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Cholinergic+antagonists+by+pharma+raptors
1. Presented By :
Aniket Kale
Pritesh Garodekar
Sakshi Korde
Achal Chandankhede
Session 2020-21
Guided by:
Prof.Pradnya Gondane
2. Introduction
Mechanism of action
Difference Between Quaternary & Tertiary
Antimuscarinic
Therapeutic Uses
Classification { Category 1-4 }
Structure & IUPAC Name
Synthesis
3. Antagonist :-
Drug having ability to bind the receptor (affinity) but do not have
abiltity to give therapeutic response (efficacy or intrinsic activity)
Parasympatholytics :-
Drugs that inhibit the parasympathetic system are called
parasympatholytics or anticholinergics.
Mimetic - shows same effect
Lytics - shows opposite effect
Cholinergic antagonist:-
Any drug that binds to but does not activate cholinergic
receptors, thereby blocking the actions of acetylcholine or
cholinergic agonists.
4.
Introduction :-
Parasympathetic postganglionic blocking agents are also
known as antimuscarinic, anticholinergic, parasympa tholytic,
or cholinolytic drug.
Choolinergic receptor blocking drugs or antagonists are
divided into muscarinic and nicotinic subgroups’ on the basis
of their specific receptor affinities.
The antinicotinic drugs consist of ganglion blockers and
neuromuscular junction blockers. The ganglion-blocking
drugs have little clinical use.
Muscarinic antagonists are often called as
parasympatholytics.
5. Muscarinic receptor antagonists prevent the effects of
acetylcholine by blocking its binding to muscarinic
cholinergic receptors at neuroeffector sites on smooth
muscles, cardiac muscles and gland cells; in peripheral
ganglia; and in the central nervous system.
In general, M receptor antagonists cause little effect on the
N receptor sites.There are naturally occurring compounds
with antimuscarinic effects that have been known and
used in medicines and cosmetics as well as in poisons.
6. • The drugs in this group antagonize the effects of
acetylcholine.Most of these drugs are antagonists
directly at the nicotinic or muscarinic receptor.Some
act on the channel associated with the nicotinic
receptor and still others block acetylcholine release.
• Competitve antagonists
• Compete with Ach
• Block Ach at muscarinic receptor in the
parasympathetic nervous system. As a result,Ach is
unable to bind the receptor site cause a cholinergic
effect.
7.
8. Once these drugs bind to receptors they inhibit the
nerve transmission at receptors.
9. There are three predictable and
clinically useful results from blocking the muscarinic
effects of ACh.
1. Mydriatic effect: dilation of the pupil of the eye; and
cycloplegia, a paralysis of the ciliary structure of the
eye, resulting in a paralysis of accommodation for near
vision.
2. Antispasmodic effect: lowered tone and motility of the
GI tract and genitourinary tract.
3.Antisecretory effect: reduced salivation
(antisialagogue),
reduced perspiration (anhidrotic), and reduced acid and
gastric secretion
10. Quaternary Amines
• These drugs do not pass through the blood brain barrier, and
hence, lack CNS actions.
• Penetrate poorly into the eye from the blood stream or
cornea.
• The quaternary compounds have greater affi nity for nicotinic
receptors, so that a great degree of ganglionic blockade may
result.
• These are mostly excreted unchanged into the urine.
11. Tertiary Amines:-
• These drugs can penetrate the cell membranes in the
nonionized form, and hence, can pass through the blood
brain barrier. In the brain, they can exert both therapeutic
and toxic actions.
• These drugs penetrate through the cornea and cause
mydriasis and cycloplegia.
• They do not have nicotinic receptor affinity.
• These drugs are biotransformed in the liver.
12. Therapeutic Uses
1.Used topically to dilate the pupil and paralyze
accommodation.
2.Used as a preanaesthetic medication, to inhibit excessive
salivary, bronchial secretions, and to prevent bronchospasm
and laryngospasm.
3.The antisecretory effects are also sought in the treatment
of hay fever, and rhinitis.
4.Used in the treatment of bronchial asthma and peptic
ulcer.
5. Used in the treatment of Parkinson’s disease.
13. I. Solanaceous alkaloids and analogues
i. Atropine
ii. Scopolamine (Hyoscine)
iii. Homatropine
II. Amino alcohols
iv
i .B
Ip
ip
ra
etr
io
dp
ei
n
um bromide
ii. Procyclidine HCl
iii. Trihexyl phenidyl
14. Ill.Amino alcohol esters
i. Cyclopentolate
ii. Clidinium
iii. Dicyclomine
iv. Eucatropine HCl
v.Glycopyrrolate bromide
vi.Methantheline bromide
vii.Propantheline bromide
IV. Amino ethers
i. Orphenadrine citrate
ii. Benztropine mesylate
15. Structure and IUPAC
I. Solaneous alkaloids and analogues:-
1. Atropine
8-methyl-8- azabicyclo[3.2.1]oct-3-yl) 3-hydroxy-2-
phenylpropanoate
20. • Properties and uses: It is a white or almost white crystalline
powder, freely soluble in methanol, soluble in water, but slightly
soluble in ethanol. It is used in the inhalation therapy to produce
dilation of bron chial smooth muscle for acute asthmatic
attacks. It produces broncho-dilation by competitive inhibition of
cholinergic receptors bound to the smooth muscles of the
bronchioles.
• Assay: Dissolve the sample in water and add 3 ml of dilute nitric
acid. Titrate with 0.1 M silver nitrate and determine the end point
potentiometrically.
• Dose: For inhalation reversible airways obstruction and COPD,
maximum dose is 320 μ
g daily as nebulized solution.
• Dosage forms: Ipratropium Nebuliser solution B.P., Ipratropium
powder for inhalation B.P., Ipratropium pressurized inhalation
B.P.
