3. Inhibitory[IPSP]Termination of Ach action hydrolysis by true cholinesterase Synthesis of ACH ATP + Acetate + CoEn-A Acetylcholine + CoEn-A = Acetyl CoEn-A + [acetyl transferase] Choline
4.
5. Signs and symptoms are due to excess of cholinergic activity resulting in excess of parasympathetic or sympathetic activity.
15. Q. Name two cholinesterases. Mention differences between them. 1 + 2 Ans. Two cholinesterases Acetyl cholinesterase[true] 2. Butyrylcholinesterase [pseudo] Differences
16. Write briefly on Edrophonium test. 3 [Tensilon]Edrophonium test To aid diagnosis i.v.2 mg of edrophonium chloride->45 seconds -> 8 mg if the first dose is without effect ->Brief improvement in strength ->MG diagnosis To moderate treatment in patient already being treated and c/o muscle weakness i.v. 2 mg. Decrease in strength indicates cholinergic crisis [Overdose of anticholinesterases in tt] Improvement signifies myasthenic crisis [Under dose of anticholinesterases in tt]
17. Q. Location of different subtypes of cholinoreceptors 2 Ans Location Receptor Gastric glands, Autonomic ganglia & CNS M1 SA node, AV node, Atrium, Ventricle, Auto receptors M2 Visceral smooth muscle, Iris, Ciliary muscle, Exocrine glands, Vascular endothelium. M3 CNS M4 M5 NM junction NM Autonomic ganglia, Adrenal medulla NN
18. Q. Why neostigmine is preferred over physostigmine in the treatment of myasthenia gravis? 2 Ans. Unlike physostigmine They have direct action on Nicotinic receptors at NM junction -Hence augmentation of action Being quaternary compounds do not cross BBB –No CNS effects
19. Q. Rationale for use of Timolol in glaucoma 3 Ans It is a non-slectiveβ blocker. It blocks the β2 receptors in ciliary body and reduces the secretion of aqueous humor. Produce smooth and sustained fall in IOT No change in pupil size as with pilocarpine. Convenience of dosage-once or twice daily Less adverse effects It has systemic ADEs like worsening of bronchial asthma, CHF and bradycardia
20. Q. Treatment of Atropine poisoning 2 Ans Gastric lavage with KMNO4-if ingested Nursed in a dark, quite room Cold sponging Physostigmine-1-3 mg i.v/s.c General supportive measures[ i.v. fluids, diazepam, respiration]
21. Q. Explain the actions of atropine on the eye and CNS. Explain the therapeutic uses of atropine substitutes 1+4 Ans Atropine on eye- It competitively blocks M3 receptors in constrictor pupillaeand ciliary muscle and effect passive mydriasis& Cycloplegia. It also increases IOT and abolishes light reflex. Atropine on CNS It crosses BBB. It is a CNS stimulant. Depresses vestibular system. Blocks cholinergic activity in basal ganglia and reduces tremor and rigidity in parkinsonism High doses produce delirium and hallucinations. ……..See next slide for uses of atropine substitutes
22. Q. Therapeutic uses of atropine substitutes Ans Motion sickness-Scopolamine Mydriatics-Homatropine, tropicamide, cyclopentolate Preanesthetic-Glycopyrrolate Intestinal and renal colic-Dicyclomine COPD, bronchial asthma-ipratropium & tiotropium bromide Parkinsonism-trihexyphenydyl Bradyarrhythmias-Atropine
23. Q. Write briefly on cycloplegicmydriatics -3 Ans. Cycloplegicmydriatics are the drugs which paralyze ciliary muscles and constrictor pupillae Antimuscarinics like atrpoine competitively block M3 receptors in these sites and effect Cycloplegia, passive mydriasis and abolish light reflex Eg. Atropine, homoatropine, tropicamide, cyclopentolate Atropine is the longest acting[7days] & tropicamide is the shortest. They are used for fundus examination, refractory testing , to give rest to muscles of eye and to break iris adhesions alternatively with miotics
24. Q. Mention two drugs used in myesthenia gravis. How will you differentiate myastenic crisis from choloinergic crisis 1+4 Ans Drugs in MG Anticholinesterases-Eg. Neostigmine, Pyridostigmine Glucocorticoids-Prednisolone Immunosuppresants-Azathioprine, Cyclosporine Cholinergic and myasthenic crisis Differentiated by Edrophonium test i.v.2 mg of edrophonium chloride-> Decrease in strength indicates cholinergic crisis [Overdose of anticholinesterases in tt] Improvement signifies myasthenic crisis [Under dose of anticholinesterases in tt]
25. Q. Mention any SIX drugs used in glaucoma. Explain the mechanism of action of any one drug 5 Drugs used in glaucoma Pilocarpine Timolol Latanaprost Acetazolamide Apraclonidine Mannitol MOA of α2 agonists α 2 agonists primarily reduce secretion of aqueous humor by acting on the α 2 receptors on the ciliary body. Subsidiary action is their α 1action, constriction of ciliary blood vessels,reduction in the synthesis of aqueous humor
26. Q. Uses and adverse effects of neuromuscular blockers 5 Uses Ans. Surgical relaxation[Adsjuant to GA] Tracheal Intubation Control of Ventilation-to reduce chest wall resistance in pts on ventilators Treatment of Convulsions in epilepsy SCH - brief procedures – endotracheal intubation, laryngoscopy, esophagoscopy, reduction of fractures and dislocations. With ECT-to prevent convulsions & trauma Adverse effects Muscle Pain-Myalgias are a common postoperative complaint [SCh] Respiratory paralysis Flushing Fall in BP[dtc] Precipitation of asthma[dtc] Malignant hyperthermia[SCh] Increased Intraocular Pressure[SCh] Increased Intragastric Pressure[SCh] Hyperkalemia [SCh+burns etc.]
