• DR BADAR UDDIN UMAR
DRUGS ACTING ON THE ANS
ANTICHOLINESTERASE POISONING
ANTICHOLINERGIC DRUGS
LECTURE - 2
LEARNING OBJECTIVES:
At the end of this session the we shall be able to –
• Discuss the clinical features and drug treatme...
ORGANOPHOSPHORUS POISONING
• Poisoning with organophosphorus
compounds (OPCs) may occur by –
• Accidental exposure during ...
OPC POISONING
• Acetylcholine esterase enzymes (AChE) of the
body will be destroyed
• Covalent phosphorus-enzyme bond
• Ph...
ORGANOPHOSPHORUS COMPOUNDS
• Organophosphates are pentavalent phosphorus
compounds containing a labile group such as -
• F...
ORGANOPHOSPHORUS COMPOUNDS
• The inactive phosphorylated enzyme is usually
very stable
• When phosphorylated by OPCs, AChE...
ORGANOPHOSPHORUS COMPOUNDS
• Dyflos and parathion are volatile non-polar
substances of very high lipid solubility
• Are ra...
SIGNS AND SYMPTOMS OF OPC POISONING:
 All s/s are due to ….excessive level of Ach in the
body
 Muscarinic actions will l...
S/S OF OPC POISONING CONT.….
DUE TO MUSCARINIC ACTIONS…..
 Genito urinary - Urgency for urination and
spontaneous voiding...
SIGNS AND SYMPTOMS OF OPC POISONING
CONT.….
Nicotinic effects
• Fasciculation (early)
• Weakness (late)
• Paralysis
• Adre...
S/S OF OPC POISONING FOR EASY REMEMBERING:
DUMBBELLS…… stands for
• Diarrhea
• Urgency for Urination
• Miosis
• Bradycardi...
MANAGEMENT OF OPC POISONING:
The therapy of organophosphate poisoning is known
by the catchy acronym - AFLOP:
 Atropine
...
MANAGEMENT OF OPC POISONING:
General measures:
 Termination of exposure by -
 Removal of clothes etc. that are contamina...
MANAGEMENT OF OPC POISONING:
Drugs used in OPC poisoning:
A) Atropine:
 It is the antagonist of Ach
 It will block the M...
MANAGEMENT OF OPC POISONING:
Dose of atropine:
1-2 mg IM or IV immediately
Repeated 5-15 min…..until signs of atropiniza...
MANAGEMENT OF OPC POISONING:
B) Enzyme reactivator / regenerator
 Reactivate or regenerate AChE enzyme
 So AChE will be ...
MANAGEMENT OF OPC POISONING:
Oximes
 The oxime group (=NOH) has a high affinity for
phosphorous atom
 So, can hydrolyze ...
AGING
OF
ACETYLCHOLINESTERASE
LOSS OF AN ALKYL GROUP FROM PHOSPHORYLATED
ACHE “AGES” THE ENZYME
AChE, phosphorylated
and inhibited by DFP
“Aged” AChE
“AGING” OF PHOSPHORYLATED- ACHE
ADVERSE EFFECTS OF ATROPINE
ANTICHOLINERGIC DRUG
ADVERSE EFFECTS OF ATROPINE
• Dry mouth
• Blurred vision
• Tachycardia
• Constipation
• Urinary hesitancy and retention
• ...
CONTRAINDICATIONS OF ATROPINE….
• Glaucoma
• Elderly males with enlarged prostate
• Paralytic ileus
• Ulcerative colitis
•...
ATROPINE-LIKE DRUGS
• Atropine has got wide-spread effect
• So, it produces many side-effects
• There are some Atropine-li...
Atropine-like synthetic drugs
• These drugs have got more effect in that
specific purpose &
• has less side-effects than a...
ATROPINE-LIKE SYNTHETIC DRUGS
• Atropine-like Mydriatic drugs
• Atropine-like antispasmodic drugs
• Atropine-like antiasth...
