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Pop into any pharmacy and walk over to the shelf where they keep the cough syrups. You will notice that there are so many brands of cough medicines, each claiming to be better than the others. You may even be familiar with some of them thanks to their extensive advertising on TV. Despite the extensive range of cough syrups, the truth is that most of them share the same ingredients. So what are these ingredients and what do they do?
One of the most common ingredients is guaifenesin. Guaifenesin is categorized as an expectorant. Expectorants help with productive cough by helping one expel phlegm and other secretions from the airway, reducing irritation and discomfort. Guaifenesin can be safely given to children. There are also no significant cautions or side effects associated with it and there are also no significant interactions with other prescription medicines. Diabetic patients can also look out for sugar-free formulations of guaifenesin.
The next few commonly available ingredients belong to the category of cough suppressants (or antitussives). These include codeine (which is not readily available over the counter these days), pholcodeine and dextromethorphan. Antitussives are often taken for non-productive cough but research has not been able to convincingly determine any benefits to taking antitussives. As such, most healthcare professionals recognize the limited role of cough suppressants and will often recommend patients to take more fluids instead.
Source: www.hcwreview.com
Codeine, pholcodeine and dextromethorphan should be taken cautiously due to the potential for adverse side effects and their ability to interact with prescription medication. Side effects can include sedation and constipation. Asthmatics should also be cautious when taking these medications as they may theoretically cause respiratory depression (medical term that is used to describe any condition in which an individual’s respiration has a rate below 12 breaths per minute or simply mean a sensation of difficulty in breathing). Codeine, pholcodeine and dextromethorphan should also be avoided by pregnant women in the third trimester.
Many cough mixtures and preparations available also include antihistamines and some of the commonly used antihistamines include diphenhydramine, chlorpheniramine, promethazine and triprolidine. Antihistamines are thought to help in cough by drying up the secretions from mucous membranes while the sedative effects can help a person suffering from cough to have a better night’s sleep. The side effects of antihistamines include dry mouth, constipation and sedation. Use of antihistamines in children should be done cautiously while their use for children below the age of 2 is very highly discouraged unless deemed necessary by a doctor.
Mr. Mark Cheong is a pharmacist currently working in Kuala Lumpur. His research interests lie in the implementation strategies of public health measures. Find out more about him at The Team page.
References
- British National Formulary, 66th Edition, September 2013
[This article belongs to The Malaysian Medical Gazette. Any republication (online or offline) without written permission from The Malaysian Medical Gazette is prohibited.]