MODULE 8: DRUGS ACTING ON AUTONOMIC NERVOUS SYSTEM (PART 1)

Parasympathomimetic and parasympatholytic

Choline

a member of the B-complex, when a person lacks b-complex, they experience pamamanhid, tusok-tusok.

Methacholine

Act primarily on the muscarinic receptor.

More active on the heart, less action on the muscarinic receptor of gastrointestinal tract and urinary tract.

Bethanechol

More active on the muscarinic receptor of the gastrointestinal tract and urinary tract less active in the muscarinic receptor of the heart.

carbachol

Act on both nicotinic and muscarinic gastrointestinal tract and urinary tract.

More on both nicotinic and gastrointestinal tract and urinary tract.

Drugs acting on the parasympathomimetic action on the respiratory system

Constriction

Drugs acting on the parasympathomimetic action on cardiovascular system

Decreases the function of heart

Drugs acting on the parasympathomimetic action on gastro-intestinal tract

contraction therefore it increases peristaltic movement.

Drugs acting on the parasympathomimetic action on the eye

Contraction in the muscle of the eye.

Drugs acting on the parasympathomimetic action in the urinary bladder

Contraction

Choline esters causes

profuse sweating in horses in evoked by carbachol

Methacholine

Drug of choice for Raynaud’s disease.

Treatment of tachycardia of supraventricular origin.

Bethanecol

Treatment for urinary bladder atony in cats

Atony

Without normal contraction/movement

Nawawalan ng lakas ang muscle para mag contract.

Carbachol

Treatment for colic (abdominal pain)

Treatment for impaction

Treatment of rumen atony

Pilocarpine

A naturally occurring cholinomimetic alkaloids that is used as treatment for glaucoma and synechia

Synechia

there is an abdominal adhesion from one layer to the other layer.

Iridocyclitis

Contraindications of pilocarpine.

Fyi: iridocyclitis is the inflammation or iris and ciliary body pilocarpine shouldn’t be used.

Arecoline

Treatment for taeniacide (tapeworm)

Parasympathethic/ Cholinergic

Direct-acting parasympathomimetic

Naturally occurring cholinomimetic alkaloids

Direct acting parasympathomimetic

Methacholine

Bethanechol

carbachol

Naturally occurring cholinomimetic alkaloids

Pilocarpine

Arecoline

Muscarine

Cholinesterase inhibitors

Reversible inhibitors

Irreversible inhibitors

reversible inhibitors

a Cholinesterase inhibitor that Binds temporarily to the cholinesterase enzyme.

Physostigmine

From the plant Physostigmine venosum (calabar or ordeal bean)

Synthetics of Physostigmine

Neostigmine

Edrophonium

Pyridostigmine

Ambenomium

Physostigmine

A reversible inhibitor of cholinesterase inhibitor that is used in treatment for glaucoma, synechia, and impaction.

Neostigmine

A reversible inhibitor of cholinesterase inhibitor that is used in treatment for Myasthenia gravis/ Grandmal in dogs.

Myasthenia gravis

Muscle weakness throughout the body.

Irreversible inhibitors

A cholinestrase inhibitor that binds with enzyme irreversibly is permanent.

malathion

An irreversible inhibitor that is a n oregano Phosphorus - compounds that is removed due to bad effects in the environment

Parathion

An irreversible inhibitor that is a n oregano Phosphorus - compounds that is the same as malathion but is still in question.

This is the prototype

Dichlorvos, trichlorphon. haloxan

These are organo phosphorus - compounds that is available.

Common signs of poisoning / toxicosis

Vomiting

Salivation

Diarrhea

Seizure

Bradycardia

Atropine sulfate

This is given as initial treatment when there is toxicosis which inhibits salivation, and control spasm.

Pralidoxime or 2-pam

To separate the irreversible enzyme and cholinesterase enzyme during toxicosis

Para sympatholytic/ Anticholinergic drugs

Drug that inhibit the action of the parasympathetic nerve by competing for the muscarinic receptor.

A.K.A muscarinic blocking drugs

Atropine and scopolamine

From plant Astropa belladoma according to the old books.

Maybe produced from Datura stramonium and Hyoseyamus niger

Causes tachycardia and vasodilation of blood vessels

The cause of atropine and scopolamine in cardiovascular system.

Relaxes the G.I. tract

The cause of atropine and scopolamine in GIT.

Dilation of respiratory system

What is the cause of atropine and scopolamine in respiratory system.

Mydriasis

What is the cause of atropine and scopolamine in ocular/ eyes.

Relaxation

What is the cause of atropine and scopolamine in urinary bladder.

Twilight sleep: analgesia and amnesia

What is the side effect of scopolamine + morphine?

Atropine and scopolamine

This drug is under parasympatholytic that is used in treatment of smooth muscle spasm, spasmolytic.

Used as pre-anesthetic, adjunct anesthetic.

Treatment for 2nd degree heart block caused by xylazine.

Used for opthalmic exam.

Used as antidote to anticholinesterase poisoning.

Atropine and scopolamine (alkaloid)

synthetic drugs: Glycopyrrolate, Homatropine, Methanteline, Propantheline, Methylatropine

A parasympatholytic drug that competes for the muscarinic receptor.

Glycopyrrolate

A synthetic muscarinic blocking drug that does not cause tachycardia.

Homatropine

A synthetic muscarinic blocking drug that is almost the same as atropine but there is a change in ester in which it contains mandelic acid instead of tropic acid.

methylastropine

A synthetic muscarinic blocking drug that almost the same as atropine but it has a methyl group.

A parasympatholytic Synthetic muscarinic blocking drugs

Glycopyrrolate

Homatropine

Methanteline

Propantheline

Methylatropine

Nictotine and synthetic drugs (hexamethonium, pentamethonium, azamethonium, pentolinium)

a parasympatholytic drugs that innhibits the action of parasympathetic nerve by competeing with nicotinic blocking drugs.

Nicotine

This is a parasympatholytic drug that is from the tobacco plant.

Tachycardia leading to heart disease

This is the action of nicotine in cardiovascular system.

Increase peristaltic movement, leading to defecation.

This is the action of nicotine in Gastrointestinal tract.

Relaxation of the bronchus (can’t constrict)

This is the action of nicotine in respiratory system.

Muscle tremors

This is the cause of nicotine in the skeletal muscle.