Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.
ANTICHOLINERGIC DRUGS
Presented by:
Dr. Vishal
kr. Kandhway
ANTICHOLINERGIC DRUGS
Anti cholinergic drugs
Are those which antagonise the effect of neurotransmitter
Acetylcholine (ACh)...
• Nicotinic acetyl choline receptor site-
– Nerve endings of neuromuscular junction.
• Acetylcholine is also the neurotran...
Naturally Occurring (Tertiary Amine)
Atropine Scopolamine
(Alkaloids of belladonna plants
Synthetic compound
(Glycopyrrola...
Classification
• Natural alkaloid – Atropine,
Scopolamine(hyoscine)
• Semi-synthetic derivative – Homatropine,
Atropine mi...
Quarternary : Glycopyrolate, Propantheline,
Isopropamide.
Tertiary amines : Pirenzepine, Dicyclomine
c)Vasicoselective : O...
Mechanism of action
• Anticholinergic are the class of drugs that
block the neurotransmitter acetylcholine in
CNS and PNS....
Muscarinic Receptor Subtypes
M1 M2 M3 M4 M5
Location • CNS
• Stomach
• Heart
• CNS
• Airway
Smooth
Muscle
• CNS
• Salivary...
Atropine
• Atropine sulphate is a tertiary amine & the
naturally occuring levorotatory form is active.
• Administered IV/I...
Pharmacological Actions
• CNS :
-Atropine has CNS stimulant action. However
these effects are not appriciable at low doses...
• CVS :
- Most prominent effect is to cause tachycardia
due to blockade of M2 receptors at SA node.
• Eye :
- Topical inst...
• Smooth muscles :
- All visceral smooth muscles that receive
parasympathetic motor innervation are relaxed
by atropine du...
• Glands :
- Atropine markedly decreases sweat, salivary,
tracheobronchial & lacrimal secretions by M3
blockade.
- Skin & ...
• Sensitivity of different organs & tissues to
atropine varies & can be graded as –
• Saliva, sweat, bronchial secretion >...
Uses
• As anti-secretory :
- Pre-anesthetic medication : reduces excessive
salivation & respiratory secretions.
- Peptic u...
• Can be given in patients of Bronchial Asthma
• As mydiatric & cycloplegic.
• As cardiac vagolytic
• For central actions ...
Side effects
• Belladona poisoning due to drug overdose.
• Dry mouth, difficutly in swallowing and talking.
• Dry ,flushed...
• Treatment :
Physostigmine 15- 60 micro gram / kg IV every
1- 2 hourly.
• Contraindications :
- Narrow angle glaucoma
- B...
Glycopyrolate
• Glycopyrolate is a synthetic product that differs from
atropine in being a quaternary amine.
• The pre-med...
Scopolamine
• Scopolamine is a naturally occuring tertiary amine.
• It’s dose is 0.3-0.5 micro gram I/M.
• Clinical Consid...
Differences
Atropine Glycopyrrolate
1. Lipid solubility - Lipid soluble - Poorly soluble (Quaternary
ammonium compound)
2....
Differences
Atropine Glycopyrrolate
7. Effect on smooth
muscles
Decreases tone of smooth
muscles of biliary tract & ureter...
Comparative effects of anticholinergic drugs
Sedation Antisialagogue Increase Heart
Rate
Relax smooth
Muscles
Atropine + +...
Central Anticholinergic Syndrome
• Anticholinergic drugs like scopolamine, atropine can
enter central nervous system (CNS)...
• References :-
Stoelting’s Pharmacology & Physiology.
Morgan & Mikhail’s Clinical Anesthesiology.
KD Tripathi Essentials ...
THANK YOU
Upcoming SlideShare
Loading in …5
×

