Treatment of cough at community pharmacy

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 a viral URTI. They will often
be associated with other symptoms of a cold. The evidence to support
the use of cough suppressants and expectorants is not strong but some
patients report finding them helpful.

What you need to know

Age (approximate)

Baby, child, adult

Duration

Nature

Dry or productive

Associated symptoms

Cold, sore throat, fever
Sputum production
Chest pain
Shortness of breath
Wheeze

Previous history

Chronic bronchitis
Asthma
Diabetes
Heart disease
Gastro-oesophageal reflux
Smoking habit

Present medication

Significance of questions and answers

Age

Establishing who the patient is – child or adult – will influence the

choice of treatment and whether referral is necessary.

Duration

Most coughs are self-limiting and will be better within a few days with

or without treatment. In general, a cough of longer than 2 weeks’

duration that is not improving should be referred to the doctor for

further investigation.

Patients are often concerned when a cough has lasted for, what

seems to them to be, a long time. They may be worried that because

the cough has not resolved, it may have a serious cause.

Nature of cough

Unproductive (dry, tickly or tight)

In an unproductive cough no sputum is produced. These coughs are

usually caused by viral infection and are self-limiting.

Productive (chesty or loose)

Sputum is normally produced. It is an oversecretion of sputum that

leads to coughing. Oversecretion may be caused by irritation of the

airways due to infection, allergy, etc. or when the cilia are not working

properly (e.g. in smokers). Non-coloured (clear or whitish) sputum is

uninfected and known as mucoid.

Coloured sputum may sometimes indicate a bacterial chest infection

such as bronchitis or pneumonia and require referral. In these

situations the sputum is described as green, yellow or rust-coloured

thick mucus and the patient is more unwell usually with a raised

temperature, shivers and sweats. Sometimes blood may be present in

the sputum (haemoptysis), with a colour ranging from pink to deep

red. Blood may be an indication of a relatively minor problem such as

a burst capillary following a bout of violent coughing during an acute

infection, but may be a warning of more serious problems. Haemoptysis

is an indication for referral.

Antibacterials/antibiotics are not usually indicated for previously

healthy people with acute bronchitis. Most cases of acute bronchitis

are caused by viral infections, so antibacterials will not help. Two

systematic reviews of antibacterials for acute bronchitis found only

slight benefit, possibly reducing the duration of illness by about half a

day. Some people who have a tendency towards asthma develop a

wheezy bronchitis with a respiratory viral infection. They may benefit

from inhalation treatment used in asthma.

If a person has had repeated episodes of bronchitis over the years

they might have chronic bronchitis (defined as a chronic cough and/or

mucus production for at least 3 months in at least 2 consecutive years

when other causes of chronic cough have been excluded). So careful

questioning is important to determine this.``

There is general consensus that antibacterials should be considered

if the person is elderly, has reduced resistance to infection, has

co-morbidity (such as diabetes or heart failure) or is deteriorating

clinically.

In heart failure and mitral stenosis the sputum is sometimes described

as pink and frothy or can be bright red. Confirming symptoms would

be breathlessness (especially in bed during the night) and swollen

ankles.

Tuberculosis (TB)

Until recently thought of as a disease of the past, the number of TB

cases has been rising in the UK and there is increasing concern about

resistant strains. Chronic cough with haemoptysis associated with

chronic fever and night sweats are classical symptoms. TB is largely

a disease of poverty and more likely to present in disadvantaged

communities. In the UK most cases of respiratory TB are seen in ethnic

minority groups, especially Indian and Africans. Human immunodeficiency

virus (HIV) infection is a significant risk factor for the development

of respiratory TB.

Croup (acute laryngotracheitis)

Croup usually occurs in infants. The cough has a harsh barking

quality. It develops 1 day or so after the onset of coldlike symptoms.

It is often associated with difficulty in breathing and an inspiratory

stridor (noise in throat on breathing in). Referral is necessary.

Whooping cough (pertussis)

Whooping cough starts with catarrhal symptoms. The characteristic

whoop is not present in the early stages of infection. The whoop is the

sound produced when breathing in after a paroxysm of coughing.

The bouts of coughing prevent normal breathing and the whoop

represents the desperate attempt to get a breath. Referral is necessary.

Associated symptoms

Cold, sore throat and catarrh may be associated with a cough. Often

there may be a temperature and generalised muscular aches present.

This would be in keeping with a viral infection and be self-limiting.

