MCQs PHARMACOLOGY: Autonomic nervous system

Acetylcholine has no therapeutic application because:

A. None of its actions are beneficial in any condition

B. Its effects are transient

C. It produces wide spread actions affecting many organs

D. Both ‘B’ and ‘C’ are correct


Pilocarpine is used for:

A. Glaucoma

B. Paralytic ileus

C. Urinary retention

D. All of the above

Actions of pilocarpine include the following except:
A. Sweating
B. Salivation
C. Miosis
D. Cycloplegia

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

13 Reactivation of cholinesterase enzyme occurs on hydrolysis of the inhibitor by the same enzyme mole-cule in case of the following anticholinesterase:
A. Edrophonium
B. Neostigmine
C. Dyflos
D. Tacrine

 

6.14 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
6.15 The organophosphates produce irreversible inhibition of cholinesterase because:
A. They bind to an allosteric site of the enzyme resulting in unfavourable conformation of este-ratic 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

6.16 Out of two anticholinesterases, drug ‘X’ is a tertiary amine while drug ‘Y’ is a quarternary ammonium com-pound. Then:
A. Drug ‘X’ is likely to be more potent than ‘Y’
B. Drug ‘X’ will be more suitable to be used as a miotic
C. Drug ‘Y’ will be completely metabolized in the body
D. Drug ‘Y’ will produce CNS effects

6.14 A
6.15 B
6.16 B

 

6.17 Neostigmine is preferred over physostigmine for treat-ing 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

6.18 The mechanism by which neostigmine improves con-traction of myasthenic muscle involves:
A. Repetitive binding of the acetylcholine mole-cules to the same receptors at the muscle end-plate
B. Diffusion of acetylcholine released from motor nerve endings to a wider area activating neigh-bouring receptors
C. Activation of motor end-plate receptors by neostigmine molecules themselves
D. All of the above

6.19 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

6.20 Edrophonium is more suitable for differentiating myas-thenic 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

6.17 C
6.18 D
6.19 B
6.20 A

 

6.21 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

6.22 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

6.23 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

6.24 Currently, the first choice drug for open angle glaucoma is:
A. Miotic eye drops
B. Ocular α2 adrenergic agonists
C. Ocular prostaglandin analogues
D. Ocular β adrenergic blockers

6.25 Timolol eye drops are preferred over pilocarpine eye drops by glaucoma patients because:
A. Timolol is more effective than pilocarpine
B. Timolol acts by enhancing uveo-scleral outflow
C. Timolol produces less ocular side effects
D. There are no contraindications to timolol

6.21 A
6.22 B
6.23 D
6.24 D
6.25 C

 

6.26 Beta adrenergic blockers lower intraocular tension by:
A. Down regulating adenylyl cyclase in ciliary body through reduced activation of β2 adreno-ceptors
B. Constricting ciliary blood vessels
C. Blocking adrenergic action on trabecular meshwork
D. Reducing aqueous formation unrelated to beta adrenoceptor mediation

6.27 Agonistic action on which of the following adrenergic receptors located on ciliary epithelial cells reduces aqueous secretion:
A. β1 receptor
B. β2 receptor
C. α1 receptor
D. α2 receptor

6.28 To be used as a topically applied ocular beta blocker a drug should have the following properties except:
A. Strong local anaesthetic activity
B. High lipophilicity
C. High ocular capture
D. Low systemic activity

6.29 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

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

 

6.31 The following is an α2 adrenergic agonist used as eyedrops to lower intraocular pressure:
A. Brinzolamide
B. Bambuterol
C. Brimonidine
D. Latanoprost

6.32 Which of the following is a prodrug of adrenaline used topically in glaucoma:
A. Brimonidine
B. Dipivefrine
C. Phenylpropanolamine
D. Dorzolamide

6.33 Apraclonidine is a clonidine congener which is used:
A. To suppress opioid withdrawal syndrome
B. To suppress menopausal syndrome
C. As Analgesic
D. To reduce intraocular tension

