Does cough medicine actually work?
It’s cold and flu season and you’re experiencing the worst of it -- the body aches, runny nose and, especially, the cough. You go to your local drug store to pick out the best over-the-counter medication and cough drops they have. In just two days, you start to feel better. But did the medication work or was it you simply believing that it did?
Coughs can be divided into two categories: acute cough, lasting up to three weeks, or chronic cough, lasting more than three weeks. Depending on the type of cough you may be experiencing, the “placebo effect” of medication can improve, or even eliminate, your symptoms.
Treating an acute cough
An acute cough is usually caused by viral infections such as the common cold virus. In this case, if you really think something is going to help your cough symptoms from a common cold, there’s a pretty good chance it will, no matter what you take. It’s similar to when your grandmother told you that a spoonful of honey with a few drops of vinegar would help your cough and you believed her. You typically felt better the next day. I often recommend that my patients take over-the-counter sugar-free cough lozenges. They won’t hurt the body, but the placebo effect may actually help relieve the cough.
Treating a chronic cough
A cough that lasts more than three weeks isn’t likely to be due to a common cold virus and you should consult your doctor. There are dozens of causes of chronic cough. Your doctor can often determine the cause based on your history and a physical examination. Additional testing, such as a chest x-ray or pulmonary function test may be necessary. Common causes of chronic cough include acid reflux; certain medications, such as those to treat blood pressure or heart failure; asthma; and nasal drainage.
Unlike acute coughs, over-the-counter cough medications may have a limited role in treating a chronic cough due to lung diseases such as chronic bronchitis or pulmonary fibrosis. Medication containing dextromorphan, like Robitussin-DM, has mild benefits.
Related: What causes that terrible nighttime cough?
Over-the-counter cough medication for treating coughs in children
Over-the-counter cough medications shouldn’t be used in children under the age of 6. Some medications shouldn’t be used in children under the age of 12. It’s best for a parent to speak with their pharmacist about which medications can be used safely in children but, again, these medications are generally no better than a placebo.
James Allen is a physician in the Division of Pulmonary Diseases at The Ohio State University Wexner Medical Center.