ATROPINE-LIKE MYDRIATICS:
• Homatropine
• Eucatropine
• Cyclopentolate
• Tropicamide
ATROPINE-LIKE MYDRIATICS:
• Atropine-like synthetic drug
• Duration of action: shorter than atropine
• Effect of atropine ...
ATROPINE-LIKE MYDRIATICS:
Used in eye for …..
• Mydriasis for Funduscopic examination
• Accurate measurement of refractory...
ATROPINE-LIKE MYDRIATICS:
Homatropine
Duration : duration about 2-3 days
Cyclopentolate
• Duration : duration about 1 day
...
ATROPINE-LIKE MYDRIATICS:
• Now-a-days, antimuscarinics are less used for
opthalmoscopic examination if there is no need o...
ATROPINE-LIKE ANTISPASMODICS:
• Dicycloverine (Dicyclomine)
• Oxybutynin
• Propantheline
• Hyoscine butylbromide
ATROPINE-LIKE ANTISPASMODICS:
Dicycloverine (Dicyclomine)
• Tertiary amine
• More lipid soluble
• More absorbed
• More CNS...
ATROPINE-LIKE ANTISPASMODICS:
Propantheline
Hyoscine butylbromide
• Quaternary ammonium compound
• Less lipid soluble
• Le...
ATROPINE-LIKE ANTISPASMODICS:
These are selective … less side-effects
Mainly used for….
• Traveler's diarrhea
• Peptic ulc...
ATROPINE-LIKE ANTIASTHMATIC:
• Ipratropium
• Tiotropium (longer duration of action)
Selective effect in bronchus
• Used in...
ATROPINE-LIKE ANTIPARKINSONIC DRUGS:
• Benztropine
• Orphenadrine
• Procyclidine
Selective effect in brain
• Decreases Ach...
LEARNING OUTCOMES:
• At the end of this session the students will be able to –
• Discuss the clinical features and drug tr...
Anti cholinergics-2, aimst
Anti cholinergics-2, aimst
Anti cholinergics-2, aimst
Anti cholinergics-2, aimst
Anti cholinergics-2, aimst
Anti cholinergics-2, aimst
Anti cholinergics-2, aimst
Anti cholinergics-2, aimst
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Anti cholinergics-2, aimst

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Transcript of "Anti cholinergics-2, aimst"

  1. 1. • DR BADAR UDDIN UMAR DRUGS ACTING ON THE ANS ANTICHOLINESTERASE POISONING ANTICHOLINERGIC DRUGS LECTURE - 2
  2. 2. LEARNING OBJECTIVES: At the end of this session the we shall be able to – • Discuss the clinical features and drug treatment of organophosphorus poisoning • Explain the role of enzyme reactivators in organophosphorus poisoning • List and explain the adverse effects and contraindications of atropine • Discuss the aspects of pharmacokinetics, routes and dosage of clinically important/ commonly used drugs
  3. 3. ORGANOPHOSPHORUS POISONING • Poisoning with organophosphorus compounds (OPCs) may occur by – • Accidental exposure during spraying insecticides or in industry • Suicidal poisoning • Homicidal poisoning (rare) • War gas exposure
  4. 4. OPC POISONING • Acetylcholine esterase enzymes (AChE) of the body will be destroyed • Covalent phosphorus-enzyme bond • Phosphorylation • There will be massive (Acetylcholine) ACh accumulation in the body…….ACh toxicity
  5. 5. ORGANOPHOSPHORUS COMPOUNDS • Organophosphates are pentavalent phosphorus compounds containing a labile group such as - • Fluoride (in dyflos) or an • Organic group (in parathion and ecothiopate) • This group is released, leaving the serine hydroxyl group (-SH) of the enzyme phosphorylated
  6. 6. ORGANOPHOSPHORUS COMPOUNDS • The inactive phosphorylated enzyme is usually very stable • When phosphorylated by OPCs, AChE have no ability to hydrolyze ACh and • Recovery of enzymatic activity depends on the synthesis of new enzyme molecules • This may take weeks • With ecothiopate, slow hydrolysis occurs over the course of a few days, so that their action is not strictly irreversible
