LESSON 8: Drugs used in the Autonomic Nervous System Flashcards
-Has only one neuron
-No ganglion
-Voluntary, controllable
-thicker myelin sheath/heavily myelinated axon
Somatic Nervous System
Neurotransmitter of Somatic Nervous System
Acetylcholine
-Has two neurons
-Presence of ganglion (exclusive in ANS)
- Involuntary, uncontrollable
-Has a thin myelin sheath
Autonomic Nervous System
Autonomic Nervous System Neurotransmitter
Norepinephrine for Sympathetic
(Noradrenaline) and Acetylcholine for
Parasympathetic
Efferent organs (EO): Somatic Nervous System
Skeletal muscles
Efferent organs (EO): Autonomic Nervous System
Smooth muscles (such as the urinary bladder, GI
tract), cardiac muscles and exocrine glands
“Fight or Flight”
Sympathetic
Origin of neurons of Sympathetic
Thoracolumbar region
Dilation of pupils (Mydriasis)
Sympathetic “Fight or Flight”
Widening of mouth + Decreased salivatio
Sympathetic “Fight or Flight”
Decreased GIT activity (loss of peristalsis,
decreased bowel movement, constipation)
Sympathetic “Fight or Flight”
Increased heartbeat/contraction - tachycardia
Sympathetic “Fight or Flight”
Bronchodilation (dilate lungs to easily distribute
oxygen in body, compensation for adrenaline
rush)
Sympathetic “Fight or Flight”
Increased muscle tone (to regain strength)
Sympathetic “Fight or Flight”
Bladder relaxation → urinary retention
Sympathetic “Fight or Flight”
Piloerection (regulate body temperature,
especially if scared need iconserve heat)
Sympathetic “Fight or Flight”
Penis ejaculation
Sympathetic “Fight or Flight”
“Rest and Digest”
Parasympathetic
“Rest and Digest
Parasympathetic
Origin of neurons: Parasympathetic
Craniosacral region
Constriction of Pupils (Miosis)
Parasympathetic “Rest and Digest
Increased salivation
Parasympathetic “Rest and Digest
Increased GIT activity (increased
peristalsis/secretion/metabolis, increased bowel
movement, diarrhea)
Parasympathetic “Rest and Digest
Decreased heartbeat - bradycardia
Parasympathetic “Rest and Digest
Bronchoconstriction
Parasympathetic “Rest and Digest
Bladder contraction → urination
Parasympathetic “Rest and Digest
Penis erection
Parasympathetic “Rest and Digest
Also called as “Intrinsic Nervous System”
ENTERIC NERVOUS SYSTEM
Consists of the submucosal, myenteric, and subserosal plexuses
ENTERIC NERVOUS SYSTEM
Consists of a mesh-like system of neurons that governs
the function of GI tract
ENTERIC NERVOUS SYSTEM
Regulates the movement of water as well as electrolytes between the gapped lumen (?) and tissue compartments
ENTERIC NERVOUS SYSTEM
- inhibit choline transporters
(anticholinergic)
Hemicholinium
- inhibit vesicle-associated transporter or
VAT (anti-parasympathetic effect)
Vesamicol
inhibit docking proteins (VAMPs
and SNAPs)
Botulinum toxin
found in the synaptic
cleft, inhibits the acetylcholinesterase (increases
effect of acetylcholine to bind in post-synapse)
Anti-acetylcholinesterase
inhibit tyrosine hydroxylase
(anti-sympathetic effect)
Metyrosine
inhibits vesicular monoamine
transporter (VMAT)
Reserpine
- inhibit docking
proteins (VAMPs and SNAPs, exocytosis inhibitors)
Bretylium, guanethidine, guanidyl -
- inhibit norepinephrine transporter (NET), acts as a reuptake inhibitor (reabsorption or recycling)
Cocaine, tricyclic antidepressants (TCA)
SYMPATHOMIMETICS Pressor Agents
● Noradrenaline (Norepinephrine)
● Ephedrine
● Dopamine
● Phenylephrine
● Methoxamine
● Mephentermine
SYMPATHOMIMETICS Bronchodilators
● Isoprenaline
● Salbutamol (Albuterol)
● Terbutaline
● Salmeterol
● Formoterol
● Bambuterol
SYMPATHOMIMETICS CNS Stimulants
● Amphetamine
● Dexamphetamine
● Methamphetamine
● Methylphenidate
SYMPATHOMIMETICS Uterine Relaxants
● Ritodrine
● Isoxsuprine
● Salbutamol
● Terbutaline
SYMPATHOMIMETICS Cardiac Stimulants
● Adrenaline
● Isoprenaline
● Dobutamine
SYMPATHOMIMETICS Nasal Decongestants
● Xylometazoline
● Oxymetazoline
● Naphazoline
● Phenylephrine
● Phenylpropanolamine
● Pseudoephedrine
SYMPATHOMIMETICS Anorectics
