Autonomic Pharmacology Flashcards
resistant to orally administered atropine, but
may be responsive to parenteral administration
horses and cattle
sensitive to either oral or parenteral atropine
Pigs, dogs and cats
especially resistant to the effects to atropine because of the presence of a high concentration of atropinase
goats and rabbits
should not be given to animals
poisoned with OP
Phenothiazine tranquilizers and opiates
clinically useful only during the early stages of
poisoning
Pralidoxime (2-PAM)
atropine is an antidote of OP which blocks muscarinic effects but not to
nicotinic effects
most important antidote to the effects of OP
atropine
Some deadly gases of Ops (2)
Diisopropyl fluorophosphate (DFP), Triorthocresyl phosphate (TOCP)
irreversible cholinesterase inhibitors
organophosphates
hyperglycemia and hyperlipidemia
catecholamines
prevent their rapid absorption, to prolong the local action, and to decrease the systematic of local anesthetic
vasocontrictors (such as epinephrine)
glycogen phosphorylase
converts glycogen back to glucose
2% of the total serotonin in the mammalian body is located within the CNS, especially in
pineal gland and hypothalamus
serotonin is chemically known as
5- hydroxytryptamine (5-HT)
enterochromaffin cells of the intestine contain % of serotonin
90%
hyperglycemia is caused by inhibition of
glucose synthase (uses glucose to make glycogen)
drug of choice to relieve the symptoms of an acute hypersensitivity reaction to allergens.
Epinephrine
rapidly relieves itching and
urticaria and may save the life of the patient when laryngeal edema threatens suffocation
subcutaneous administration (of epinephrine)
Beta adrenergic blockers include:
- Dichloroisoproterenol
- Propanolol
- Timolol
- Alprenolol
- Pindolol
- Nadolol
- Sotalol
- Atenolol
- Metoprolol
- Butoxamine
responsive to antihistamines, but epinephrine is
necessary in the event of a severe reaction
angioedema
adrenal medulla as a modified sympathetic ganglion responds to
acetylcholine
adrenal medulla secretes epinephrine in response to administration of
nicotine
Clinical uses of beta adrenergic blockers
- Hypertension in humans
- Reversing digitals-induced arrhythmia
- Treatment of obstructive cardiomyopathy, a rare disease on dogs and cats
- Block the effect of excessive epinephrine in pheochromocytoma
Clinical uses of alpha adrenergic blockers
- Cardiovascular shock
2.Overcome the effect of excessive epinephrine in Pheochromocytoma
Alpha adrenergic blockers
- Ergot alkaloids (ergonovine)
- Phenothiazine and butyrophenone tranquilizers
- Tolazoline, Atipamezole and Yohimbine
- Prazosin
Clinical uses of sympathomimetics/ adrenergic
- Adjunct to local anesthesia
- Hemostatic - epistaxis in horses
- Mydriatic – gross dilatation of the pupil
- Anaphylactic reactions
- Bronchodilator – expansion of the lumina of the passages of the lungs
- Local skin allergy
- Decongestant
- Cardiac arrest
- Hypertensive conditions
Mixed acting adrenergic drugs include:
- Amphetamine
- Methamphetamine
- Ephedrine
- Pseudoephedrine ( D-isoephedrine )
- Hydroxyamphetamine
Muscarinic signs
a. colic
b. diarrhea
c. dyspnea
d. hypotension
e. miosis
f. excessive secretion
nicotinic signs
a. muscle tremors then paralysis
b. convulsions
c. mania then coma
Xylazine, medetomidine
α2 stimulants
a1
present in postsynaptic fibers
a2
present in both pre and post synaptic fibers
dopamine
β1 stimulant
Components of nasal decongestants or ophthalmic vasoconstrictors
- Naphazoline
- Tetrahydrozoline
- Phenylpropanolamine
beta adrenergic chiefly in heart
B1
beta adrenergic present in blood vessels and bronchi
b2
Classification of adrenergic receptors
- alpha adrenergic
- beta adrenergic
- dopaminergic
Epinephrine (adrenaline) stimulates
both alpha and beta receptors
Anticholinergics
atropine, scolopamine, glycopyrrolate
Norepinephrine (noradrenaline) is mainly an stimulant of
alpha receptors
phenylephrine
alpha stimulant
isoproterenol
beta stimulant
poisonous substance in certain species of mushrooms
muscarine
substance derived from tobacco
nicotine
Classification of cholinergic receptors
- Muscarinic effect
- Nicotinic effects
Ach is not used in clinical therapeutics because of the following reasons
- Following its administration, it causes too generalized but transient effect.
- It is so readily hydrolyzed by plasma cholinesterase that it cannot be
detected in the plasma following absorption
Sympathetic tone maintains
systemic blood pressure
Parasympathetic tone maintains
gut motility
the major neutransmitter at the postganglionic fibers in the sympathetic division
norepinephrine
postganlionic fibers are called
adrenergic fibers
transmitter released at the peripheral motor portions of the autonomic nervous system
acetylcholine
predominance of one division over the other is called
state of tomus
Transmitter of effectors of sympathetic
norepinephrine
Ganglionic synapse of parasympathetic
discrete
Conservation of energy
parasympathetic
Massive discharge of energy
sympathetic
Anticholinergics are also called
parasympatholytics
ganglionic mediator of both parasympathetic and
sympathetic nerves
acetylcholine
name 2 amines which derived its name from enterochromaffin cells
serotonin and enteramine
hexamethonium
ganglion blockers
a. Tubocurarine
b. gallamine
c. pancuronium
d. succinylcholine
neuromuscular blockers
hemicholinium
Acetylcholine synthesis inhibitor
a. Botulinus toxin
b. aminoglycoside
antibiotic
acetylcholine release inhibitor
Indirect acting cholinergic (cholinesterase inhibitors)
a. Physostigmine
b. Neostigmine
c. edrophonium
d. pyridostigmine
e. organophosphates
f. carbamates (carbaryl, propoxur)
Cholinergic drugs are also called
parasympathomimetics or cholinomimetics
Directly acting cholinergic
- methacholine
- carbachol
- bethanechol
- muscarine
- pilocarpine
- arecoline
include the action of acetylchloline of the parasympathetic and sympathetic ganglia
nicotinic effects
Parasympathetic =
cholinergic
Sympathetic =
adrenergic
