pediatric cough cme

8/14/2019 Pediatric Cough CME

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Role of cough syrups and anti-pyretics in treatment of pediatric

cough: Children are not miniature

adults


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Cough is a very elaborate act with the explicitintention of expelling irritants in the

respiratory tract

The irritants may be intrinsic eg. Mucus & phlegm

or extrinsic eg. Foreign particle or body

Cough is reflex-evoked modification of breathing pattern in

response to airway irritation

Cough can also be produced voluntarily

Why do we cough?


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How do we cough?

The event of cough is deep inspiration followed by forceful expulsion

Diaphragm and external intercostal muscles contract, creating a negative

pressure around the lung.Air rushes into the lungs

The glottis closes and the vocal cords contract to shut the larynx.

The abdominal muscles contract to accentuate the action of the relaxing

diaphragm; simultaneously, the other expiratory muscles contractincrease the pressure of air within the lungs upto 300mmHg.

The vocal cords relax &the glottis opensreleasing air at over 100mph.

The bronchi and non-cartilaginous portions of the trachea collapse to

form slits through which the air is forced, which clears out any irritantsattached to the respiratory lining.

However mechanical laryngeal stimulation as in aspiration results in

immediate expiratory stimulation without the preceding inspiratory

phase to protect the airway from aspiration by expiratory reflex.


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How do we cough?

Each cough occurs through the stimulation of acomplex reflex arc constituted by:

Afferent pathway: Sensory nerve fibers located in theciliated epithelium of the upper airways, branchesfrom the diaphragm. The afferent impulses go to themedulla diffusely.

Central Pathway : a central coordinating region forcoughing is located in the upper brain stem and pons.

Efferent pathway: Impulses from the cough centertravel via the vagus, phrenic, and spinal motor nervesto diaphragm, abdominal wall and intercostal muscles.


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How do we cough?

This is initiated by the stimulation of

cough receptors which are found in the

trachea, main carina, branching points of

large airways, and more distal smaller

airways, the pharynx, external auditory

canals, eardrums, paranasal sinuses,

pharynx, diaphragm, pleura, pericardium,

and stomach.

The receptors are mechano-recptors

stimulated by irritation by mucus plug,

foreign body, particulate matter etc or

chemorecptors stimulated by irritants,

fumes, aspirates,The afferent neural pathway is through the

internal Laryngeal branch of the Superior

Laryngeal branch of the Vagus.

The efferent neural pathway is mediated

through the Vagus, Phrenic nerve & theIntercostal nerves


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NOT SMALL ADULTS(CAUTION WITH EXTRAPOLATING ADULT LITERATURE)

Viruses responsible for common cold in adults may cause seriousrespiratory illness in kids.

Maturational differences in airway anatomy, respiratory

musculature, chest wall structure. Differences in medication response.

Medical history in young kids is limited by parental perception andavailability.

Children should be managed according to the studies and guidelines forchildren (when available), because etiologic factors and treatments inchildren are sometimes different from those in adults.


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DIAGNOSTIC APPROACHES

Children with chronic cough require careful and systematicevaluation for the presence of specific diagnostic indicators.

In children with chronic cough, the etiology should be defined andtreatment should be etiologically based.

Children with chronic productive purulent cough should always beinvestigated to document the presence or absence of bronchiectasisand to identify underlying and treatable causes such as cystic fibrosisand immune deficiency.

History and physical exam first:

Specific pointerssuggestive of specific cough.


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Pointers to the Presence of Specific Cough

Auscultatory findings, wheeze, crepitations

Cardiac abnormalities

Chest pain

Chest wall deformity

Digital clubbing, FTT (CF)

Neurodevelopmental (potential for aspiration)

In children with nonspecific cough, cough may spontaneously

resolve, but children should be reevaluated for the emergence

of specific etiologic pointers.


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12yo male with remote history of URI has been coughing since

Thanksgiving.

Children with chronic cough should undergo, as a minimum, CXR and

spirometry, if age appropriate.

CXR quick, readily attainable.

Spirometry reliably performed in kids > 6 yrs (often >3 yrs, with

appropriate personnel).


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Also considered: Chest or sinus CT

a.) HRCT as current gold standard for eval of small airwayanatomy.

b.) Lifetime cancer risk is age and dose dependent.c.) Single Chest CT scan ~ 5.8 mSv (CXR ~ 0.02 mSv, so =300 CXRs).

Flexible bronchoscopy

1.) suspicion of airway abnormality.2.) localized radiology changes.3.) suspicion of inhaled foreign body.4.) eval of aspiration lung disease.

5.) micro studies and lavage (BAL).


