ANTI-CHOLINERGICS-2, AIMST

Views:
 
Category: Education
     
 

Presentation Description

No description available.

Comments

Presentation Transcript

Packager Shell Object:

DR BADAR UDDIN UMAR DRUGS ACTING ON THE Ans ANTICHOLINESTERASE POISONING Anticholinergic DRUGS Lecture - 2

Bitmap Image:

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

DRUGS ACTING ON THE Ans ANTICHOLINESTERASE POISONING Anticholinergic DRUGS Lecture - 2:

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

Learning Objectives::

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

Organophosphorus poisoning:

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

OPC Poisoning:

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

Organophosphorus COMPOUNDS:

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

Organophosphorus COMPOUNDS:

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

PowerPoint Presentation:

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

Signs and Symptoms of OPC poisoning::

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

s/s of opc poisoning cont.…. due to muscarinic actions…..:

S/S of OPC poisoning for easy remembering: DUMBBELLS…… stands for Diarrhea Urgency for Urination Miosis Bradycardia Bronchospasm Emesis Lacrimation Laxation and Salivation

Signs and Symptoms of OPC poisoning cont.….:

Management of OPC poisoning: The therapy of organophosphate poisoning is known by the catchy acronym - AFLOP: Atropine Fluids Oxygen Pralidoxime

S/S of OPC poisoning for easy remembering::

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

Management of OPC poisoning::

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

Management of OPC poisoning::

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

Management of OPC poisoning::

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)

Management of OPC poisoning::

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 ’)

PowerPoint Presentation:

AGING OF ACETYLCHOLINESTERASE

PowerPoint Presentation:

Loss Of An Alkyl Group From Phosphorylated Ache “Ages” The Enzyme AChE, phosphorylated and inhibited by DFP “Aged” AChE

AGING OF ACETYLCHOLINESTERASE :

“Aging” of Phosphorylated- AChE

Loss Of An Alkyl Group From Phosphorylated Ache “Ages” The Enzyme:

Adverse effects of atropine Anticholinergic drug

“Aging” of Phosphorylated- AChE :

Adverse effects of atropine Dry mouth Blurred vision Tachycardia Constipation Urinary hesitancy and retention Atropine poisoning 25

Adverse effects of atropine:

Contraindications of atropine…. Glaucoma Elderly males with enlarged prostate Paralytic ileus Ulcerative colitis Gastroesophageal reflux Tachycardia Cardiac insufficiency 26

Adverse effects of atropine:

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

Contraindications of atropine….:

Atropine-like synthetic drugs These drugs have got more effect in that specific purpose & has less side-effects than atropine

Atropine-like drugs:

Atropine-like synthetic drugs Atropine-like Mydriatic drugs Atropine-like antispasmodic drugs Atropine-like antiasthmatic drugs Atropine-like antiparkinsonic drugs

PowerPoint Presentation:

Atropine like Mydriatic drugs

Atropine-like synthetic drugs:

Atropine-like Mydriatics: Homatropine Eucatropine Cyclopentolate Tropicamide

PowerPoint Presentation:

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

Atropine-like Mydriatics::

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

Atropine-like Mydriatics::

Atropine-like Mydriatics: Homatropine Duration : duration about 2-3 days Cyclopentolate Duration : duration about 1 day Tropicamide More shorter duration of action: 6 hrs.

Atropine-like Mydriatics::

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

Atropine-like Mydriatics::

Atropine like Antispasmodic Drugs

Atropine-like Mydriatics::

Atropine-like antispasmodics: Dicycloverine (Dicyclomine) Oxybutynin Propantheline Hyoscine butylbromide

PowerPoint Presentation:

Atropine-like antispasmodics: Dicycloverine (Dicyclomine) Tertiary amine More lipid soluble More absorbed More CNS effect Has some direct action on smooth muscle

Atropine-like antispasmodics::

Atropine-like antispasmodics: Propantheline Hyoscine butylbromide Quaternary ammonium compound Less lipid soluble Less absorbed Less CNS effect More appropriate as GIT antispasmodics

Atropine-like antispasmodics::

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)

Atropine-like antispasmodics::

Atropine like Antiasthmatic Drugs

Atropine-like antispasmodics::

Atropine-like antiasthmatic: Ipratropium Tiotropium (longer duration of action) Selective effect in bronchus Used in bronchial asthma Given by inhalation in bronchial Asthma

PowerPoint Presentation:

Atropine like Antiparkinsonian drugs

Atropine-like antiasthmatic::

Atropine-like antiparkinsonic drugs: Benztropine Orphenadrine Procyclidine Selective effect in brain Decreases Ach effect in basal ganglia Decreases tremor, rigidity in parkinsonism

PowerPoint Presentation:

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

Atropine-like antiparkinsonic drugs::

Thank You

authorStream Live Help