27. Mention any SIX antimuscarinic agents Mention one use for each 5 Uses Antimuscarinics Atropine Scopolamine Homatropine Glycopyrrolate Benzhexol Ipratropium bromide OP poisoning Travel sickness Mydriatic for testing of errors of refraction Preanesthetic-antisecretory Parkinsonism As bronchodilator in COPD & Bronchial asthma
28. Q. List the differences between physostigmineand neostigmine- 2
29. Q. Explain the pharmacological basis for the following. 2 2. Pyridostigmine is used in myasthenia gravis 1. Atropine is contraindicated in patients with Glaucoma The intraocular tension tends to rise, especially in narrow angle glaucoma, as drainage of aqueous humor is compromised by crowding of the iris at angles Pyridostigmine is a reversible anti cholinesterase It inhibits the acetyl cholinesterase at neuromuscular junction and potentiates the action of Ach. More acetylcholine is made available to stimulate the less than normal no. of nicotinic receptors in myasthenia gravis. There by improves the muscle power, reduces fatigue. It requires less frequent dosing compared to neostigmine
30. Write briefly on ‘Succinylcholine’5 Chemistry: Resembles Ach, quaternary compound MOA: It is a depolarizing neuromuscular blocker. Produces Phase I block by persistent depolarization of nicotinic receptor and phase II block by receptor desensitization. Duration is about five mts. PK: Not absorbed orally nor crosses BBB. Hydrolyzed by pseudocholinesterase. Resistant to true cholinesterase. ADEs: In those with variant pseudocholinesterase can produce succinylcholineapnoea. Along with fluorinated anesthetics, in susceptible individuals can produce malignant hyperthermia. Hyperkalaemiain those with trauma and burns DIs: Should not be mixed with thiopentone in the same syringe Uses: 1. Short procedures like endoscopies, 2. Fracture reduction 3. Tracheal intubation
31. Q. Enumerate the types & subtypes of cholinergic receptors. Mention the sites where acetylcholine is theprincipal neurotransmitter. 2+2=4 Types & subtypes Muscarinic M1, M2, M3, M4, M5 Nicotinic NN, NM Cholinergic sites M1: Autonomic Ganglia, Gastric glands, CNS M2: SA node, AV node, atrium, ventricle, M3: Visceral smooth muscle Iris, ciliary muscles, exocrine glands, vascular endothelium M4, M5 : CNS NN :Autonomic ganglia & adrenal medulla NM :Neuromuscular junction
32. MCQ-1 Reactivation of cholinesterase enzyme inhibited by the following agent does not involve hydrolysis A. Edrophonium C. Physostigmine B. Galantamine D. Neostigmine
33. MCQ Anticholinergic which can be used to facilitate testing errors of refraction includes Dicyclomine Clidinium Oxybutynin Cyclopentolate
35. MCQ Non-selective betablockers used in the pharmacotherapy of glaucoma includes Betaxolol Atenolol Timolol Esmolol
36. MCQ Preferred anticholinesterase used in the treatment of Belladona[Atropine] poisoning is Physostigmine Edrophonium Neostigmine Parathion
37. MCQ Phenylephrine instilled in eye produces: Mydriasis but no cycloplegia. Cycloplegia but no mydriasis Both mydriasis and cycloplegia. Neither mydriasis nor cycloplegia.
38. MCQ Following are the drugs instilled locally into the eye in glaucoma EXCEPT Timolol Dorzolamide Acetazolamide Dipivefrine
39. MCQ Following drugs can be used in organophosphorous poisoning EXCEPT Prolidoxime Atropine Diazepam Acetylcholine
40. MCQ Which of the following skeletal muscle relaxant is shortest acting D-tubocuraine Pancuronium Cisatra curium Succinyl choline
41. The cholinomimetic drug which is not an alkaloid Acetylcholine Muscarine Pilocarpine Arecoline
42. The antimuscarinic agent which has high affinity for receptors in urinary bladder and salivary gland Oxybutynin Ipratropium Pirenzepine Tropicamide
44. Neostigmine can be used in all the following conditions, except: Cholinergic crisis Myasthenia gravis Paralytic ileus Curare poisoning
45. Pralidoxime is a Non-selective muscarinic receptor blocker Selective M1 receptor blocker Cholinesterase enzyme reactivator Cholinomimetic alkaloid
46. Following are the drugs effective in glaucoma, EXCEPT Dipivefrine Pilocarpine Timolol Dopamine
47. Ipratropium bromide inhalation is preferred over atropine as bronchodilator because Does not affect the mucociliary secretion Not absorbed when it is swallowed Lack of CNS effects All of the above
48. In which condition atropine is contraindicated? Heart block Peptic ulcer Hypertrophy of prostrate Bronchial asthma
49. Post operative muscle soreness may be a side effect of the following neuromuscular blocker d-Tubocurarine Succinylcholine Pancuronium -Atracurium
50. Which of the following drugs undergoes “Hoffmann” elimination. Succinylcholine Pancuronium Vecuronium -Atracurium
![[Cholinergic system] Model Questions and answers Dr.U.P.RathnakarMD.DIH.PGDHMwww.scribd.com](https://image.slidesharecdn.com/cholinergicsystemmodelquestionsanswers-111015120726-phpapp01/85/Cholinergic-system-model-questions-answers-1-320.jpg)
![Q. Enumerate the different steps in cholinergic transmission, in the order of occurrence. Add a note on synthesis of acetylcholine in cholinergic nerve endings. 4 + 1 Cholinergic transmission Impulse conduction Arrival of impulse Synthesis, Storage & release of Ach by exocytosis Combination of Ach With receptors Postjunctional activity: ,[object Object]](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)