct : A. Sodium hypochlorite is an effective antiseptic for intact skin

60. Ciprofloxacin

A. Is a defluorinated analogue of nalidixic acid

B. Inhibits tropoisomerases 2 and 3

C. Has no gram positive cover

D. Has bioavailability of 30%

E. May cause an arthropathy

Correct : D. Has bioavailability of 30%

61. Aminoglycosides

A. Have a β lactam ring

B. Can produce neuromuscular blockade

C. Are DNA gyrase inhibitors

D. Normally reach high CSF concentrations

E. Have good oral absorption but high first pass metabolism

Correct : B. Can produce neuromuscular blockade

63. Regarding antivirals

A. Delvindine is a nucleoside reverse transcriptase inhibitor (NRTI)

B. Zidovudine (AZT) is a non nucleoside reverse transcriptase inhibitor (NNRTI)

C. NRTIs activate HIV-1 reverse transcriptase

D. Abacavir is a protease inhibitor

E. NRTIs require intracytoplasmic activation to the triphosphate form

Correct : E. NRTIs require intracytoplasmic activation to the triphosphate form

64. All of the following are true regarding metronidazole EXCEPT

A. It is used to treat giardia

B. It causes a metallic taste in the mouth

C. It inhibits alcohol dehydrogenase

D. It is used to treat gardnerella

E. It is useful against trichomonoas vaginalis

Correct : C. It inhibits alcohol dehydrogenase

65. Regarding antipsychotics as a group

A. Metabolites are important to the action of these drugs

B. Haloperidol has a higher systemic availability than thioridazine or chlorpromazine

C. Elimination half lives of these drugs range between 3 – 6 hours

D. This group of drugs generally has short clinical duration of action

E. Clozipine is a member of the dihydroindolone group

Correct : B. Haloperidol has a higher systemic availability than thioridazine or chlorpromazine

66. Which of the following antipsychotics (in excess dose) is responsible for cardiac arrhythmias?

67. Plasma lithium levels (assuming no change in daily lithium dose) may become toxic in the presence of all of the following EXCEPT

68. Regarding pharmacokinetics of antidepressants

A. Most are highly protein bound

B. Fluoxetine is poorly absorbed

C. Tricyclics are predominantly excreted unchanged in the urine

D. Plasma half lives of antidepressants are mostly less than 10 hours

E. The half life of the older MAOIs is helpful in governing doses

Correct : A. Most are highly protein bound

69. Which of the following drugs is potentially dangerous in a single drug overdose

70. Which of the following drugs is 99% protein bound in plasma

71. Which of the following drugs is contraindicated (absolutely) in a patient with porphyria

72. Regarding local anaesthetic agents

A. Lignocaine is also an antiarrhythmic of the Vaughan Williams classification group 1A

B. At normal pH the larger fraction of local anaesthetic in the body fluids will be in the unchanged form

C. Bupivacaine may cause an apparent cyanosis in some patients

D. The duration of action of procaine will be increased in the presence of liver disease

E. Local anaesthetic agents block conduction in small myelinated axons prior to blockade of other axons

Correct : E. Local anaesthetic agents block conduction in small myelinated axons prior to blockade of other axons

