Non Cat Echo La Mines

8/8/2019 Non Cat Echo La Mines

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Non catecholamines

Ephedrine Amphetamine Tyramine

source 1.natural: from ephedra plant.

2.synthetic

1.synthetic 1.natural:in cheese ,

yoghourt , broad

beans, salted fish.

chemistry Non catecholamine alkaloid - stable Non catecholamine - basic Non catecholamine

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absorption Well absorbed orally- delayed onset long duration

distribution Can penetrate BBBfate -Not metabolised by MAO or COMT

(may inhibit MAO)

-part is metabolised in liver and other

pass unchanged in urine.

-acidification of urine ++ absorption.

-Not metabolised by MAO or

COMT

-part is metabolised in liver and

other pass unchanged in urine.

-acidification of urine ++absorp.

metabolised by MAO

(in contrast to all

non Catecholamines)

Routes of

administration

-oral

-S.C

-I.M

-local as eye drops &nasal drops

-oral -oral

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Mechanism of

action

Dual action :

-direct on all R (as adrenaline )

-indirect by stimulate NA release from

adrenergic n. (1- weak 1)

-indirect by stimulate NA

release from adrenergic n. (1-

weak 1)

-indirect by stimulate

NA release from

adrenergic n. (1-

weak 1)

Pharmacological

action

a)local:

1.skin:

-decongestion

-haemostasis

-cause irritation rebound congestion

2.eye:

-decongestion

-IOP(aqueous h. by 1)-active mydriasis except in negroes with

heavily pigmented iris racial tolerance

b)systemic:

1.CVS :

-heart:++ all

-bl.v. :VC in skin & m.m - VD in coronary &

sk.m

-ABP: hypertension when IV it act

only indirect both systolic &

diastolic no change in pulse p.

hypertension is abolished by blocker.tachyphylaxis occur in repeated injection

2.bronchi :

Decongestion & bronchodilatation

3.GIT :

relax wall & contract sphincter

4.urinary bladder :

relax wall & contract sphincter (marked)

5.CNS:

Stimulate cerebral cortex and RAS

wakefulness, alertness ,insomnia

Stimulate RC &VMC (analeptic)

6.skeletal muscle :

VD facilitate NMT in myasthenia g.

7. antiallergic :

8.no metabolic action

1.CVS:

-heart:++ all

-bl.v. :VC in skin & m.m

-ABP: hypertension as it

increase both systolic& diastolic

reflex bradycardia

tachyphylaxis occur in repeated

injection2.eye:

-decongestion

-IOP(aqueous h. by 1)

-active mydriasis

3.skeletal m. as ephedrine

4.antiallergic as ephedrine

5.CNS :

Marked action

1-psychic:

-small dose: euphoria,

wakefulness , alertness ,insomnia-moderate dose: anxiety ,tremor

-large dose: schizophrenia

,convulsions

2-analgesic:

Potentiate morphine action

3-anorexigenic:

feeding center of hypothalamus

acuity of smell and taste

4-analeptic:

Stimulate RC & VMC

5-spinal

Stimulate mono & poly s. reflexes

6-tolerance and addiction occurs

on prolonged use

-Normally it has no

action as it is

metabolised by MAO

enzyme in liver

-in psychic patients

who are treated

with MAO inhibitors

Tyramine will notbe metabolised and

cause release of NA

hypertensive crisis

may be fatal due

to cerebral

hemorrhage

it is treated by

blocker or

combination of ,

blockers.

-interaction bet.Tyramine and MAO

inhibitors us called

cheese interaction

(one of the drug

food interaction )


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Therapeutic uses 1.nasal decongestant it cause rebound

congestion so pseudoephedrine is better

2.mydriatics in fundus examination

3.hypotension in spinal anaesthesia or

overdose of GB or sympathectomy

4. AV block

5.prophylaxis of bronchial asthma (SABA

is better)

6.nocturnal enuresis (TCAS are better)

7.nacrolepsy (amphetamine is better)8.adjuvant to neostigmine in myasthenia

(Not commonly used nowadays)

1.nacrolepsy

2.attention deficient

hyperkinetic disorders (ADHD)

3.psychic depression in

parkinsonism and chronic

alcoholics to elevate mood

4.obesity

5.ttt of acute toxicity in drugs

that inhibit RC as morphine5.nocturnal enuresis

Adverse effect -tachycardia

-palpitation

-anginal pain

-hypertension

-urine retention especially in prostatic

hyperplasia

-CNS stimulation (insomnia)

-tolerance (no addiction)

-hypertension

-reflex bradycardia

-insomnia

-anorexia & weight loss

-tolerance & addiction

-Acute toxicity:

1)Manifestation:

Hypertension-bradycardia-

active mydriasis-insomnia-hallucination then convulsion

then coma and death

2)treatment:

-Stomach wash

-artificial respiration

-no specific antidote -

symptomatic treatment

- urinary acidity to excretion

contraindications -As adrenaline

-prostatic hyperplasia

-hypertension

-bradycardia

-psychic disorders asschizophrenia

-MAO inhibitors as they cause

hypertensive crisis treated

by blocker or combination of

, blocker


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N.B :

1) Vasopressor sympathomimetics :

-include : phenylephrine methoxamine midodrine

-actions: 1)VC decongestion, haemostasis & prolong action of LA , hypertension and reflex bradycardia

2)Active mydriasis

-therapeutic uses:

1)phenylephrine & methoxamine: decongestion - haemostasis action of LA hypotension _ PAT fundus examination

2)midodrine : prodrug converted to active metabolite in treatment of chronic postural (orthostatic) hypotension

2) Nasal decongestants :

a)local: naphazoline tetrahydrazoline oxymetazoline xylometazoline used in common cold. Sinusitis, rhinitis

but they cause drowziness in children and may cause atrophy of olfactory mucosa and ansomnia in long term use.

b) systemic(oral): pseudoephedrine phenylpropnolamine ( not used as it cause hemorrhagic strokes)

3) non selective agonists :

Includes adrenaline isoprenaline isoxsuprine (used in PVD and contraction ring of uterus)

4) selective 1 agonists :

Includes : dobutamine Prenalterol ( given orally or IV and is used in treatment of heart failure

5) selective 2 agonists :

Includes :

1- isoetharine : catecholamine metabolized by COMT

2- salbutamol terbutaline : non catecholamine , short acting selective 2 agonist = SABA

in treatment of acute attacks of bronchial asthma

3- salmeterol formeterol bambuterol : non catecholamine , long acting selective 2 agonist = LABA in prophylaxis of bronchial asthma

4- ritodrine : non catecholamine used in uterine relaxation (tocolytic) in contraction ring of the uterus , premature

labor, threatened abortion , dysmenorrhea

Pharmacological action :

-VD in skeletal muscle ABP

-bronchodilatation and mast cell stabilization and inhibition of release leukotrienes

-uterine relaxation

-tachycardia (reflex or direct if it is given in large doses as selectivity is not absolute )

-tremors

Therapeutic uses :

-bronchial asthma

- contraction ring of the uterus , premature labor, threatened abortion , dysmenorrhea

Adverse effects :

-tachycardia

-hypotension , flushing

-tremors

-hypokalemia

-tolerance due to down regulation of receptors ( prevented by cortisone)


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