Cough

Introduction

Cough is the most common respiratory symptom and is usually self-limiting (will resolve in 3-4 weeks without the need for antibiotics).

Coughing is the body's defence mechanism to clear the airways of foreign bodies and particulate matter.

Questions to Ask the Patient

Some important information to be gathered include

Duration of the cough

Duration longer than 2-3 weeks with no improvement or is getting worse suggests non-acute cause of cough and requires further investigation, such as tuberculosis, asthma, chronic bronchitis, COPD, lung cancer, heart failure and gastroesophageal reflux.

Chest pain, haemoptysis (coughing up blood), shortness of breath and wheezing

Suggest possible sinister pathology or severe cases of simple viral infection, and requires further investigation.

Age

Children or adult? If children, how many years old?

Persistent nocturnal cough in children

Suggests possible asthma, especially those with family history.

Nature of cough

Coughs can be described as productive (chesty) or non-productive (dry, tight, tickly).
However, many patients will say that they are not producing sputum, although they may go onto say that they 'can feel it on their chest'. In these cases, the cough is probably productive in nature and should be treated as such.

Sputum colour

Non-coloured sputum (clear or whitish) typically indicates the absence of infection.
Purulent sputum (thick and yellow or green) may suggest a bacterial or viral infection, but does not automatically require antibiotics.
Antibiotic treatment is warranted in cases of severe symptoms, particularly significant changes in sputum colour and thickness beyond normal, systemic unwellness, or a high risk of serious complications due to pre-existing comorbidities.
Haemoptysis, the presence of blood in sputum, ranging in colour from pink to deep red or brown, necessitates immediate medical referral.

Smoking

Patients who smoke are more prone to chronic and recurrent cough. Over time, this might develop into chronic bronchitis and COPD.

NOTE: Post-nasal drip can sometimes cause a cough and may be due to sinusitis. “Post-nasal drip” is when mucus from your nose or sinuses drips down the back of your throat.

Medications

Depending on the nature of cough, the OTC medication differs.

Productive (chesty)

Expectorants, e.g. guaifenesin, ammonium chloride, ipecacuanha
Mucolytics, e.g. bromhexine, ambroxol (metabolite of bromhexine), acetylcysteine, carbocisteine, cyclidrol

Non-productive (dry, tight, tickly)

Cough suppressants (antitussives), e.g. pholcodine, dextromethorphan, cloperastine

NOTE: Pholcodine-containing cough and cold medicines were removed from the market following a review into their link with rare serious allergic reactions to NMBAs used in anesthesia.

Antihistamines have been included in cough remedies for decades.

Their mechanism of action is thought to be through the anticholinergic-like drying action on the mucous membranes and not via histamine.
Citric acid-induced cough studies have demonstrated significant antitussive activity compared with placebo, and results from chronic cough trials support an antitussive activity for diphenhydramine. However, trials that showed a significant reduction in cough frequency suffered from having small patient numbers, thus limiting their usefulness.
In practice, diphenhydramine also induces drowsiness.

Demulcents, such as simple linctus, glycerol and honey, which soothe the throat, are particularly useful in children and pregnant women.

However, honey should not be given to children under one year old due to the risk of infant botulism.

NOTE: All active ingredients to treat cough were brought to the market many years ago when clinical trials suffered from flaws in study design compared with today's standard.

Paediatric

Due to growing evidence of the potential harm that cough and cold medications can pose to young children, either due to adverse effects or from accidental inappropriate dosing,

Since 2007, the US Food and Drug Administration (FDA) recommend OTC cough and cold products should not be used to treat children younger than 2 years.
On the other hand, based on the lack of efficacy and potential harm, starting year 2009, the UK MHRA/CHM recommended that cough and cold mixtures should not be used in children under 6 years of age, and should only be used in children aged 6 to 12 on the advice of a pharmacist or doctor.

At Malaysia, we are still practicing giving cough and cold mixtures for patients aged above 2 years old.

Combination Products

Cough, cold, sore throat and rhinitis often coexist. Hence, many OTC cough preparations are combinations of agents.

Some of these include ingredients, such as decongestants, that target other aspects of the common cold.

It should be noted that some combination products contain sub-therapeutic doses of the active ingredients, while a few contain illogical combinations such as cough suppressants with an expectorant, or an antihistamine with an expectorant.

If possible, these should be avoided.
Nonetheless, a combination of a sedating antihistamine and a cough suppressant may be useful in that antihistamines can help to dry up secretions through their antimuscarinic side effects; therefore, this combination can be given as a night-time dose if the cough is disturbing sleep.

Herbal Products

A number of herbal ingredients are included in cough medicines; for example, Pelargonium sidoides (geranium), echinacea, Andrographis paniculata (green chiretta), ivy, primrose and thyme.

In Wagner’s review, very low-quality evidence was found that ivy, primrose or thyme significantly reduced cough compared with placebo in people with acute cough.

Medicine-induced Cough

A 50-year-old female customer walked into your pharmacy to have her usual medication filled; a box of Glucophage XR 750 mg and a bottle of Coversyl 5 mg.

She was then complaining that she has been having a cough, with very little phlegm for quite some time.
She is wondering on how long a cough usually last and what remedy that will really soothe her cough.

In the conversation,

You explained to the customer that cough is usually self-limiting in nature
You realized that the customer has been having the cough for 3 months and tried some remedies but all did not really work.

Well, this could be a typical case presentation of patient experiencing dry cough as a side effect of ACE inhibitor. Does it ring a bell now?

You decide to investigate further.

The customer replied that the cough started after she started taking Coversyl 5 mg for high blood pressure.
You explained to the customer on your concern and refer her back to her family doctor to review her blood pressure medication.
Cough may start within days of starting ACE inhibitor treatment or after a few weeks or even months, and is estimated to affect from 2-10% of patients.
Angiotensin II receptor antagonists, also known as the "sartans", which have properties similar to ACE inhibitors but do not affect bradykinin, can be used as an alternative treatment.

Remember, when you are practicing as pharmacist, NEVER FORGET what you have learned at university.

In examination, we know there is a problem existed in the question, so we try to be extra careful.
In real life, it is where we should be 200% more careful, because we never know where and when the problem is.

Diabetes

In short-term acute conditions, the amount of sugar found in cough medicines is relatively unimportant.

Diabetic control is often upset during infections and the additional sugar is not considered to be a major problem.
Nevertheless, many people with diabetes may prefer a sugar-free product.

Summary

Many patients are unaware that a cough can persist for three weeks or more after a severe cold, influenza, or COVID-19.

The viral infection usually lasts for a few days, but damage to the respiratory tract lining causing irritation takes longer to heal and hence a cough can last for several weeks.

Search This Blog

Rx Note