● Amphetamine
● Fenfluramine
● Dexfenfluramine
● Sibutramine
α-ADRENERGIC BLOCKING DRUGS ( NON-EQUILIBRIUM TYPE
β-haloalkylamine (Phenoxybenzamine)
α-ADRENERGIC BLOCKING DRUGS : EQUILIBRIUM TYPE (Competitive Antagonists) : α1 Selective
● Prazosin
● Terazosin
● Doxazosin
● Alfuzosin
● Tamsulosin
α-ADRENERGIC BLOCKING DRUGS : EQUILIBRIUM TYPE (Competitive Antagonists) : α2 Selective
Yohimbine
Non-Selective EQUILIBRIUM TYPE (Competitive Antagonists)
Ergot alkaloids, Hydrogenated
ergot alkaloids, Imidazoline, Miscellaneous
NON-EQUILIBRIUM TYPE (β1 + β2 (β-ADRENERGIC BLOCKING DRUGS)
Without ISA :
● Propranolol
● Sotalol
● Timolol
With ISA:
● Pindolol
With α blocking
property:
● Labetalol
● Carvedilol
B. CARDIOSELECTIVE (β1) (
β-ADRENERGIC BLOCKING DRUGS)
● Metoprolol
● Atenolol
● Acebutolol
● Bisoprolol
● Esmolol
● Betaxolol
● Celiprolol
● Nebivolo
First Generation β-ADRENERGIC BLOCKING DRUG
● Propranolol
● Timolol
● Sotalol
● Pindolol
Second Generation β-ADRENERGIC BLOCKING DRUG
● Metoprolol
● Atenolol
● Acebutolol
● Bisoprolol
● Esmolol
Third Generation
With α
Third Generation β-ADRENERGIC BLOCKING DRUG
● Labetalol
● Carvedilol
● Celiprolol
● Nebivolol
● Betaxolol
CHOLINERGIC DRUGS (CHOLINERGIC AGONISTS)
Choline esters:
● Acetylcholine
● Methacholine
● Carbachol
● Bethanechol
Alkaloids:
● Muscarine
● Pilocarpine
● Arecoline
CHOLINERGIC DRUGS (ANTICHOLINESTERASES; REVERSIBLE)
Carbamates:
● Physostigmine (Eserine)
● Neostigmine
● Pyridostigmine
● Edrophonium
● Rivastigmine
● Donepezil
● Galantamine
Acridine:
Tacrine
CHOLINERGIC DRUGS (ANTICHOLINESTERASES; IRREVERSIBLE)
Carbamates:
● Carbaryl (Sevin)
● Propoxur (Baygon)
Organophosphates:
● Dyflos (DFP)
● Echothiophate
● Malathion (insecticide)
● Diazinon* (TIK-20)
● Tabun (nerve gases for chemical
warfare)
● Sarin (nerve gases for chemical
warfare)
● Soman (nerve gases for
chemical warfare)
IS ATROPINE ANTIMUSCARINIC OR MUSCARINIC?
ANTIMUSCARINIC AGENTS (ANTAGONISTS)
ATROPINE Causes _____________________
blockade of cholinomimetic (mimics
action of cholinergic or
parasympathetic) actions at
muscarinic receptors
reversible (surmountable)
When atropine binds to the
muscarinic receptor, it prevents
actions such as the release of_____________ and the inhibition
of adenylyl cyclase that are caused
by muscarinic agonists
inositol
trisphosphate (IP3)
Therapeutic uses of atropin
Mydriatic, cycloplegic, Antispasmodic, Antidote for cholinergic agonist, Antisecretory agent
dilation of the pupil
of the eye caused by contraction
of the dilator muscle of the iris,
decrease in light, action of drug
Mydriasis
paralysis of the
ciliary muscles of the eye that
results in the loss of visual
accommodation
Cycloplegia
Scientific name of Atropine
Atropa belladonna
Natural sources of atropine
● Atropine (isomer Hyoscyamine)
● Found in Solanaceae family
○ Datura stramonium (Jamestown
weed, sacred datura, thorn apple)
○ Hyoscyamus niger (henbane)
○ Mandragora officinarum
(mandrake)
Muscarinic organs
nerve, heart and smooth muscles,
glands and endothelium
Nicotinic organs
- neuromuscular endplate, skeletal muscles,
autonomic ganglion cells
Cholinoreceptor stimulants: Direct acting
■ Alkaloids - nicotine, pilocarpine, obeline
■ Choline esters - methacholine, carbachol,
bethanechol
Cholinoreceptor stimulants: Indirect acting
■ Reversible - carbamates (neostigmine,
physostigmine), edrophonium
■ Irreversible - organophosphates (malathion,
parathion)
reverses action of
non-depolarizing neuromuscular blockers
Neostigmine
anti-alzheimer’s
Physostigmine & Edrophonium:
PILOCARPINE IS MUSCARINIC OR ANTIMUSCARINIC?
MUSCARINIC
Pilocarpine is the drug of choice for
emergency
lowering of intraocular pressure of
both narrow angle (closed-angle)
and wide-angle (open-angle)
glaucoma
Pilocarpine is contraindicated for
asthma, peptic ulcer, coronary
artery diseases
Natural Sources of pilocarpine
● Rutaceae family, genus Pilocarpus,
(common name Jaborandi)
● Pilocarpus pennatifolius (South
American