Anticholinergic drugs

A summary of anticholinergic drugs i/v/o anaesthesia importance

Related Books

Free with a 30 day trial from Scribd

See all

Related Audiobooks

Free with a 30 day trial from Scribd

See all
  • Be the first to comment

Anticholinergic drugs

  1. 1. ANTICHOLINERGIC DRUGS Presented by: Dr. Vishal kr. Kandhway
  2. 2. ANTICHOLINERGIC DRUGS Anti cholinergic drugs Are those which antagonise the effect of neurotransmitter Acetylcholine (ACh) on autonomic effectors & in the CNS exerted through “Muscarinic receptors”. Though nicotinic antagonists also block certain actions of Ach, they are referred to as “Ganglion blockers” & “Neuromuscular blockers” • Muscarinic receptor site- • Heart • Salivary glands • Smooth muscles of GIT • Genitourinary tract • Urinary bladder
  3. 3. • Nicotinic acetyl choline receptor site- – Nerve endings of neuromuscular junction. • Acetylcholine is also the neurotransmitter at postganglionic nicotinic receptors located at the NMJ (Neuromuscular junction) & autonomic ganglia. • Effects of anticholinergic drugs at nicotinic cholinergic receptors is little / nil as compared at muscarinic receptors. • Anticholinergic drugs are considered – selectively antimuscarinic.
  4. 4. Naturally Occurring (Tertiary Amine) Atropine Scopolamine (Alkaloids of belladonna plants Synthetic compound (Glycopyrrolate) (Quaternery Ammoniums Derivatives) • More potent than parent compounds • Lack CNS activity because of poor penetration in brain
  5. 5. Classification • Natural alkaloid – Atropine, Scopolamine(hyoscine) • Semi-synthetic derivative – Homatropine, Atropine mithonitrate, Ipratropium bromide. • Synthetic compound – a) Mydriatics : Cyclopentolate, tropicamide b)Anti-seceretory -
  6. 6. Quarternary : Glycopyrolate, Propantheline, Isopropamide. Tertiary amines : Pirenzepine, Dicyclomine c)Vasicoselective : Oxybutynin, flavoxate. d)Anti-parkinsonian : Benzhexol, biperiden.
  7. 7. Mechanism of action • Anticholinergic are the class of drugs that block the neurotransmitter acetylcholine in CNS and PNS. • Anticholinergic drugs combine reversibly with muscarinic cholinergic receptors thus preventing access of neurotransmitter acetylcholine in these sites.
  8. 8. Muscarinic Receptor Subtypes M1 M2 M3 M4 M5 Location • CNS • Stomach • Heart • CNS • Airway Smooth Muscle • CNS • Salivary glands • Airway smooth muscle • Vascular endothelial cells • CNS • Heart • CNS Clinical Effects • Hydrogen Ion Secretion • Bradycardia • Salivation • Bronchodilati on • Vasodilation ? ? Clinically selective drugs available Yes No No No No
  9. 9. Atropine • Atropine sulphate is a tertiary amine & the naturally occuring levorotatory form is active. • Administered IV/IM in a range of 0.01-0.02 mg/kg upto adult dose of 0.4-0.6 mg. • Larger IV doses upto 2 mg may be required to completely block the cardiac vagal nerves in treating severe bradycardia.
  10. 10. Pharmacological Actions • CNS : -Atropine has CNS stimulant action. However these effects are not appriciable at low doses. -Atropine stimulates many medullary centres – vagal, respiratory, vasomotor. - It depresses vestibular exitation and has anti- motion sickness property. - It supresses tremor & rigidity of parkinsonism. - High doses cause cortical exitation, restlessness, disorientation, hallucination & delirium followed by respiratory depression & coma.
  11. 11. • CVS : - Most prominent effect is to cause tachycardia due to blockade of M2 receptors at SA node. • Eye : - Topical instillation of atropine causes mydriasis, abolition of light reflex and cycloplegia resulting in photophobia & blurring of near vision.
  12. 12. • Smooth muscles : - All visceral smooth muscles that receive parasympathetic motor innervation are relaxed by atropine due to M3 blockade. - Tone & amplitude of contractions of stomach & intestine are reduced, the passage of chyme is slowed – constipation may occur & spasm may be relieved. - Atropine causes bronchodilatation & reduces airway resistance especially in COPD & Asthma patients. - Atropine has relaxant action on ureter & urinary bladder.
  13. 13. • Glands : - Atropine markedly decreases sweat, salivary, tracheobronchial & lacrimal secretions by M3 blockade. - Skin & eyes become dry, talking & swallowing may be difficult. • Body temperature : - Rise in body temperature occur at high doses due to both inhibition of sweating as well as stimulation of temperature regulating centre in the hypothalamus. - Children are highly succeptible to Atropine fever. • Local anaesthetic : Atropine has mild anesthetic action on the cornea.