73. Regarding IV anaesthetic agents

A. Ketamine is the induction agent of choice in a head injured patient

B. Propofol has a slow offset of action

C. Etomidate causes hypotension more commonly than thiopentone

D. Ideal agents for neuroleptanalgesia are fentanyl and droperidol

E. Thiopentone is metabolised at a rate of 40-50% per hour in humans following a single dose

Correct : D. Ideal agents for neuroleptanalgesia are fentanyl and droperidol

74. Suxamethonium

A. Is a non-depolarising neuromuscular blocking agent

B. Is contraindicated in all eye operations

C. Stimulates cardiac muscarinic receptors and autonomic ganglia

D. Its action is directly terminated by the action of plasma cholinesterase

E. Should not be administered to patients with burns >24 hours old because of its hypercalcaemic effect

Correct : C. Stimulates cardiac muscarinic receptors and autonomic ganglia

75. Inhalational anaesthetics

A. Enflurane is proconvulsant

B. Isoflurane is the inhalational agent of choice in patients with active IHD

C. Nitrous oxide is a useful adjunct to volatile anaesthetic use in women in the first trimester of pregnancy

D. Halothane has a MAC value of 75% making it less potent than desflurane

E. Desflurane is extensively metabolised via the liver

Correct : A. Enflurane is proconvulsant

76. Phenytoin

A. Is 20-30% bound to albumin

B. Is the drug treatment of choice in absence seizures

C. Undergoes flow limited elimination

D. Steady state mean plasma concentrations varies disproportionately with the dose

E. Preferentially binds to activated state sodium channels

Correct : D. Steady state mean plasma concentrations varies disproportionately with the dose

77. Drugs of abuse can be extremely dangerous in the wrong hands! Which of the following is correct

A. Ketamine is structurally related to psilocybin

B. LSD acts on various 5 HT receptor subtypes to produce its mind altering effects

C. Marijuana causes mydriasis and conjunctival infection

D. Cocaine has a long plasma half life

E. Amphetamine like drugs cause marked stimulation of appetite

Correct : B. LSD acts on various 5 HT receptor subtypes to produce its mind altering effects

78. Flumazenil

A. Is cleared renally

B. Predictably reverses benzodiazepine induced respiratory depression

C. Antagonises CNS effects of opioids

D. Can precipitate seizures in mixed overdose

E. Has a half life of around 10 hours

Correct : D. Can precipitate seizures in mixed overdose

79. Regarding non-depolarising muscle relaxants

A. Pancuronium is eliminated via the kidney

B. Roacuronium is an isoquinolone derivative

C. Roacuronium undergoes Hoffman elimination

D. Vecuronium is eliminated predominantly via the kidney

E. Atracurium is eliminated via plasma pseudocholinesterase

Correct : A. Pancuronium is eliminated via the kidney

80. Which of the following is a direct serotonin agonist

81. The opiate associated with seizures when given in high doses to patients with renal failure is

82. Ethanol

A. Is lipid soluble

B. Is metabolised by the MEOS system at blood concentrations below 100mg/dl

C. Is a vasodilator

D. The most frequent neurological abnormality in chronic alcoholism is asymmetrical peripheral nerve injury specific to hands and feet

E. Alcohol is estimated to be responsible for approximately 10% of cases of hypertension

Correct : C. Is a vasodilator

84. Regarding temazepam – all of the following are true EXCEPT

A. It produces inactive metabolites

B. It induces enzymes only to a minimal extent

C. It causes less hangover than nitrazepam

D. It causes rebound insomnia

E. It increases REM sleep

Correct : E. It increases REM sleep

85. Regarding the antiepileptic drugs

A. Lorazepam has documented efficacy against absence seizures

B. Phenytoin is able to stimulate its own metabolism by enzyme induction

C. Valproate has a large Vd (>500l/70kg)

D. The most common dose related adverse effects of Carbamazepine are ataxia and diplopia

E. Vigabatrin works by sodium channel blockade

Correct : D. The most common dose related adverse effects of Carbamazepine are ataxia and diplopia

86. Benzodiazepines

A. Increase the duration of GABA gated chloride channel openings

B. Will depress (in high doses) the CNS to the point known as stage 3 of general anaesthesia

C. Bind to GABAβ receptors

D. Have extensive cardiodepressant effects in doses used to cause hypnosis

E. Decrease the duration of stage 2 NREM sleep

Correct : B. Will depress (in high doses) the CNS to the point known as stage 3 of general anaesthesia

87. Regarding drugs used in Parkinson’s disease

A. Bromocriptine is the first line drug to treat Parkinson’s disease in psychotic patients

B. 80-90% of a single dose of Levodopa enters the brain unaltered

C. Patients taking Selesiline to treat Parkinson’s disease are limited in what they can eat because of the tyranine reaction phenomenon

