Responding to symptoms Lecture 2

Cough

Respiratory

system

Background :General review of the anatomy of the respiratory tract :

1- upper respiratory tract :

Nasal cavity :-Is the internal portion of the nose -Connected to the pharynx -Function is :

1- filters out large dust particles 2- Warms and moisten incoming air

Pharynx :

Divided into 3 sections :1- nasopharynx : exchange air with the nasal cavity and move the particle matters towards the mouth 2- oropharynx3- laryngopharynx : both serve as common pathway for air and food

Larynx ( voice box )

This is a short passage that connect the pharynx with the trachea

Lower respiratory tract :

Trachea & bronchi :

The trachea connects the larynx with the bronchi

The bronchi divided and sub divided into bronchioles

The terminal bronchioles give rise to alveoli wheregaseous exchange take place .

they acts as defense mechanism , cilia on the surface of cells beat upwards in organized waves of contraction , thus expelling foreign bodies

Cough :

Definition :

Coughing is a protective reflex action caused when the airway is being irritated or obstructed .

Its purpose is to clear the airway so that breathing can continue normally

The majority of coughs presenting in the pharmacy will be caused by viral infections , they will be often associated with other symptoms of cold

Cough may be classified as:

1- productive cough : phlegm is produced

2- dry cough : no phlegm production

Cough is most commonly associated with other respiratory tract infections

What you need to know :[ differential diagnosis ]

1- Age (approximate ) baby , child, adult …

-This will influence the choice of treatment and whether referral is necessary

2- Duration :

Most cough are self limited and will be better within a few days without treatment.

-Cough longer than 2 weeks’ duration that is not improving should be referred to the doctor for further investigation.

-Cough more than 3 months suggests tuberculosis or carcinoma

3- Nature ( dry or productive ):Dry cough : in this type no sputum is produced . Usually caused by viral infection and self limited

Productive cough : sputum is normally produced Over secretion may be caused by irritation of the airways due to infection ,allergy , ….etc

Sputum colour :-Mucoid ( clear & white ) is normally of little consequence and suggests that no infection is present

-Yellow , green or brown sputum , normally indicates infection , however mucopurulent sputum is probably caused by bacterial infection such as bronchitis or pneumonia and required referral to GP. In this case the patient is generally unwell and has raised temperature (fever )

-Heamoptysis: blood in the sputum , this may be rusted coloured (pneumonia ) or pink but thin and frothy ( left ventricular failure ) , or dark red ( carcinoma )

4- periodicity :

-Adults with recurrent cough might have chronic bronchitis especially if they smoke ( smoking cessacion will help reduce cough symptoms and complications )

-Recurrent cough in children who have family history of eczema , asthma or hay fever should be referred that they may required further investigations and pulmonary function tests (e.g peak expiratory flow assessment )

5- Associated symptoms

( cold , sore throat , fever ) may be associated with a cough There may be a raised temperature and muscular aches ( this would be in keeping with viral infections Shortness of breath , wheezing are all indicator of refer

tuberculosis ( TB): Chronic cough with hemoptysis associated with chronic fever and night sweats

croup (acute laryngotacheitis ) :-Usually in infants -The cough has a harsh barking quality -It develop one day or two after the onset of cold like symptoms -Often associated with difficulty in breathing and an inspiratory stridor ( noise in throat on breathing in ) referral is necessary

asthma :-Recurrent night time cough can indicate asthma especially in children and should be referred -A family history of aczema , asthma ,hay fever

cardiovascular :-Coughing can be symptom of heart failure-Patients may complain of productive ,frothy cough which may have pink –tinged sputum

smoking habits :-Smoking will exacerbate a cough and can cause coughing since it is irritating the lung -Smokers may assume their cough is harmless , it is always important to ask about any change in the nature of the cough that might suggest a serious cause

carcinoma of the lung :-Possibility increase in long term cigarette smokers who had have cough for several months -Sputum with blood -Weight loss-Fatigue -Dyspnea

Angiotensin-converting enzyme inhibitors (ACE inhibitors ):

-Patients taking ACEI (enalapril, captopril, lisinopril , ramipril ) may complain of chronic dry cough

-Patients may develop cough within days of starting treatment or after period of few weeks or months

When to refer :

1- cough for 2 weeks or more with no improvement 2- sputum ( yellow, green , pink , blood stained )3- chest pain4- shortness of breath 5- wheezing6- barking cough7- recurrent nocturnal cough in children 8- suspected adverse drug reaction

Management :

-The choice of treatment depend on the type of cough -They are many types :

1-cough suppressant ( for dry cough ):

-Mainly the opiate derivatives ( codeine , phlocodeine , dextromethorphan ) -They act centrally so the main side effect is sedation ( advice patient not to drive or operate machines )-Can cause respiratory depression ( contraindicated for asthmatic )-Dextromethorphan can be given for children older than 1 year but generally not recommended for children less than 5 years

2- Expectorants (productive cough )

