Autonomic nervous system - pharmacology

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Transcript of Autonomic nervous system - pharmacology

AUTONOMIC DRUGS

Autonomic Nervous System(Visceral Efferent Nervous SYSTEM)

Involuntary Efferent( motor fibers) Preganglionic and Postganglionic neurons Effectors: smooth muscles, cardiac muscle,

gland

Autonomic Nervous System

CNS Sympathetic } smooth muscle preganlionic postganglionic effector } cardiac muscle

●---------------- ●---------------------- Ο ↓ ↓ acetylcholine norepinephrine

adrenal preganglionic gland ●------------------------ Ο → epinephrine ↓ acetylcholine

Parasympathetic preganglionic postganglionic effector ●-------------------- ●---------------------- Ο ↓ ↓ acetylcholine acetylcholione

Divisions

a. Sympathetic (Thoracolumbar )-

* 1st thoracic vertebrae extending through the 2nd and 3rd

lumbar

* fight and flight division

* Epinephrine and Nor epinephrine

b. Parasympathetic (Cranio-Sacral)

* Nuclei of the 3rd, 7th, and 10th cranial

nerve and 1 to the 4th sacral spinal

segments

* acetycholine

Pharmacology of the parasympathetic division

Pharmacology of the Parasympathetic Division

I. Cholinergic agonist (Parasympathomimetic)

a. Choline esters: acetylcholine chloride methacholine chloride

bethanecol chloride

carbachol chloride

b. Alkaloids: Muscarine,

Pilocarpine- miotic in glaucoma

increase salivation

II. Cholinesterase inhibitorsa. Slowly reversible neostigmine ( drug of choice for myasthenia gravis)

physostigmine b. Rapidly reversible: Edrophonuim

c. Non Reversible: chemical warfare and insecticides

III. Cholinergic blocking drugs (parasympathomimetic) a. Naturally occurring alkaloids: 1. Atropine * Atropine sulfate, 0.5-1mg 1-2 hours before dental procedure

* antisialogogue * mydriasis, antispasmodic, decrease gastric and

salivary flow 2. Scopolamine

* Scopolamine Hydrobromide, 0.3- 0.6mg* pre-anesthetic

b. Synthetic anticholonergic

* propantheline bromide (Pro-Banthine)

* aid in ulcer therapy

Side effects: blurred vision, tachycardia sweating and

dry skin

Pharmacology of the Sympathetic Division

I. Adrenergic Agonist (Sympathomimetic)

a. Epinephrine hydrochloride

( adrenaline)• Cardiac stimulant• Alpha and beta stimulating ( vessels of skin,

mucous membrane, kidney- vasoconstriction• Smooth muscles of the bronchi- vasodilation

* topical solution (1:1000) –gingival retraction, hemostatic agent

* drug of choice for acute anaphylaxis

and asthmatic attack

(0.2-0.5 ml: 1:100,000 aqueous solution)

* Vasoconstrictor in local anesthesia

(1: 50, 000, 1:100, 000)

* Used in caution: elderly, CV disease,

hypertension, hyperthyroidism

b. Nor epinehrine

* alpha stimulating

* hypotension in shock

c. Isoproterenol ( Isuprel)

* beta stimulating

* cardiac stimulant

* primary used in the treatment of

asthma and heart problem

d. Dopamine

* alpha and beta

* shock associated with sepsis and myocardial etiology

e. Ephedrine

* alpha and beta

* intranasal solution for localized decongestive effect

Synthetic adrenergic drugs

Phenylephrine- nasal decongestant Terbutaline- bronchodilator Dextroamphetamine sulfate- narcolepsy,

attention deficient disorder

Adrenergic Blocking drugs(sympatholytic)

a. Alpha blockers

prazosin (Minipress)

b. Beta blockers

1. selective B1 (cardioselective

i. acetabutalol ( Sectral)

ii. Atenolol ( Tenormin)

iii. Metroprolol (Lopressor)

2. non selective

i. propranolol (Inderal)

ii. timolol ( Blocadren)

iii pindolol ( Visken)

C. Neuronal blocker

D. Ganglionic blocker

CNS STIMULANTS

Heterogeneous group of compound that produce various degree of stimulation depending on the compound, the dose and occasion and use

Classification

I. Analeptics and Respiratory stimulants

a. Pentelynetetrazol (Metrazol)

b. Nikethamide( Coramine)

c. Doxapram (Dopram)

d. Picrotoxin

e. Strychine

II. Xanthine Bases

(Caffeine, theophylline and theobromine)

pharmacologic effects:

CNS and Respiratory stimulants

diuretics

cardiac stimulants

bronchodilator

A. Caffeine

□ most widely ingested CNS stimulants

□ insomia, nervousness, palpitation

tachycardia

□ Increase gastric secretion

□ habituation

B. theophylline

+ ethylne diamide= aminophylline

severe cases of asthma

C. theobromine

III. Sympathomimetic amide

A. Amphetamine and related drugs)

□ Wakefulness, alertness,

decrease fatigue

□ Increase ability to concentrate

□ Euphoric effect

□ Mood will be elevated

Headache Hallucination Dysphoria Anorexia Psychotic episode

B. Cocaine – local anesthetic

Drugs

I. hemostatics/ antihemorragic

II. Antibiotic

III. Antihistmine

IV. Analgesic, Antipyretic

Antiinflammatory

V. Anesthetics

VI . Minor tranquilizer, sedative-hypnotic

sedative antihistamine

Bleeding

infection

Allergy

Pain, Fever Inflammation

Pain

Anxiety/fear