6.34 Dorzolamide is a:
A. Topically applied ocular carbonic anhydrase inhibitor
B. Second generation sulfonylurea hypoglycaemic
C. Topical sulfonamide antibacterial
D. Luminal amoebicide

6.35 Choose the correct statement about latanoprost:
A. It is a PGF2α derivative used in glaucoma
B. It is a selective α1 blocker used in benign hypertrophy of prostate
C. It is a 5-α-reductase inhibitor used to reduce the size of enlarged prostate gland
D. It is a PGE2 analogue used intravaginally for cervical priming

 

6.36 Select the diuretic that is most effective in acute congestive glaucoma:
A. Indapamide
B. Amiloride
C. Mannitol
D. Furosemide

6.37 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

6.38 A suspected case of poisoning has been brought to the casualty with weakness, fainting, involuntary passage of urine and stools, profuse sweating, salivation, water-ing from nose and eyes. His pulse is 120/min, low volume, BP 90/60 mm Hg, respiration shallow, pupil constricted, muscles flabby with occasional fascicu-lations. Which is the most likely type of poisoning:
A. Belladonna
B. Barbiturate
C. Anticholinesterase
D. Dicophane (DDT)

6.39 Which is the most important drug in the treatment of organophosphate poisoning:
A. Atropine sulfate
B. Pralidoxime
C. Diazepam
D. Adrenaline

6.36 C
6.37 D
6.38 C
6.39 A

 

6.40 Atropine does not antagonise the following feature of anticholinesterase poisoning:
A. Hypotension
B. Central excitation
C. Muscle paralysis
D. Bronchoconstriction

6.41 Pralidoxime can reactivate cholinesterase enzyme that has been inactivated by:
A. Carbamate anticholinesterases
B. Organophosphate anticholinesterases
C. Both carbamate and organophosphate anti-cholinesterases
D. Reversible anticholinesterases

7.1 Initial bradycardia caused by intramuscular injection of atropine is believed to be caused by:
A. Stimulation of medullary vagal centre
B. Stimulation of vagal ganglia
C. Blockade of M2 receptors on SA nodal cells
D. Blockade of muscarinic autoreceptors on vagal nerve endings

7.2 Atropine does not exert relaxant/antispasmodic effect on the following muscle:
A. Intestinal
B. Ureteric
C. Bronchial
D. Laryngeal

7.3 Atropine produces the following actions except:
A. Tachycardia
B. Mydriasis
C. Dryness of mouth
D. Urinary incontinence

 

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

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

7.6 The quarternary analogues of belladonna alkaloids are preferred over the natural alkaloids for antisecretory/ antispasmodic indications because:
A. They have additional nicotinic receptor block-ing activity
B. They are incompletely absorbed after oral administration
C. They are devoid of CNS and ocular effects
D. Dose to dose they are more potent than atropine

 

7.7 Inhaled ipratropium bromide has the following advan-tages except:
A. It does not alter respiratory secretions
B. It does not depress airway mucociliary clearance
C. It has faster onset of bronchodilator action than inhaled salbutamol
D. It only rarely produces systemic side effects


7.8 Which of the following anticholinergic drugs is primarily used in preanaesthetic medication and during surgery:
A. Glycopyrrolate
B. Pipenzolate methyl bromide
C. Isopropamide
D. Dicyclomine

7.9 Children are more susceptible than adults to the following action of atropine:
A. Tachycardia producing
B. Cycloplegic
C. Gastric antisecretory
D. Central excitant and hyperthermic

7.10 Glycopyrrolate is the preferred antimuscarinic drug for use before and during surgery because:
A. It is potent and fast acting
B. It has no central action
C. It has antisecretory and vagolytic actions
D. All of the above

7.11 Choose the relatively vasicoselective anticholinergic drug used for urinary frequency and urge incontinence due to detrusor instability:
A. Pirenzepine
B. Oxybutynin
C. Oxyphenonium
D. Glycopyrolate