-These are ammonium salts , ipecacuanha , guaifensine -Guaifensine should be recommended as first-line treatment fr productive cough

Practical points :

1- insulin dependent diabetics :

-Should be asked to monitor their blood glucose frequently because insulin requirements increased during acute infections.-May prefer low or sugar free syrups although the effect in blood sugar Is non-significant

2- alternative delivery routes :-Lozenges now are available to treat cough , it is more practical than syrups

3- steam inhalation :-

-Advice patient for steam inhalation especially in productive cough . It helps liquefy lung secretions

4- fluid intake :

- maintaining a high fluid intake helps to hydrates the lung and hot drinks can have soothing effects

A Cough Suppressants

1. Codeine/pholcodine Both are effective cough suppressants. Pholcodine has several advantages over the codeine, in that: a) It produces fewer side effects (at OTC doses codeine can cause constipation and at higher doses, respiratory depression) b) Pholcodine is less liable to abuse.

For these reasons, codeine is best avoided in the treatment of children’s coughs and should never be used in children under a year old.

• Both pholcodine and codeine can induce drowsiness, although in practice this does not appear to a problem. Nevertheless it is sensible to give an appropriate warning. • Codeine is well known as a drug of abuse and many pharmacists choose not to recommend it. • Dose: Pholcodine can be given at a dose of 5 mg to children over 2 years. Adults may take doses of up to 15 mg up to 3-4 times daily. The drug has a long half-life and may be more appropriately given as a twice daily dose.

2. Dextromethorphan

This is an effective but less potent cough suppressant than codeine and pholcodine. It is non-sedating and has few side effects. Occasionally drowsiness has been reported, but, as pholcodine, this does not seem to be a problem in practice. Dextromethorphan can be given to children of 2 years and over. Dextromethorphan was generally thought to have a low potential for abuse. However, there have been rare reports of mania following abuse and consumption of very large quantities, and pharmacists should be aware of this possibility if regular purchase is made

3. Demulcents Preparations such glycerine, lemon and honey are popular and useful for their soothing effects. They don’t contain active ingredients and are safe in children and pregnant women. Their pleasant taste makes them suitable for children but their high syrup content preclude their use in diabetics.

B -Expectorants Two mechanisms have been proposed for expectorants: They may act directly by stimulating bronchial mucus secretion, leading to increased liquefying sputum, making it easier to cough up.

They may act indirectly via irritation of the GIT which has a subsequent action on the respiratory system causing increased mucus secretion. The latter theory has less evidence.

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Cough remedies – other constituents

1. Antihistamines Examples used in OTC include diphenhydramine and promethazine.

In theory, they reduce the frequency of coughing and have a drying effect on secretions, but in practice they also induce drowsiness. ( may be useful in nocturnal cough )

Combinations of antihistamines with expectorants are illogical and best avoided.

A combination of antihistamine and cough suppressant may be useful in that antihistamines can help to dry up secretions, and when the combination is given as a night-time dose if the cough is disturbing sleep, a good night’s sleep will invariably follow – one of the rare occasions when a side effect proves useful.

The non-sedating antihistamines are less effective in symptomatic treatment of coughs and colds because of their less pronounced anticholinergic actions.

2. Sympathomimetics

Examples include pseudoephedrine and phenylpropanolamine. These are commonly included in cough and cold remedies for their bronchodilatory and decongestant actions.

Phenylpropanolamine is a weaker bronchodilator than ephedrine and pseudoephedrine.

They may be useful in productive coughs.

All three have a stimulant effect which lead to a sleepless night if taken close to bedtime. These drugs can cause raised blood pressure, stimulation of the heart and alterations in diabetic control. Oral sympathomimetics should not be recommended for patients with diabetes, coronary heart disease (angina), hypertension and hyperthyroidism

Practical Points

A. Diabetics Current thinking is that in short-term acute conditions, the amount of sugar in cough medicines for short-term use is relatively unimportant.

Diabetic control is often upset during infections and the additional sugar is not now considered to be a major problem.

Nevertheless many diabetic patients may prefer a sugar-free product, as will many other customers who wish to reduce sugar intake for themselves and for their children.

As part of their contribution to improving dental health, pharmacists can ensure that they stock and display a range of sugar-free medicines.

B. Steam inhalations

These can be very useful, especially in productive cough. The steam helps to liquify lung secretions, and patients find the warm moist air comforting. While there is no evidence that the addition of medications to the water produces better clinical effect than steam alone, some may prefer to add a preparation such as menthol and eucalyptus.

One teaspoonful of inhalation should be added to a pint of hot (not boiling) water and inhaled. Apart from the risk from scalding, boiling water volatilizes the constituents too quickly. A cloth/towel can be put over the head to trap the steam.

C. Fluid intake Maintaining a high fluid intake helps to hydrate the lungs and hot drinks can have soothing effect.

General advice with coughs and cold should be to increase fluid intake by around 2 litres a day.

Thank

you