The recent withdrawal of all pholcodine-containing cough medicines from the UK market has caused a significant media storm.

A large study has demonstrated that if you have consumed any products containing pholcodine in the 12 months prior to having a general anaesthetic which uses NMBA drugs, there is the potential for a life-threatening allergic reaction known as anaphylaxis.

NMBAs or neuromuscular blocking agents are commonly used as part of a general anaesthetic (GA), allowing muscle relaxation prior to a surgical procedure.

Pholcodine is referred to medically as an antitussive. Used in cold and flu preparations since the 1950s, it is an opiate (morphine based) product. It reduces the activity of the centre in the brain which sends signals to the muscles involved in coughing.

Cough is often described as the most troublesome part of any respiratory illness and makes up a vast number of GP and hospital consultations.

The UK Medicines Regulatory Health Authority (MHRA) describes the move as a precautionary measure.

The data from the study are robust, showing around a fourfold increase in the number anaphylactic reactions if pholcodine is used in the 12 months before a GA using NMBAs.

Yet the numbers of these reactions remain small at around one for every ten thousand procedures.

At the present time, those who have used such products and are awaiting a procedure that needs a GA are advised to discuss it with their GP or surgical team.

It is important to say that there is no increased risk if you have used a medicine containing pholcodine and are not awaiting a general anaesthetic.

There is data from a Norwegian study showing that this increased risk may persist for up to three years after using pholcodine. Again, the number of anaphylactic reactions remains small thankfully.

Currently, around twenty products have been removed from UK shelves. If a cough preparation contains pholcodine, it will be listed either on the label, or in the leaflet accompanying it.

The market for cough medicines is a multi-million-pound industry. While the majority are safe to use without consulting a doctor, it is important to always read the label.

Some will contain paracetamol and/or ibuprofen, as well as small amounts of alcohol. This is relevant as there is the potential to overdose if you are using these as well as maximum recommended doses of paracetamol or ibuprofen tablets.

Cough medicines contain various ingredients aimed at tackling the different symptoms of cold or flu.

Antitussives such as pholcodine or dextromethorphan aim to suppress an irritating cough. Expectorants, for example guaifenesin or ipecacuanha, loosen secretions, helping you to cough up sputum more easily.

Antihistamines reduce symptoms of congestion, as well as the amount of mucus the lungs produce.

Finally, decongestants, which include phenylephrine and ephedrine, work by narrowing blood vessels in the nose and lungs, so you feel less bunged up.

Cough medicines should not be used for anyone under the age recommended on the packaging.

Despite the impressive array of ingredients, there still remains little evidence to recommend these often expensive products over home remedies such as honey and lemon.

A viral respiratory tract infection should settle within two to three weeks, though sometimes the cough may persist a little longer.

There also remains the issue of whether a cough is just a simple viral infection which will resolve of its own, or a sign of another condition.

A bacterial chest infection may require antibiotics.

A cough made worse by exercise, with or without wheezing may be a sign of asthma.

Symptoms made worse by lying flat, or where you are coughing through the night, may be due to acid reflux.

You do not need to necessarily have heartburn, and this condition is sometimes referred to as silent reflux.

A cough may become a habit, such as a tick.

Perhaps the cough which is most important not to ignore is that for three weeks or more if you are a smoker. Though it is very easy to assign this to being a 'smoker’s cough', it may be a sign of lung cancer and should prompt an urgent GP appointment.

If you are confused about a cough that has persisted for more than a few weeks, it makes sense to arrange a consultation with your GP practice, where a clinician can review your symptoms, ask the relevant questions, and examine you as appropriate.

Dr. Zak Uddin is a General Practitioner