Chest pain, shortness of breath or wheezing are all indications for

referral.

Postnasal drip

Postnasal drip is a common cause of coughing and may be due to

sinusitis.

Previous history

Certain cough remedies are best avoided in diabetics and anyone with

heart disease or hypertension.

Chronic bronchitis

Questioning may reveal a history of chronic bronchitis, which is being

treated by the doctor with antibiotics. In this situation further treatment

may be possible with an appropriate cough medicine.

Asthma

A recurrent night-time cough can indicate asthma, especially in

children, and should be referred. Asthma may sometimes present as

a chronic cough without wheezing. A family history of eczema, hay

fever and asthma is worth asking about. Patients with such a family

history appear to be more prone to extended episodes of coughing

following a simple URTI.

Cardiovascular

Coughing can be a symptom of heart failure (see p. 60). If there is

a history of heart disease, especially with a persisting cough, then

referral is advisable.

Gastro-oesophageal

Gastro-oesophageal reflux can cause coughing. Sometimes such reflux

is asymptomatic apart from coughing. Some patients are aware of acid

coming up into their throat at night when they are in bed.

Smoking habit 

Smoking will exacerbate a cough and can cause coughing since it is

irritating to the lungs. One in three long-term smokers develop a

chronic cough. If coughing is recurrent and persistent, the pharmacist

is in a good position to offer health education advice about the

benefits of stopping smoking, suggesting NRT where appropriate.

However, on stopping, the cough may initially become worse as the

cleaning action of the cilia is re-established during the first few days

and it is worth mentioning this. Smokers may assume their cough is

harmless, and it is always important to ask about any change in the

nature of the cough that might suggest a serious cause.

Present medication

It is always essential to establish which medicines are currently being

taken. This includes those prescribed by a doctor and any bought

OTC, borrowed from a friend or neighbour or rediscovered in the

family medicine chest. It is important to remember the possibility of

interactions with cough medicine.

It is also useful to know which cough medicines have been

tried already. The pharmacist may decide that an inappropriate

preparation has been taken, e.g. a cough suppressant for a productive

cough. If one or more appropriate remedies have been tried

for an appropriate length of time without success, then referral is

advisable.

Angiotensin-converting enzyme (ACE) inhibitors

Chronic coughing may occur in patients, particularly women,

taking ACE inhibitors such as enalapril, captopril, lisinopril and

ramipril. Patients may develop the cough within days of starting

treatment or after a period of a few weeks or even months. The

exact incidence of the reaction is not known and estimates vary

from 2% to 10% of patients taking ACE inhibitors. ACE inhibitors

control the breakdown of bradykinin and other kinins in the

lungs, which can trigger a cough. Typically the cough is irritating,

non-productive and persistent. Any ACE inhibitor may induce

coughing and there seems to be little advantage to be gained

in changing from one to another. The cough may resolve or may

persist; in some patients the cough is so troublesome and distressing

that ACE inhibitor therapy may have to be discontinued. Any patients

in whom medication is suspected as the cause of a cough should be

referred to their doctor. Angiotensin 2 receptor antagonists, which

have similar properties to ACE inhibitors and which do not affect

bradykinin, can be used as an alternative preparation if cough is

a problem.

Treatment timescale

Depending on the length of time the patient has had the cough and

once the pharmacist has recommended an appropriate treatment,

patients should see their doctor 2 weeks after the cough started if it

has not improved.

Management

Pharmacists are well aware of the debate about the clinical efficacy of

the cough remedies available OTC. In particular, the lack of scientific

evidence that expectorants have any effect and the use of combinations

with apparently contradictory ingredients have been cited.

However, many people who visit the pharmacy for advice do so

because they want some relief from their symptoms and, while the

effectiveness of cough remedies remains unproven, they can have a

useful placebo effect.

The choice of treatment depends on the type of cough. Suppressants

(e.g. pholcodine) are used to treat unproductive coughs, while expectorants

such as guaifenesin (guaiphenesin) are used in the treatment of

productive coughs. The pharmacist should check that the preparation

contains an appropriate dose, since some products contain subtherapeutic

amounts. Demulcents like Simple Linctus that soothe the throat

are particularly useful in children and pregnant women as they contain

no active ingredients.

The BNF gives the following guidance.

Cough suppressants

Controlled trials have not confirmed any significant effect of cough
suppressants over placebo in symptom reduction.

