Pharmocology
Chapter 5

Summary

Autonomic Nervous System- ANS

q       Controls smooth muscle

q       Cardiac muscle

q       Gland secretion

Affects

q       BP,

q       Heart Rate

q       GI Motility

q       Salivary secretions

q       Bronchial smooth muscle

Almost all body tissues are

q       Innervated by ANS

q       ANS = Modified by altering any events associated with

q       Neurotransmitters

q       (synthesis, storage, release, receptor, interaction and deposition)- re-uptake and breakdown

q       Either the receptor or neurotransmitter is effected

IMPORTANT TO DENTAL HYGIENE TREATMENT BECAUSE

q       ANS DRUGS ARE USED IN DENTISTRY

q       Produce adverse oral reactions

q       ( antidepressants and anticholingerics) similar effects to ANS drugs

SANS AND PANS ARE DIVISIONS OF ANS THAT BALANCE EACH OTHER OUT – IF THEY ARE NOT BALANCED THERE IS MEDICATION TO DO SO!!

PANS

PARASYMPATHETIC AUTONOMIC SYSTEM

q       CONSERVATION OF BODY PROCESSES

q       INFLUENCES DIGESTION AND INTESTINAL TRACT MOTILITY

q       PRINCIPLE MEDIATOR = ACETYLCHOLINE

q       NERVES THAT RELEASE ACETYLCHOLINE ARE = CHOLINERGIC

SANS

Sympathetic Autonomic Nervous System

q       Prepares for emergencies, FIGHT OR FLIGHT

q       Transmitters = NOREPINEPHRINE and EPINEPHRINE

q       Nerves that release them are = ADRENERGIC

* NUEROTRANSMITTERS  LOCATION

q       ACETYLCHOLINE= BETWEEN PREGANGLIONIC AND POSTGANGLIONIC NERVES IN PANS AND SANS

q       Norepinephrine = between postganglionic SYNAPSE AND EFFECTOR ORGAN IN SANS

SANS A-RECEPTOR

q       SKIN, SKELETAL MUSCLE

q       VASOCONSTRICTION OF BOTH

q       DRUGS THAT BLOCK ACTION AT A RECEPTOR ARE CALLED  A-ADRENERGIC BLOCKING AGENTS

SANS B-RECEPTOR

B1 AND B2

TYPE OF RECPTOR FOUND IN THE TISSUE DETERMINES THE EFFECT

q       B1 = WHEN EXCITED CAUSE STIMULATION OF HEART MUSCLE = INCREASED HEART RATE AND STRENGTH

q       B2= SMOOTH MUSCLE INHIBITION OR RELAXATION- VASODILATION, BROCHODILATION

q       EX:  ASTHMA MEDS WORK THIS WAY

ANY DRUG THAT BLOCKS B RECEPTORS IS CALLED  B ADRENERGIC BLOCKERS!!

DRUGS

q       ACT WHERE CHOLINE IS RELEASED = CHOLINERGIC

q       ACT WHERE NOREPINEHRINE IS RELEASED ARE = ADRENERGIC

q       ACT WHERE PANS IS LOCATED = PARASYMPATHO-

q       ACT WHERE SANS IS LOCATED = SYMPATHO-

q       ACT AT LOCATION WHERE ANS IS W/ SAME EFFECT = SUFFIX MIMETIC = AGONIST

q       OPPOSITE EFFECT = SUFFIX LYTIC OR BLOCKER

AKA ANTAGONIST

ANS DRUG CATEGORIES

q       P + PARASYMPATHOMIMETIC, CHOLINERGICS

( + = MIMETIC, CHOLINERGICS POSITIVE)

q       P – ANTICHOLINERGICS, PARASYMPATHOLYTICS

( - =  ANTI, NEGATIVE, LYTICS = AGAINST SO ITS NEGATIVE)

q       S + SYMPATHOMIMETIC, ADRENERGIC

( + = MIMETIC POSITIVE)

q       S – SYMPATHOLYTICS, ADRENERGIC BLOCKERS, SYMPATHETIC BLOCKERS

( - = NEGATIVE TO GO AGAINST “LYTIC”, OR TO BLOCK)

