The next time your child has a cough, think, before you reach for that bottle of medicine. It may not offer the antidote you seek
A cough is one of the most common reasons for a visit to the GP. Parent anxiety and frustration over a cough forces them to spend billons of dollar each year on over-the counter cough syrups, which are generally not effective.
Do cough syrups work or you are wasting your hard earn money?
First, one needs to understand why coughs happen.
Coughing is a protective response of our body to keep our throat and chest clear from irritants and mucus which often happen after infection and aspiration. The infection could be a viral infection of the upper airways, such as colds or the flu, or a bacterial infection. Sometimes it can happen after allergy to dust mite, pollen and pet animal dander.
Most adults have up to two or three upper airway infections a year, but in children it happens more often and it may be 10 infections a year, particularly those who go to childcare.
Each cough occurs through the stimulation of a complex reflex arc. This is initiated by the irritation of cough receptors which are found in the breathing airways-large and smaller airway. These cough receptors respond to both mechanical and chemical stimuli. Chemical receptors sensitive to acid, heat, and capsaicin-like compounds trigger the cough reflex via activation of these receptors.
Once the cough receptor is stimulated it sends the message to a ‘cough centre’ in the medulla part of the brain, which itself may be under some control by higher cortical centres. The cough centre generates a signal that travels down the nerves to expiratory musculature to produce the cough.
How does the cough syrup claim to help?
Professor Christine Jenkins, respiratory physician at Sydney’s Concord Hospital, says while the pharmacy is stacked with cough remedies, most over-the-counter medications do not make a very big difference to coughs when there is an upper airway infection.
There are generally two types of cough syrups in the market. The expectorants such as guaifenesin, which help in loosening the mucus or phlegm and makes it easier to cough up. The other type is a cough suppressant such as codeine or dextromethorphan, which suppresses the urge to cough.
Dry cough mixtures generally contain cough suppressants, which are derived from opioids so they can cause drowsiness or constipation. The cough syrup used for chesty or moist cough often contain expectorants containing guaifenesin which helps in thinning and loosening the mucus which is easy to cough up.
There is no quick way to getting rid of a cough which is caused by a viral infection. But it usually clears up by its own
The cough mixtures may not fix the underlying reason to cough. Unfortunately, there is no strong evidence indicating that cough syrups are effective in alleviating symptoms of cough in both adults and children particularly they have no effect in reducing the duration of cough.
The study from Penn State Hershey Medical Centre stated that cough syrup and placebo have equal effects in treating cough in children. Another study published in Journal of Allergy and Clinical Immunology looked at the effectiveness of Phenylephrine, which is widely used in OTC medication for nasal congestion. It has not proved to be better than a sugar pill at alleviating symptoms.
There is no quick way to getting rid of a cough which is caused by a viral infection. But it usually clears up by its own, in about two weeks when the immune system has fought off the virus.
The key to the effective treatment of cough is to identify the underlying cause of the cough. Some cough mixtures contain medications like antihistaminic and decongestants to control symptoms of common cold. It is better to avoid syrups containing this medication, if cough is the only symptom.
Potential abuse and side effects
The OTC cough syrup containing dextromethorphan can be a popular drug of abuse among teens. The medication, if used frequently, over the recommended dose, particularly in children may lead to irritability, restlessness, lethargy, hallucination and hypertension. Occasional cases of death have also been reported when the medication has been combined with alcohol or illicit drugs. In addition, many of these cough products are elixirs, which may contain up to 25% alcohol by volume.
Keeping the nose moist by normal saline nasal sprays or drops is helpful particularly at night, especially for younger children
Generally, a bottle of cough syrup is sold in pharmacies for 10-15 dollars per bottle. It overall adds to the extra medical cost to the family. Traditional cost-effective homemade remedies such as a hot beverage of lemon and honey may be equally effective. Overall it can save families thousands of dollars every year. Cough syrups may also have adverse health effects on pregnant or breast-feeding women.
While there is some evidence that cough syrups containing expectorants or suppressants may reduce the intensity or frequency of a cough, they have no effect in reducing its duration.
American academy of Paediatrics says there is no reason parents should use these cough syrups in children under 6. Drug companies generally recommend them for children ages 4 and older.
So, what can you do for a cough?
Mentholated lozenges are an option as they keep the throat lubricated and reduce the urge to cough, particularly in adults. It may useful particularly when sitting in a pub, cinema, concert, office meeting or work environment when you want to avoid disturbing your friends or people sitting next to you.
Keeping yourself well hydrated by drinking plenty of fluids is always helpful. And keeping the nose moist by normal saline nasal sprays or drops is helpful particularly at night, especially for younger children.
When do you need to worry?
It is always advisable to seek advice from GP/specialist if you have
- Persistent cough for more than 2 weeks
- Cough fits—this may be a whooping cough
- Cough associated with breathing difficulties
- Cough over the time getting worse
- Cough associated with persistent high-grade temperature
- Cough with blood in mucus
- Cough associated with chest pain
The writer is a senior paediatrician, and Director, Western Specialist Centre