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ETIOLOGY

In children with specific cough, further investigations may be

warranted, except when asthma is the etiologic factor.

Cough is the most common presenting symptom in patients

presenting to doctors in US and Australia.

Viral URIs, which also cause cough, are said to account for 80

percentof childhood asthma exacerbations.

7yo female with known RAD presents withcough and wheezing.


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ETIOLOGY

Upper Airway Disorders and Cough

Upper airway cough syndrome (aka post-nasal drip) well

documented in adults.

In children, relationship between nasal secretions and cough ismore likely linked by common etiology (infection or

inflammation).

Abnormal sinus radiographs found in 18-82% of

asymptomatic children.

No RCTs on therapies for upper airway disorders in kids with

improvement of nonspecific cough as outcome measurement.


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ETIOLOGY

GERD and Cough

PROOF that GERD causes chronic cough in kids is rare.

Infants often regurgitate, but few well infants cough with these

episodes. Available prospective studies of chronic cough in kids suggest

that GERD is infrequently the SOLE cause.


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ETIOLOGY

Airway Lesions and Cough

Prevalence of airway lesions found in asymptomatic children

is unknown.

Relationship of cough to airway lesion can only be postulated: Airway malacia impedes clearance of secretions; potential for

pneumonic process distal to lesion


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ETIOLOGY

Environmental Pulmonary Toxicants

Increases susceptibility to respiratory infections

Increases coughing illnesses

Close association to tobacco smoke exposure, especially inassociation with asthma.

15yo female with cough for past month, noticed by parents

that only occurs after home from school.

In all children with cough, exacerbating factors such as ETS exposure

should be determined and interventional options for the cessation of

exposure advised and initiated.


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ETIOLOGY

Chronic Nocturnal Cough

Unreliability and inconsistency of reporting.

Often used as a direct indicator of asthma.

Community based study revealed only a third of children withisolated nocturnal cough had asthma.

No studies that objectively document that nocturnal cough is

worse than daytime cough in uncontrolled asthmatics.


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ETIOLOGY

Respiratory Infections and Postinfectious Cough

Postviral cough refers to presence of cough after acute viral

URI. Unstudied natural history beyond 25 days.

Re-infection (when not completely recovered) may result inappearance of prolonged coughing.

Total respiratory illnesses per person year ranges 5-8/yr

(


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ETIOLOGY

Psychogenic Cough

AKA habit cough, tic cough, psychogenic cough.

Behaviorial association.

Inhalation of Foreign Body

Presentations usually acute, but chronic cough may be

presenting symptom of missedFB inhalation.

Normal CXR does not exclude. Specific history should be sought.


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ETIOLOGY

Parental Expectations

Parental expectations as well as the doctors perceptions (of said

expectations) influences consulting rates and prescription use.

Use of OTC meds and frequency of doctors visits were less

likely with more highly educated mothers.

Parental concerns can be extreme and include fear of child

choking and dying, SIDS, asthma attack, permanent chest

damage.

In children with nonspecific cough, parental expectations should be

determined, and the specific concerns of the parents should be sought and

addressed.


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Types of coughs

Dry or non productive cough

Phlegmy or productive cough

Croupy or barking cough Cough with wheezing

Pertussis or cough with a whoop

GERD or cough with choking


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Dry or nonproductive coughShort bursts of incessant cough

Occurs daytime as well as nighttime

Associated with hoarseness of voice, pain while swallowing and

on external pressure

Nocturnal dry cough is aggravated in supine position due to post

nasal dripAcute dry cough is caused by upper respiratory infections due to

virus including Flu virus, bacterial infections including

Streptococcus, H Influenzae and Chlamydia

Chronic dry cough could be due to enlarged tonsils, adenoidswith post nasal drip or intraluminal or extraluminal obstruction in

upper airway eg. Endobronchial/ paratracheal LNs

Pharyngeal irritation directly is unlikely to induce cough because the innervation is

Glossophayngeal & not vagus.


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Phlegmy or Productive cough

Productive cough is due to catarrh due excessive

production or non clearance of mucus from upper/ lowerairway

It could be infective or noninfective

Infective productive cough could be due to infection in

upper airway as in paranasal sinusitis or lower airway as in

pneumonia or bronchiectasis

Non infective productive cough could be due to allergic

catarrh or due to thick tenacious phlegm as in cysticfibrosis

Cough is seen daytime as well as night time


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Croup or barking cough

Sudden onset spasmodic non productive cough with a barkingquality

Mostly occurs in early half of night

Mostly occurs in children below 3 years of age

Generally preceded by mild corryza with/ without fever of shortduration

Although dramatic in onset & presentation, child doesnt appear

toxic or in pain or distress. No dysphagia.