  7. 7. ORGANOPHOSPHORUS COMPOUNDS • Dyflos and parathion are volatile non-polar substances of very high lipid solubility • Are rapidly absorbed through mucous membranes and even through unbroken skin and insect cuticles • Due to this they can be used as war gases or insecticides
  8. 8. SIGNS AND SYMPTOMS OF OPC POISONING:  All s/s are due to ….excessive level of Ach in the body  Muscarinic actions will lead to-  Eye - Constricted pupils (Miosis), blurred vision, eye ache, conjunctival congestion, brow ache  Glands - Profuse Sweating, Salivation, Rhinorrhea & Lacrimation   GIT movement… Nausea, Vomiting, Diarrhea with abdominal cramps
  9. 9. S/S OF OPC POISONING CONT.…. DUE TO MUSCARINIC ACTIONS…..  Genito urinary - Urgency for urination and spontaneous voiding and penile erection (in severe case)  Bronchospasm, bronchial secretion Difficulty in breathing  Pulse rate/ Bradycardia  Hypotension  Collapse
  10. 10. SIGNS AND SYMPTOMS OF OPC POISONING CONT.…. Nicotinic effects • Fasciculation (early) • Weakness (late) • Paralysis • Adrenomedullary discharge (sympathetic, early and transient) CNS Effects • Anxiety • Insomnia • Nightmares • Confusion • Tremors • Convulsions • Respiratory depression • Circulatory collapse
  11. 11. S/S OF OPC POISONING FOR EASY REMEMBERING: DUMBBELLS…… stands for • Diarrhea • Urgency for Urination • Miosis • Bradycardia • Bronchospasm • Emesis • Lacrimation • Laxation and • Salivation
  12. 12. MANAGEMENT OF OPC POISONING: The therapy of organophosphate poisoning is known by the catchy acronym - AFLOP:  Atropine  Fluids  Oxygen  Pralidoxime
  13. 13. MANAGEMENT OF OPC POISONING: General measures:  Termination of exposure by -  Removal of clothes etc. that are contaminated  Washing the whole body  Gastric lavage  Cleaning the airways for easy respiration  Oxygen therapy and artificial respiration if needed  IV fluid for correction of dehydration and shock  IV Diazepam for convulsion
  14. 14. MANAGEMENT OF OPC POISONING: Drugs used in OPC poisoning: A) Atropine:  It is the antagonist of Ach  It will block the MR &  Will prevent the effects of Ach
  15. 15. MANAGEMENT OF OPC POISONING: Dose of atropine: 1-2 mg IM or IV immediately Repeated 5-15 min…..until signs of atropinization  Dryness of mouth  Reversal of miosis (mydriasis)  HR: above 70/min
  16. 16. MANAGEMENT OF OPC POISONING: B) Enzyme reactivator / regenerator  Reactivate or regenerate AChE enzyme  So AChE will be free again and metabolize ACh Oximes -  PAM (Pralidoxime) &  DAM (Diacetylmonoxime)
  17. 17. MANAGEMENT OF OPC POISONING: Oximes  The oxime group (=NOH) has a high affinity for phosphorous atom  So, can hydrolyze the phosphorylated AChE enzyme  Should be given within 12 hrs. of poisoning, after that can‟t be reversed (stabilized by ‘aging’)
  18. 18. AGING OF ACETYLCHOLINESTERASE
  19. 19. LOSS OF AN ALKYL GROUP FROM PHOSPHORYLATED ACHE “AGES” THE ENZYME AChE, phosphorylated and inhibited by DFP “Aged” AChE
  20. 20. “AGING” OF PHOSPHORYLATED- ACHE
  21. 21. ADVERSE EFFECTS OF ATROPINE ANTICHOLINERGIC DRUG
  22. 22. ADVERSE EFFECTS OF ATROPINE • Dry mouth • Blurred vision • Tachycardia • Constipation • Urinary hesitancy and retention • Atropine poisoning 25
