際際滷

際際滷Share a Scribd company logo

Anticholinergic Drugs

Download as PPTX, PDF
Dr.Ravi K Sori
Dr.Ravi K Sori

This document discusses anticholinergic drugs, which are muscarinic receptor blockers that inhibit the actions of acetylcholine. It classifies anticholinergics as natural alkaloids like atropine, semisynthetic derivatives, and synthetic compounds. Atropine is the prototype drug and works by competitively blocking muscarinic receptors. Clinically, atropine causes dry mouth, blurred vision, difficulty swallowing and talking, increased heart rate, decreased gastrointestinal and bronchial secretions, and elevated body temperature. Its substitutes have similar but longer-lasting effects. Common uses include pre-anesthesia, peptic ulcers, asthma, and Parkinson's disease. Atropine poisoning can be

1 of 37
Downloaded 86 times
Anticholinergics Dr. Ravi K. Sori
Anticholinergic drugs Muscarinic receptors blockers / Parasympatholytics Block the actions of ACh on autonomic effectors & in the CNS exerted through Muscarinic receptors
Classification Natural alkaloids - Atropine Hysocine (scopolamine) Semisynthetic derivatives - Homatropine Atropine methonitrate Hyocine butyl bromide Ipratropium bromide Tiotropium bromide
Classification Synthetic compounds:- Mydriatics - Cyclopentolate, Tropicamide Antisecretory Antispasmodics - Quaternary compounds - Propanthaline Oxyphenonium Clidinium, Pipenzolate methyl bromide Glycopyrrolate
Tertiary amines - Dicyclomine Oxybutynin Flavoxate Pirenzepine Telenzepine
Antiparkinsonion - Trihexyphenidyl (Benzhexol) Procyclindine Bipridine Benztropine
Atropine Prototype Drug Atropine Atropa Belladonna - Deadly Nightshade Greek God Cutting the thread of life Beautiful Lady
Cutting the thread of life Deadly Nightshade has been used for such noble purposes as poisoning enemy troops (the Ancient Romans were particularly good at this), for torture, for its hallucinogenic properties, and to Kill the enemy
Beautiful Lady Deadly Nightshade was also used in cosmetics - the sap was used by Italian women to dilate their pupils, which made them appear more attractive
Mechanism of Action Atropine and related compounds compete with ACh and other muscarinic agonists for a common binding site on the muscarinic receptors Since antagonism by atropine is competitive
Pharmacological Actions
CNS Atropine at therapeutic doses, causes a mild stimulation of medullary and higher cerebral centres Bradycardia and increase in the rate & depth of respiration Blocks the cholinergic over activity in ganglia - supresses tremor & rigidity of parkinsonism High dose - cortical excitation, restlessness, hallucinations and delirium followed by respiratory depression and coma
CVS With higher dose of atropine , the cardiac receptors on the SA node ( M2) are blocked and the cardiac rate increases (Tachycardia) Atropine does not have any marked effect on BP
Smooth Muscles Eyes Topical instillation of atropine - Mydriasis by blocking M3 receptors in sphincter pupillae of the iris Cycloplegia - Ciliary muscles are paralyzed
Gastrointestinal tract reduces both the tone and motility of all parts GI tract. Bronchi Atropine relaxes the smooth muscle of the bronchi and bronchioles- bronchodilatation also inhibits the mucociliary clearance
Urinary tract- retention of urine Uterus- No significant effect on the tone and motility of the uterine smooth muscle