Very few children have recurrences till age of 3 years.X-ray neck AP view shows subglottic narrowing of airway:

Steeple sign

Toxic child with dysphagia, dysphonia should have X-ray neck

Lateral view to r/o epiglottitis which is a medical emergency.


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Pertussis or cough with a whoop

Prolonged cough with short outbursts of cough ending

with asound of whoop

Lasts from a few weeks to months even after specific

treatment with appropriate antibiotics.

Severity of cough esp in small infants can lead toconjunctival , oral mucosal bleed, intracranial bleed

can lead to convulsions or loss of cosciousness.

A bout of cough may lead to severe vomiting as wellas poor intake of food, leading to malnutrition

GERD h ith h ki


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GERD or cough with choking

Coughing associated with feeding events

More common in supine feeding- more in bottle-fed than breast fed

infants.Occurs in neonates and may continue till late infancy when child starts

to feed in sitting position esp semisolid & solid feeds

Typically starts within few minutes of feeding with mild clearing throat

sounds leading to head bobbing followed by bout of vomiting or coughas mouth fills with milk rising from the esophagus. Head bobbing may

even lead to retraction of neck .

Severity of GERD is classified in terms of frequency as well as degree of

reflux.It occurs due to physiological laxity of lower esophageal sphincter with

acidic stomach contents coming into esophagus

The cough is due to stimulation of chemoreceptors in the distal airway & Vagal

innervated receptors in the esophagus


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Why should we treat cough?

It is obvious that the process of cough is beneficial andhelps to clear mechanical or chemical irritants in the

respiratory tract.

However the large pressures & velocities generated in the

airways are also responsible for many of the complicationsof cough, including hoarseness, excessive perspiration,

urinary incontinence, rib fractures, musculoskeletal pain,

exhaustion, headache, dizziness & self-consciousness.

The nocturnal cough with/ without post nasal drip leaves the

child insomnic with daytime somnolescence & hyperkinetic

behavior.


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Choice of cough medications

The purpose of cough medications is alleviation of

symptoms.They are always add-ons to specific medications such as

Antibiotics, Bronchodilators, antiallergics eg

antihistaminic & interleukin receptors inhibitors egMontleukast or anti-inflammatory eg steroids

Cough medications are given as cough suppressants,

decongestants, expectorants & mucolytics.

They are available as tablets, syrups or lozenges


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Cough suppressants

Cough suppressants prevent or stop coughing

Cough suppressants cross the blood brain barrier &

act on the center in the medulla that controls the

cough reflex i.e. they act centrally

They are narcotic derived e.g. Codein, pholcodein,Noscapine and non addictive narcotic like

Dextromethorphan or non narcotic like Benzonatate

They are useful to suppress dry cough, nocturnalcough and pertussis.

They are prone to be abused

They are not safe below 6 years of age.


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Cough suppressants Dextromethorphan is the commonest cough suppressant

available either alone or in combination with antihistamines ordecongestants

Derived from morphine, it is a narcotic antitussive but has noanalgesic or addictive property

Although it is as effective as Codein as an antitussive inadults, its efficacy is no better than placebo

Although it is non addictive in therapeutic dose , in very highdose it is used for recreation and is prone to be abused.

Dosage: 0.5 mg/kg/dose 3-4 times a day Codein: Centrally acting narcotic antitussive available either

alone or in combination with antihistmines.

Dosage: 0.3mg/kg/dose 2-3 times/day

Noscapine: Non addictive narcotic antitussive.


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Mucokinetic agentsThese are various agents which help to keep the mucus

thin and helps the mucociliary mechanism to expelthe thick mucus.Act on the afferent wing of cough reflex, either as:

Expectorants : stimulate body to hydrate & thin the

mucus eg. Guiphenesine

Mucolytic agent: Helps to make mucus thin e.g. oralCarbocystein, Ambroxol, Bromhexine or inhaled

acetylcysteine. Adhesives / surfactants: Reduces affinity between

secretions & biological surfaces eg. Ammoniumchloride, potassium iodide


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Combination cough medicationsCommon available combinations:

Antitussive + Antihistamine

Decongestant + Antihistamine

Decongestant + Mucolytic

Expectorant + Mucolytic Expectorant + Antiadhesive

Expectorants + Brochodilator

Combinations that should be banned

Montlukast + Expectorants

Expectorants + Zinc / Calcium

Mucolytic + Amoxycillin


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Herbal medicines & Home

remedies

Mostly cough suppressants act as demulsifying

agents soothing for throat

Contain various combinations of honey, tulsi,

ginger, methi.