  23. 23. CONTRAINDICATIONS OF ATROPINE…. • Glaucoma • Elderly males with enlarged prostate • Paralytic ileus • Ulcerative colitis • Gastroesophageal reflux • Tachycardia • Cardiac insufficiency 26
  24. 24. ATROPINE-LIKE DRUGS • Atropine has got wide-spread effect • So, it produces many side-effects • There are some Atropine-like synthetic drugs • which are used clinically for different conditions
  25. 25. Atropine-like synthetic drugs • These drugs have got more effect in that specific purpose & • has less side-effects than atropine
  26. 26. ATROPINE-LIKE SYNTHETIC DRUGS • Atropine-like Mydriatic drugs • Atropine-like antispasmodic drugs • Atropine-like antiasthmatic drugs • Atropine-like antiparkinsonic drugs
  27. 27. ATROPINE-LIKE MYDRIATICS: • Homatropine • Eucatropine • Cyclopentolate • Tropicamide
  28. 28. ATROPINE-LIKE MYDRIATICS: • Atropine-like synthetic drug • Duration of action: shorter than atropine • Effect of atropine lasts for about 1 week • Effects are like atropine but less side effects
  29. 29. ATROPINE-LIKE MYDRIATICS: Used in eye for ….. • Mydriasis for Funduscopic examination • Accurate measurement of refractory error…. Specially for un-cooperative patients & young children (ciliary paralysis is required) • Prevention of synechia (adhesion) formation in uveitis & iritis
  30. 30. ATROPINE-LIKE MYDRIATICS: Homatropine Duration : duration about 2-3 days Cyclopentolate • Duration : duration about 1 day Tropicamide • More shorter duration of action: 6 hrs.
  31. 31. ATROPINE-LIKE MYDRIATICS: • Now-a-days, antimuscarinics are less used for opthalmoscopic examination if there is no need of long lasting effect • Alpha-adrenergic stimulants (e.g., phenylephrine) are used for their short-lasting mydriatic effect, specially for funduscopic examination
  32. 32. ATROPINE-LIKE ANTISPASMODICS: • Dicycloverine (Dicyclomine) • Oxybutynin • Propantheline • Hyoscine butylbromide
  33. 33. ATROPINE-LIKE ANTISPASMODICS: Dicycloverine (Dicyclomine) • Tertiary amine • More lipid soluble • More absorbed • More CNS effect • Has some direct action on smooth muscle
  34. 34. ATROPINE-LIKE ANTISPASMODICS: Propantheline Hyoscine butylbromide • Quaternary ammonium compound • Less lipid soluble • Less absorbed • Less CNS effect • More appropriate as GIT antispasmodics
  35. 35. ATROPINE-LIKE ANTISPASMODICS: These are selective … less side-effects Mainly used for…. • Traveler's diarrhea • Peptic ulcer disease • Spasmodic pain in GIT • IBS (irritable bowel syndrome)
  36. 36. ATROPINE-LIKE ANTIASTHMATIC: • Ipratropium • Tiotropium (longer duration of action) Selective effect in bronchus • Used in bronchial asthma • Given by inhalation in bronchial Asthma
  37. 37. ATROPINE-LIKE ANTIPARKINSONIC DRUGS: • Benztropine • Orphenadrine • Procyclidine Selective effect in brain • Decreases Ach effect in basal ganglia • Decreases tremor, rigidity in parkinsonism
  38. 38. LEARNING OUTCOMES: • At the end of this session the students will be able to – • Discuss the clinical features and drug treatment of insecticide (organophosphorus) poisoning • Explain the role of enzyme reactivators and the importance of „aging‟ in organophosphorus poisoning • List the adverse effects and contraindications of atropine and explain the reasons of the same • Discuss the aspects of pharmacokinetics, routes and dosage of clinically important/ commonly used drugs like atropine
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