facts

q       cholinergics act on site where acetylcholine is released

q       ADRENERGIC ACT AT SITE WHERE EPI OR NOREPI IS RELEASED

q       PREFIXES PARA AND SYMP DENOTE = LOCATION WHERE DRUG ACTS

PANS

CHOLINERGICS AGENTS – PARASYMATHOMIMETIC

q       EFFECTS SIMILAR TO THOSE PRODUCED BY ACETYLCHOLINE

q       DIRECT ACTING DRUGS = DIRECTLY ON SITE = DECREASE HEART RATE

q       INDIRECT ACTING = ACT ON ENZYMES THAT NORMALLY INHIBIT ACETYLVHOLINE

q       EX: ACETYLCHOLINESTERASE, ACETYLCHOLINE IS NOT BROKEN DOWN, PANS IS STIMULATED

q       INCREASE HEART RATE OCCURES

q       RESULTING EFFECT = DEPENDS ON CONCENTRATION OF DRUG

CHOLINERGICS AGENTS USES

q       STIMULATE INTESTINE, BLADDER, POST OP

q       INCREASING PERISTALSIS AND URINATION

q       LOWER OCULAR PRESSURE

q       PROMOTE SALIVATION AND SWEATING

TREAT MYASTHENIA GRAVIS- AUTOIMMUNE DISEASE WHICH IS CHARICTERIZED BY FLUCTUATING SOMETIMES FATAL, MUSCLE WEAKNESS.  EXCESSIVE CHOLINERGIC BLOCKAGE

TREAT IT WITH

q       NEOSTIGMINE, PYRIDOSTIGMINE, AND AMBENONIUM

EFFECTS OF CHOLINERGIC AGENTS TO

CARDIOVASCULAR

q       DIRECT = DECREASE HEART OUT PUT, EFFECTS ON SMOOTH MUSCLE RESULT IN RELAXATION AND VASODILATION, LOWER BP, DECREASE IN PERIPHERAL RESISTANCE

q       INDIRECT – INCREASE IN HEART RATE AND CARDIAC INPUT

Effects of GI

q       Activate smooth muscle

q       Motility and secretion

Ocular

Intraocular pressure is decreased

Adverse reactions of cholinergic agents

q       Extensions of their pharmacologic effects

Slud

q       Salivation

q       Lacrimation

q       Urination

q       Defecation

q       W/ larger doses= paralysis can occur

q       Confusion ( cns)

Contraindications

q       Asthma – bronchial spasm may occur

q       Hyperthyroidism- may cause hypo= atrial fibrillation

q       Gi tract or urinary obstruction, motility

q       Severe cardiac disease

q       Myasthenia gravis being treated by – neostigmine

q       Treatment of Alzheimer’s

Effects of direct acting cholinergic agents specific drugs

q       Pilocarpine ( salagen) treats

Xerostomia

Glaucoma

Occasionally myasthenia gravis

Side effects

q       Sweating , nausea, rhinitis, chills and flushed skin

q       5 mg tabs, tid

q       ophthalmic solutions

pharm. Effects of indirect acting drugs

reversible

Physostigmine (antilirium) treats

q       toxicity- from anticholinergic agents (atropine, phenothiazines, tricyclic antidepressants and antihistamines)

irreversible acting drugs - warfare

parathion

malathion

sarin

Cholinergic crisis

q       excess accho in system, over dosage

q       pralidoxine treats

anticholinergic agents ( parasympatholytic p - )

q       prevents action of – acetylcholine at receptor site,

q       blocked competively by antagonists

q       block the action of acCho on smooth muscle of intestines heart and gland

q       aka muscarinic receptor blockers, do not block the nicotinic receptors

Uses

q       Preop-

q       Inhibit saliva and mucus that are stimulated by gen anes

q       Blocks clowing of the heart rate, general anesthesia

q       Treat GI disorders, to treat diarrhea

q       Dilate eye

q       Reduction of parkinsons

q       Motion sickness dentistry= to create a dry field

SUMMARY ANTICHOLINERGIC AGENTS

CNS

q       Higher doses – stimulate

q       Lower doses – depress

EXOCRINE GLANDS

q       Reduce flow or secretions9 dry field)

Smooth muscle

q       Relaxes smooth muscle in respiratory tract

q       Treatment of asthma

CV

q       Tachycardia- prevent cardiac slowing during general anesthesia( decreases activity of vagus nerve)

Adverse reactions = anticholinergic agents

q       Xerostomia

q       Photophobia- eye

q       Tachycardia

q       Fever

q       Urinary and GI stasis

q       Hot, dry, flushed skin from lack of sweating

TOXICITY

q       Atropine and scapolomine- excitation, hallucinations delirium, and profound CNS depression,  untreated can be fatal

q        

Phenothiazines= antidepressants

Antihistamines = zyrtec, benadryl

Tricylic antidepressants – TCA’s ( older meds)

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