Codeine/pholcodine

Pholcodine has several advantages over codeine in that it produces
fewer side-effects (even at OTC doses codeine can cause constipation
and, at high doses, respiratory depression) and pholcodine is less liable
to be abused. For these reasons, codeine is best avoided in the treatment
of children’s coughs and should never be used in children under
1 year. Both pholcodine and codeine can induce drowsiness, although
in practice this does not appear to be 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.
Sales often have to be refused because of knowledge or likelihood of
abuse. Pholcodine can be given at a dose of 5 mg to children over
2 years of age (5 mg of pholcodine is contained in 5 ml of pholcodine
linctus BP). Adults may take doses of up to 15 mg three or four times
daily. The drug has a long half-life and may be more appropriately
given as a twice-daily dose.

Dextromethorphan

Dextromethorphan is less potent than pholcodine and codeine. It is
generally non-sedating and has few side-effects. Occasionally, drowsiness
had been reported but, as for 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 purchases
are made.

Demulcents

Preparations such as glycerin, lemon and honey or Simple Linctus are
popular remedies and are useful for their soothing effect. They do not
contain any active ingredient and are considered to be safe in children
and pregnant women. Their pleasant taste makes them particularly
suitable for children but their high syrup content should be noted.

Expectorants

Two mechanisms have been proposed for expectorants. They may act
directly by stimulating bronchial mucus secretion, leading to increased
liquefying of sputum, making it easier to cough up. Alternatively, they
may act indirectly via irritation of the gastrointestinal (GI) tract,
which has a subsequent action on the respiratory system resulting
in increased mucus secretion. This latter theory has less convincing
evidence than the former to support it.

Guaifenesin (guaiphenesin)

Guaifenesin is commonly found in cough remedies. In adults, the dose
required to produce expectoration is 100–200 mg, so in order to have
a theoretical chance of effectiveness, any product recommended
should contain a sufficiently high dose. Some OTC preparations contain
subtherapeutic doses. In the USA, the Food and Drugs Administration
(FDA, the licensing body) reviewed OTC medicines, and
evidence from studies supporting guaifenesin was sufficiently strong
for the FDA to be convinced of its efficacy.

Cough remedies: other constituents

Antihistamines

Examples used in OTC products include diphenhydramine and
promethazine. Theoretically these reduce the frequency of coughing
and have a drying effect on secretions, but in practice they also induce
drowsiness. Combinations of antihistamines with expectorants are
illogical and best avoided. A combination of an antihistamine and a
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. This is 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.
Interactions. Traditional antihistamines should not be used by patients
who are taking phenothiazines and tricyclic antidepressants because
of additive anticholinergic and sedative effects. Increased sedation will
also occur with any drug that has a CNS depressant effect. Alcohol
should be avoided because this will also lead to increased drowsiness.

Sympathomimetics

Pseudoephedrine is the most commonly used oral decongestant included
in cough and cold remedies for its bronchodilatory
and decongestant actions. It has a stimulant effect that may lead
to a sleepless night if taken close to bedtime. It may be useful if the
patient has a blocked nose as well as a cough and an expectorant/
decongestant combination can be useful in productive coughs. Sympathomimetics
can cause raised blood pressure, stimulation of the
heart and alterations in diabetic control. Oral sympathomimetics
should be used with caution in patients with
diabetes
coronary heart disease (e.g. angina)
hypertension
hyperthyroidism
Interactions. Sympathomimetics should be avoided by patients taking
monoamine oxidase inhibitors (e.g. phenelzine)
reversible inhibitors of monoamine oxidase A (e.g. moclobemide)
beta-blockers
tricylic antidepressants (e.g. amitriptyline); a theoretical interaction
which does not seem to cause problems in practice.

Theophylline

Theophylline is sometimes included in cough remedies for its bronchodilator
effect. OTC medicines containing theophylline should
not be taken at the same time as prescribed theophylline since
toxic blood levels and side-effects may occur. The action of theophylline
can be potentiated by some drugs, e.g. cimetidine and
erythromycin.
Levels of theophylline in the blood are reduced by smoking and
drugs such as carbamazepine, phenytoin and rifampicin that induce
liver enzymes, so that the metabolism of theophylline is increased and
lower serum levels result.
Side-effects include GI irritation, nausea, palpitations, insomnia and
headaches. The adult dose is typically 120 mg three or four times daily.
It is not recommended in children. Before selling any OTC product
containing theophylline, check that the patient is not already taking
the drug on prescription.