  14. 14. • Sensitivity of different organs & tissues to atropine varies & can be graded as – • Saliva, sweat, bronchial secretion > eye, bronchial muscle, heart > smooth muscle of intestine, bladder > gastric glands & smooth muscles.
  15. 15. Uses • As anti-secretory : - Pre-anesthetic medication : reduces excessive salivation & respiratory secretions. - Peptic ulcer : decreses gastric secretions & provide symptomatic relief in peptic ulcer now been superseded by H2 blockers. • As anti-spasmodic : - If there is no mechanical obstruction intestinal & renal colic, abdominal cramps symptomatic relief is affordable. - Gastritis, gastric hypermortility. - To relive urinary frequency & urgency.
  16. 16. • Can be given in patients of Bronchial Asthma • As mydiatric & cycloplegic. • As cardiac vagolytic • For central actions in Parkinsonism as an adjuvant to levodopa. • To antagonise muscarinic effects of anti- Cholinesterase i.e OP Poisoning with dose 2mg IV with repeated doses and early mushroom poisoning.
  17. 17. Side effects • Belladona poisoning due to drug overdose. • Dry mouth, difficutly in swallowing and talking. • Dry ,flushed and hot skin. • Fever difficulty in micturition , decreased bowel sounds. • Dilated pupil, photophobia, blurring of near vision. • Excitement, ataxia, delirium, hallucination. • Convulsion and coma may occur in severe poisoning.
  18. 18. • Treatment : Physostigmine 15- 60 micro gram / kg IV every 1- 2 hourly. • Contraindications : - Narrow angle glaucoma - BPH - Hyperthyroidism - CAD
  19. 19. Glycopyrolate • Glycopyrolate is a synthetic product that differs from atropine in being a quaternary amine. • The pre-medication dose is 0.005 – 0.01 mg/kg upto 0.2-0.3 mg in adults. • Clinical consideration : • Because of its quaternary structure, glycopyrolate can’t cross BBB & is almost devoid of CNS & Opthalmic activity. • Potent inhibition of salivary gland & respiratory tract secretions is the primary rationale for using glycopyrolate as pre-medication. • Heart rate increases after IV administration. • It has longer duration of action than atropine sulphate i.e 2- 4 hrs.
  20. 20. Scopolamine • Scopolamine is a naturally occuring tertiary amine. • It’s dose is 0.3-0.5 micro gram I/M. • Clinical Consideration : • Lipid soluble. • Easy penetrate BBB. • More potent antisialagogue than Atropine & causes greater CNS effects • Clinical doses results in restlessness, drowsiness, amnesia, dizziness & delirium. • It has the added virtue of preventing motion sickness. • The lipid solubility allows trans-dermal absorption & has been used to prevent post-operative nausea & vomiting • Best avoided in patients with closed angle glaucoma.
  21. 21. Differences Atropine Glycopyrrolate 1. Lipid solubility - Lipid soluble - Poorly soluble (Quaternary ammonium compound) 2. Blood brain barrier crossing - Good - Minimum ability of crossing BBB 3. Metabolization - 50% from liver - 4. Excretion - 18% unchanged - 80% unchanged 5. Treatment - bradycardia at low dose - 0.2 – 0.4 mg IV -Dose for intra operative bradycardia 1.2 mg -Max dose for bradycardia 3 mg Hiccups (Occurring after laryngeal mask placement) Intra operative bradycardia
  22. 22. Differences Atropine Glycopyrrolate 7. Effect on smooth muscles Decreases tone of smooth muscles of biliary tract & ureter 8. Antisialagauge effect - Less then scopolamine More 9. T½ - 2.3 hrs Prolonged in uremic patients 1.25 hrs
  23. 23. Comparative effects of anticholinergic drugs Sedation Antisialagogue Increase Heart Rate Relax smooth Muscles Atropine + + +++ ++ Scopolamine +++ +++ + + Glycopyrrolate 0 ++ ++ ++ Mydriasis cycloplegia Prevent Motion induced Nausea Decrease Gastric Hydrogen Ion secretion Alter Fetal Heart Rates Atropine + + + 0 Scopolamine +++ +++ + ? Glycopyrrolate 0 0 + 0
  24. 24. Central Anticholinergic Syndrome • Anticholinergic drugs like scopolamine, atropine can enter central nervous system (CNS) and produce some unusual symptoms which are characterized in a syndrome which is known as central anticholinergic syndrome. Symptoms are - – Restlessness – Hallucination to somnolence – Unconsciousness Glycopyrrolate does not easily cross BBB & not likely cause CACS.
  25. 25. • References :- Stoelting’s Pharmacology & Physiology. Morgan & Mikhail’s Clinical Anesthesiology. KD Tripathi Essentials of Medical Pharmacology.
  26. 26. THANK YOU

×