Glands Atropine markedly decreases sweat, salivary , tracheobronchial and lacrymal secretions Skin becomes dry, talking and swallowing may be difficult Primarily reduces the volume and the total acidity of gastric secretion by decreasing the secretion of acid, pepsin and mucin
Body Temperature Rise in body temperature Occurs at higher doses due to inhibition of sweating and stimulation of temperature regulating center in hypothalamus
Common features of Atropine Substitutes Incomplete oral absorption They do not penetrate to brain and eye. So the central and ocular effect is not seen after parenteral or oral administration Elimination is generally slower and are longer acting Have higher nicotinic blocking property Some Ganglionic blockade may occur at clinical doses - postural hypotension, impotence At high doses - neuromuscular blockade may occur
Hyoscine butyl bromide - Used for esophageal and gastrointestinal spastic condition Atropine methonitrate - Used for abdominal colics and hyperacidity Also used in bronchial asthma and asthmatic bronchitis
Ipratropium bromide It acts selectively on bronchial muscle without altering volume or consistency of respiratory secretion It does not depress mucociliary clearance by bronchial epithelium It acts on receptors located mainly in the larger central airways It is more effective in bronchial asthma
Tiotropium bromide Congener of ipratropium bromide, binds very tightly to the bronchial M3 receptor - long lasting bronchodilator
Flavoxate Direct relaxant action on smooth muscle - urinary frequency and urge incontinence Pirenzepine It selectively blocks M1 muscarinic receptors It inhibits gastric secretion . Used in peptic ulcer Telenzepine It is analog of Pirenzepine that has higher potency and similar action
Mydriatics Homatropine ten times less potent than atropine used as mydriatic in adults, but often produces unsatisfactory cycloplegia in children Cyclopentolate It is potent rapidly acting Mydriasis and cycloplegia occur in 30-60 min
Tropicamide It has quickest and briefest action It is satisfactory for refraction testing in adults & in fundoscopy
CLINICAL USES
Antisecretory Pre anesthetic medication Peptic ulcer To check excessive sweating or salivation - Sialorrrhoea
Antispasmodic Intestinal and renal colic, abdominal cramps - Dysmenorrhea Nervous and drug induced diarrhea, functional diarrhea Spastic constipation, irritable colon Pylorospasm, gastric hyper motility, gastritis
Bronchial asthma, COPD As Mydriatic and cycloplegic As Cardiac vagolytic - AV block For central action - anti-motion sickness & Parkinsonism - Benztropine Park my Benz To antagonize Muscarinic effect of drugs and poisons
Anticholinergic Drugs
Anticholinergic Drugs
Anticholinergic Drugs
Atropine/Belladonna Poisoning Drug overdose, consumption of seeds and berries of belladonna/datura plant Manifestations are due to exaggerated pharmacological actions
Anticholinergic Drugs
Diagnosis Methacholine 5mg or neostigmine 1mg s.c. fails to induce typical muscarinic effects
Treatment If poison has been ingested, gastric lavage should be done with tannic acid The patient should be kept dark room Cold sponging or ice bags are applied for reducing body temperature Diazepam to control convulsions Physostigmine - 1-3 mg s.c. or i.v. to antagonizes both central and peripheral effects It may be repeated 4-6 hourly
37

