6.1 The major post junctional cholinergic receptor is of the
muscarinic type at the following site:
A. Postganglionic parasympathetic
B. Adrenal medulla
C. Autonomic ganglia
D. Neuromuscular junction
6.2 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
6.3 The choline ester resistant to both true and pseudocholinesterase is:
A. Methacholine
B. Bethanechol
C. Benzoylcholine
D. Butyrylcholine
6.4 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
6.5 The cardiac muscarinic receptors:
A. Are of the M1 subtype
B. Are of the M2 subtype
C. Are selectively blocked by pirenzepine
D. Function through the PIP2 → IP3/DAG pathway
6.6 Cholinergic muscarinic receptor stimulation produces the following effects except:
A. Sweating
B. Rise in blood pressure
C. Bradycardia
D. Urination
6.7 The smooth muscle structure that is relaxed by cholinergic drugs is:
A. Colon
B. Gastric fundus
C. Major bronchi
D. Bladder trigone
6.8 Which of the following secretions is not stimulated by acetylcholine:
A. Tear
B. Bile
C. Pancreatic juice
D. Sweat
6.9 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
6.10 Pilocarpine is used for:
A. Glaucoma
B. Paralytic ileus
C. Urinary retention
D. All of the above
6.11 Actions of pilocarpine include the following except:
A. Sweating
B. Salivation
C. Miosis
D. Cycloplegia
6.12 The following inhibitor binds only to the ani-onic site of the cholinesterase enzyme:
A. Neostigmine
B. Physostigmine
C. Edrophonium
D. Dyflos
6.13 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
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 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
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
6.17 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
6.18 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 motornerve endings to a wider area activating neighbouring 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 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
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
6.26 Beta adrenergic blockers lower intraocular tension by:
A. Down regulating adenylyl cyclase in ciliary body through reduced activation of β2 adrenoceptors
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, watering from nose and eyes. His pulse is 120/min, low volume, BP 90/60 mm Hg, respiration shallow, pupil constricted, muscles flabby with occasional fasciculations. 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
6.40 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 A&B
D. Reversible anticholinesterases
6.1 A 6.2 B 6.3 B 6.4 C 6.5 B 6.6 B 6.7 D 6.8 B 6.9 D 6.10 A 6.11 D 6.12 C 6.13 B 6.14 A 6.15 B 6.16 B 6.17 C 6.18 D 6.19 B 6.20 A 6.21 A 6.22 B 6.23 D 6.24 D 6.25 C 6.26 A 6.27 D 6.28 A 6.29 A 6.30 D 6.31 C 6.32 B 6.33 D 6.34 A 6.35 A 6.36 C 6.37 D 6.38 C 6.39 A 6.40 C 6.41 B