D. Amantadine has anti Parkinsonian effects and is administered at a dose of 100mg bd

E. Anti muscarinic drugs are of benefit in elimination of bradykinesia in Parkinson’s

Correct : D. Amantadine has anti Parkinsonian effects and is administered at a dose of 100mg bd

88. A patient complains of post op muscle pain. This is most likely to be due to

89. Lithium

A. Has rapid onset of action

B. Is partially renally excreted

C. Has no neurological side effects

D. Has no contraindications to be given in conjunction with NSAIDS

E. Is contraindicated in sick sinus syndrome

Correct : E. Is contraindicated in sick sinus syndrome

90. With respect to opioid receptors

A. Fentanyl works predominantly at the kappa receptors

B. Both U and delta receptors contribute to respiratory depression

C. Methadone is used for heroin withdrawal because its actions are predominantly at the delta receptors

D. Opioid receptors are coupled to a tyrosine kinase mechanism of action

E. Physical dependence and tolerance is caused by the rapid disintegration of receptors

Correct : B. Both U and delta receptors contribute to respiratory depression

91. Lignocaine

A. Penetrates the axon in its changed form

B. Is more potent than bupivacaine

C. Has higher affinity for activated than resting sodium channels

D. Is a weak acid

E. Blocks voltage gated sodium channels at their extracellular end

Correct : C. Has higher affinity for activated than resting sodium channels

92. Regarding adverse effects of propofol

A. Post op vomiting is common

B. Hypertension is a complication

C. Severe acidosis can occur with its use in paediatric respiratory infections

D. It is positively inotropic

E. Tremor is a common side effect

Correct : C. Severe acidosis can occur with its use in paediatric respiratory infections

93. Regarding inhaled anaesthetics

A. They reduce MAP in direct proportion to their alveolar concentration

B. Nitrous oxide has a relatively low MAC

C. Halogenated agents have a lower brain:blood partition coefficient

D. Nitrous oxide causes a decrease in tidal volume and an increase in respiratory rate

E. They decrease the metabolic rate in the brain by decreasing cerebral blood flow

Correct : A. They reduce MAP in direct proportion to their alveolar concentration

94. Local anaesthetic agents

A. Are primarily K+ channel blockers

B. Prevent repolarisation of the membrane

C. Can be used with a vasodilator to prolong local action

D. Activity is enhanced by high extracellular K+ concentration

E. Activity is enhanced by high extracellular Ca2+

Correct : D. Activity is enhanced by high extracellular K+ concentration

95. Which of the following side effects for given drugs is wrong

A. Phenytoin – gum hypertrophy

B. Ethosuximide – hirsuitism

C. Phenobarbital – enzyme induction

D. Carbamazepine – ataxia

E. Valproate – idiosyncratic hepatic toxicity

Correct : B. Ethosuximide – hirsuitism

97. Thiopentone

A. Is not lipid soluble

B. Can be used IM or IV to induce anaesthesia

C. Has good analgesic properties

D. Can cause convulsive movements

E. Anaesthetic action is terminated by redistribution from CNS to other highly vascularised tissues

Correct : E. Anaesthetic action is terminated by redistribution from CNS to other highly vascularised tissues

98. Nitrous oxide

A. Can be used with O2 as a carrier gas for halothane

B. Has poor analgesic properties

C. Forms a vapour which is explosive

D. Sensitises the heart to the action of catecholamines

E. Is an effective agent for inducing anaesthesia

Correct : A. Can be used with O2 as a carrier gas for halothane

99. Codeine

A. Is more potent than fentanyl

B. Frequently causes diarrhoea

C. Is used to treat nausea caused by morphine

D. Occurs in foxglove plants

E. Depresses the cough reflex

Correct : E. Depresses the cough reflex

100. Regarding GABA: all the following are true EXCEPT

A. Receptor blockers have anticonvulsant activity

B. Is found in high concentrations in the basal ganglia

C. Concentrations in the basal ganglia are abnormally low in Huntington’s chorea

D. Metabolism is inhibited by sodium valproate

E. Receptors are sensitive to the activity of benzodiazepines

Correct : A. Receptor blockers have anticonvulsant activity

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