Recent preparations with dry ivy leaf extract

Give temporary relief

Do not treat underlying cause

Generally safe & non addictive


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Fever

Elevation of body temperature above normal range of 36.5

37.5 C (98100 F) due to elevated temperature regulatory

set point is fever.

Elevation of body temperature greater than or equal to 41.5

C (106.7 F) due to elevated temperature regulatory centreis hyperpyrexia which is fever.

Elevation of body temperature without elevated temperature

regulatory set point as in elevated environmental

temperature or heat stroke is hyperthermia

In hyperthermia the body temperature rises above its set point &hence is notfever!


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Thermoregulatory mechanism

The brain orchestrates heat effector mechanisms

via the Autonomous Nervous system:

Increased heat production:

by increased muscle tone, shivering

hormones like epinephrine

Prevention of heat loss

vasoconstriction.

This temperature regulation is controlled in the hypothalamus

Thermoreg lator centre & afferent & efferent arms


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Thermoregulatory centre & afferent & efferent arms

The preoptic region, in & near

the rostral hypothalamus,acts as a coordinating center.

The preoptic area contains

neurons that are sensitive to

subtle changes in hypothalamicor core temperature & also

receive somatosensory

input from spinal & skin

thermoreceptors & integrate

central and peripheral thermal

information

M h i f f


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Mechanism of fever

Fever & Hyperpyrexia result from elevation of

thermoregulatory set point in response to chemicalmediators called pyrogens.

Pyrogens are generally immune mediated cytokines

eg. IL 1, IL 6, TNF generally released frommacrophages engulfing various pathogens.

These cytokines then bind with endothelial receptors on

vessel walls activating the arachidonic acid

pathwayformation of PGE2mediator of fever(COX2)

by acting on the preoptic area of hypothalamusfever response

Body responses to temperature variations


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Body responses to temperature variationsEffector Response to low temperature Response to high temperature

Smooth

muscles in

arterioles in

the skin.

Muscles contractVasoconstriction.

Extremities can turn blue and feel cold and

can even be damaged (frostbite).

Muscles relaxvasodilation. More

heat is carried from the core to the

surfacelost by convection & Skinturns red.

Sweat glands No sweat produced. Glands secrete sweat onto surface

of skinevaporates, it takes heat

from the body

Erector pili

muscles in

skin

Muscles contract, raising skin hairs and

trapping an insulating layer of still, warm

air next to the skin.

Muscles relax, lowering the skin hairs

and allowing air to circulate over the

skin convection and evaporation.

Skeletal

muscles

Shivering: Muscles contract & relax

repeatedly, generating heat by friction &

metabolic reactions

No shivering.

Adrenal &

thyroid glands

Glands secrete adrenaline and thyroxine

respectivelyincreases the metabolic rate

in different tissues generating heat.

Glands stop secreting adrenaline &

thyroxine.

Behavior Curling up, huddling, finding

shelter, putting on more clothes.

Stretching out, finding shade,

removing clothes


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Why fever?

Fever is a very energy consuming process thatevolution has preferred to persistwhy?

It is presumed that fever improves host immune

response:Increased mobility of leukocytes

Enhanced leukocytes phagocytosis

Endotoxin effects decreasedIncreased proliferation of T cells

Those with bacterial infection are seen to have lower mortalitywhen associated with fever.


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Why treat fever?

Although fever seems to be beneficial to the host, thediscomfort associated with fever eg. Malaise, headache,

tachycardia, hypertension necessitates treating the fever.

Certain high risk patients eg. Congenital heart diseases esp

with LR shunt, certain metabolic disorders & those with

H/O febrile convulsions as well as epilepsy benefit from

controlling fevers.

Fever controlling medications do not alter the course of the disease causing the fever


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Treatment of fever

Physical methods:

Sponging natural sweating areas of the body i.e. head,

arms, legs, axilla & scrotum.

Sponge with plain water or with salt or cologne added.

Preferable to use warm water.temp body-water = 2OF

Avoid blocking sweat pores with oil, woolen clothes.

Keep the surroundings cool

Keep well hydrated

T f f


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Treatment of feverMedications:

Paracetamol: aniline analgesic which is not an NSAID. Weak inhibitor ofCOX.

Rapidly absorbed with/ without food

Onset of action 11minutes

Duration of action 4 hours.

Dose related liver toxicity.

Paracetamol in regular dosage safe in G6PD deficiency

Ibuprofen: Nonselective COX inhibitor NSAID

.Rapidly absorbed with/ without food

. Rapid onset of action

. Duration of action 8 hours

. Because of nonselective COX inhibition G I disturbance is common.