More Related Content

Anticholinergic Drugs

  • 2. Anticholinergic drugs Muscarinic receptors blockers / Parasympatholytics Block the actions of ACh on autonomic effectors & in the CNS exerted through Muscarinic receptors
  • 3. Classification Natural alkaloids - Atropine Hysocine (scopolamine) Semisynthetic derivatives - Homatropine Atropine methonitrate Hyocine butyl bromide Ipratropium bromide Tiotropium bromide
  • 4. Classification Synthetic compounds:- Mydriatics - Cyclopentolate, Tropicamide Antisecretory Antispasmodics - Quaternary compounds - Propanthaline Oxyphenonium Clidinium, Pipenzolate methyl bromide Glycopyrrolate
  • 5. Tertiary amines - Dicyclomine Oxybutynin Flavoxate Pirenzepine Telenzepine
  • 6. Antiparkinsonion - Trihexyphenidyl (Benzhexol) Procyclindine Bipridine Benztropine
  • 7. Atropine Prototype Drug Atropine Atropa Belladonna - Deadly Nightshade Greek God Cutting the thread of life Beautiful Lady
  • 8. Cutting the thread of life Deadly Nightshade has been used for such noble purposes as poisoning enemy troops (the Ancient Romans were particularly good at this), for torture, for its hallucinogenic properties, and to Kill the enemy
  • 9. Beautiful Lady Deadly Nightshade was also used in cosmetics - the sap was used by Italian women to dilate their pupils, which made them appear more attractive
  • 10. Mechanism of Action Atropine and related compounds compete with ACh and other muscarinic agonists for a common binding site on the muscarinic receptors Since antagonism by atropine is competitive
  • 12. CNS Atropine at therapeutic doses, causes a mild stimulation of medullary and higher cerebral centres Bradycardia and increase in the rate & depth of respiration Blocks the cholinergic over activity in ganglia - supresses tremor & rigidity of parkinsonism High dose - cortical excitation, restlessness, hallucinations and delirium followed by respiratory depression and coma
  • 13. CVS With higher dose of atropine , the cardiac receptors on the SA node ( M2) are blocked and the cardiac rate increases (Tachycardia) Atropine does not have any marked effect on BP
  • 14. Smooth Muscles Eyes Topical instillation of atropine - Mydriasis by blocking M3 receptors in sphincter pupillae of the iris Cycloplegia - Ciliary muscles are paralyzed
  • 15. Gastrointestinal tract reduces both the tone and motility of all parts GI tract. Bronchi Atropine relaxes the smooth muscle of the bronchi and bronchioles- bronchodilatation also inhibits the mucociliary clearance
  • 16. Urinary tract- retention of urine Uterus- No significant effect on the tone and motility of the uterine smooth muscle
  • 17. Glands Atropine markedly decreases sweat, salivary , tracheobronchial and lacrymal secretions Skin becomes dry, talking and swallowing may be difficult Primarily reduces the volume and the total acidity of gastric secretion by decreasing the secretion of acid, pepsin and mucin
  • 18. Body Temperature Rise in body temperature Occurs at higher doses due to inhibition of sweating and stimulation of temperature regulating center in hypothalamus
  • 19. Common features of Atropine Substitutes Incomplete oral absorption They do not penetrate to brain and eye. So the central and ocular effect is not seen after parenteral or oral administration Elimination is generally slower and are longer acting Have higher nicotinic blocking property Some Ganglionic blockade may occur at clinical doses - postural hypotension, impotence At high doses - neuromuscular blockade may occur
  • 20. Hyoscine butyl bromide - Used for esophageal and gastrointestinal spastic condition Atropine methonitrate - Used for abdominal colics and hyperacidity Also used in bronchial asthma and asthmatic bronchitis
  • 21. Ipratropium bromide It acts selectively on bronchial muscle without altering volume or consistency of respiratory secretion It does not depress mucociliary clearance by bronchial epithelium It acts on receptors located mainly in the larger central airways It is more effective in bronchial asthma
  • 22. Tiotropium bromide Congener of ipratropium bromide, binds very tightly to the bronchial M3 receptor - long lasting bronchodilator
  • 23. Flavoxate Direct relaxant action on smooth muscle - urinary frequency and urge incontinence Pirenzepine It selectively blocks M1 muscarinic receptors It inhibits gastric secretion . Used in peptic ulcer Telenzepine It is analog of Pirenzepine that has higher potency and similar action
  • 24. Mydriatics Homatropine ten times less potent than atropine used as mydriatic in adults, but often produces unsatisfactory cycloplegia in children Cyclopentolate It is potent rapidly acting Mydriasis and cycloplegia occur in 30-60 min
  • 25. Tropicamide It has quickest and briefest action It is satisfactory for refraction testing in adults & in fundoscopy
  • 27. Antisecretory Pre anesthetic medication Peptic ulcer To check excessive sweating or salivation - Sialorrrhoea
  • 28. Antispasmodic Intestinal and renal colic, abdominal cramps - Dysmenorrhea Nervous and drug induced diarrhea, functional diarrhea Spastic constipation, irritable colon Pylorospasm, gastric hyper motility, gastritis
  • 29. Bronchial asthma, COPD As Mydriatic and cycloplegic As Cardiac vagolytic - AV block For central action - anti-motion sickness & Parkinsonism - Benztropine Park my Benz To antagonize Muscarinic effect of drugs and poisons
  • 33. Atropine/Belladonna Poisoning Drug overdose, consumption of seeds and berries of belladonna/datura plant Manifestations are due to exaggerated pharmacological actions
  • 35. Diagnosis Methacholine 5mg or neostigmine 1mg s.c. fails to induce typical muscarinic effects
  • 36. Treatment If poison has been ingested, gastric lavage should be done with tannic acid The patient should be kept dark room Cold sponging or ice bags are applied for reducing body temperature Diazepam to control convulsions Physostigmine - 1-3 mg s.c. or i.v. to antagonizes both central and peripheral effects It may be repeated 4-6 hourly
  • 37. 37