Ibuprofen not safe in G6PD deficiency

Other NSAIDs


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Other NSAIDs

1) NONSELECTIVE COX INHIBITORS

- acetylsalicylic acid at high dosage

- diclofenac - ibuprofen

- ketoprofen

- flurbiprofen

- indomethacin

- piroxicam

- naproxen

2) COX-1 SELECTIVE INHIBITORS - acetylsalicylic acid at low dosage

3) MORE COX-2 SELECTIVE INHIBITORS

- nimesulid

- nabumeton

4) COX-2 SELECTIVE INHIBITORS

- celecoxib

- etorcoxib -


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Commonly used drugs in coughand cold preparations


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Chlorpheniramine maleate

Class - Antihistamines

Antihistaminic action :

Blocks the action of histamine (a substance causes

allergic symptoms)

Promptly relieves symptoms in Rhinitis (sneezing,

itching of eyes, nose & throat)

Anticholinergic action:

reduce secretion - Rhinorrhoea


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Chlorpheniramine maleate

Chlorpheniramine relieves

Red, itchy, watery eyes

Sneezing

Itchy nose or throat

Runny nose (Rhinorrhoea)

Chlorpheniramine helps control the symptoms of

Common Cold


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Phenylephrine Hydrochloride

Nasal Decongestant

Decongestants are the drugs of choice for a

stuffy, congested nose

Decongestants act by narrowing the blood

vessels in the nose, leading to decreasedblood flow in the nasal tissues and reduced

leakage of fluid from the nose


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Phenylephrine Hydrochloride

Nasal Decongestant

Direct Sympathomimetic

Selective alpha1 agonist action

Act on alpha adrenergic receptors in the mucosa of

the respiratory tract producing vasoconstriction

which results in shrinkage of swollen mucus

Relieves Stuffy Congested Nose


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Paracetamol

Paracetamolis one of the most popular andwidely used drugs for the treatment of pain and

fever

Central Analgesic Actionraises pain

threshold

Anti-pyretic action

Good safety profile

Relieves fever, sore throat and body ache

N h i f A ti f


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Newer mechanism of Action for

Paracetamol

Cananbinoids have a role in modulation of

pain (decrease the pain)

Active metabolite of PCM goes and bind to

cannabinoid receptor

Analgesic effect of paracetamolis due to the indirect activation ofcannabinoid CB(1) receptors

CNS Drug Rev.2006 Fall-Winter;12(3-4):250-75.
http://www.ncbi.nlm.nih.gov/pubmed/17227290http://www.ncbi.nlm.nih.gov/pubmed/17227290http://www.ncbi.nlm.nih.gov/pubmed/17227290


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Caffeine

Methyl xanthine alkaloid

Consumed as beverages

CNS Stimulant primarily affect the higher centers

Produces

Sense of well being,

Alertness,

Beats bordem,

Allays fatigue,

Improve performance


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Sales Training

Dextromethorphan Hydrobromide

(DMR)

Non - narcotic cough suppressant (anti tussive).

Acts centrally on cough centre, (Medulla) andelevates the threshold for coughing.

Equipotent to codeine in depressing cough reflex.

D t th h


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Sales Training

Dextromethorphan

Hydrobromide (DMR)

Average dose is 10 to 30 mg 3 to 6 timesdaily.

Has no expectoration action and does not

inhibit ciliary action. Rapidly absorbed from

G.I. Tract.

Exerts effect within 15-30 minutes after oral

administration.

Duration of action is 5-6 hours.

Metabolized in the liver.


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Sales Training

Cough suppressants with

equipotent doses

Dextromethorphan 10 mg

Codeine 15 mg Noscapine 15 mg

Pholcodeine 10 mg


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Favorable Features of


Equipotent antitussive to Codeine,

Pholcodiene which are narcotic.

No addictive properties.

Does not cause CNS depression nor it

affects respiratory rate.

Sales Training


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Sales Training

Favorable Features of


Does not cause drowsiness, constipation

unlike codeine.

Is safe & effective.


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Sales Training

Guaiphenesin

Most commonly used expectorant.

Often used singly or in combination.

Readily absorbed from GI tract

Increases the output of respiratory tract fluids, this

helps to liquefy the thick mucus.

Though not a cough suppressant reduces the intensityand frequency of dry or productive cough.


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Sales Training

Reference

Guaiphenesin

From a study in 239 patients it wasreported that Guaiphenesin reduced cough

intensity and frequency in patient with dry or

productive cough and helped to thin

sputum.

RE Robinson et al, Robins, Curr ther Research, 1977 : 22 ;

284


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Thank you

pediatric cough cme

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