This article is more than 5 years old. Information may no longer be current.
Menthol cough drops may worsen cough
Click Here to Manage Email Alerts
Using menthol cough drops made some patients’ cough even worse, according to findings recently published in The Journal of the American Board of Family Medicine.
After observing a patient whose cough stopped 4 days after stopping menthol cough drop use, researchers conducted a survey of patients seeking medical care for cough from April 2016 to May 2017. The survey compiled data including age, cough drop use, cough drop type and quantity, cough duration and severity, and smoking status of 548 respondents. Among those, 363 reported using cough drops, and of those, 269 used cough drops that contained menthol.
Researchers found significant independent links established between cough severity and average menthol dose per cough drop (P = .007); number of cough drops consumed daily (P = .002) and total amount of menthol consumed per day (P = .001). These links stayed significant after controlling for the patient’s age, clinic site, season the cough occurred, sex, and smoking status, according to researchers. In addition, cough drop use was not linked to a patient’s overall cough severity (P = .09) but was linked to longer cough duration at the time of their appointment (P < .001). Based on their findings, researchers recommended that clinicians obtain a history of over-the-counter cough drop use when evaluating patients who have persistent and/or severe unexplained cough.
One of the study’s co-authors, David Hahn, MD, MS, of the University of Wisconsin School of Medicine and Public Health, outlined next steps for this line of research.
“I want to perform some healthy volunteer studies to see if repeated exposure to menthol has adverse effects on the cough reflex. There are fairly straightforward models in which healthy subjects inhale an irritant (such as citrate) that causes cough,” he said in an interview with Healio Family Medicine. “Previous studies document that inhaling a single dose of menthol before citrate will decrease the tendency to cough. We could find no studies of repeated or chronic exposure to menthol using this model, raising the question ‘Does repeated exposure lead to tolerance and/or rebound cough, similar to the severe rebound congestion that happens when people take repeated nasal sprays of Afrin for nasal stuffiness’?– by Janel Miller
Disclosure: The authors report no relevant financial disclosures.
Perspective
Back to Top
Daniel J. Hyman, DO
Postinfectious cough is a common complaint in primary care offices especially in the fall and winter months. Following a viral illness, a cough can persist for often more than 3 weeks and at times up to 8 weeks with no other etiology being found. Other causes for a chronic cough are underlying asthma exacerbations, untreated acid reflux and sinusitis with postnasal drip. Some medications have cough as a side effect, particularly the ACE inhibitor class of antihypertensives.
These causes for a persistent cough need to be ruled out with a good history and physical exam. Once these are ruled out along with an underlying pneumonia, we can then confidently diagnose a post infectious cough. These coughs will generally resolve on their own without any therapy; however, most patients understandably don’t want to wait that long. They will try many remedies including mentholated cough drops to help quell their cough.
As noted in this very interesting article, sometimes the remedy can make things worse. The article shows some compelling evidence that overuse of these medicated drops can make the cough worse and even prolong it. The evidence presented certainly is compelling that the association could be true.
Based on these findings, I will ask in more detail about the use of menthol in treatment of a chronic cough. Primary care physicians need to be diligent in their search for the cause of a chronic cough. Once more serious etiologies are ruled out, asking about over-the-counter medication use in more depth could be very helpful. The cause for the postinfectious cough remains unclear. It likely is related to chronic inflammation in the airways that takes time to resolve. Most treatments other than time are ineffective. The cause for a prolongation of these symptoms with menthol-based cough drops is also unclear. More research into the cause is needed.
Perspective
Back to Top
Roy Benaroch, MD
Johnson's paper focuses on a common problem in primary care: prolonged nonspecific cough. It's a frustrating problem for patients and physicians alike, but I'm not sure that this paper adds much to our knowledge. One cannot draw any sort of causal conclusion from the observations Johnson and colleagues made. Obviously, people with worse cough are going to seek more care of any kind. The survey doesn't support the idea that the patient in the case report had a cough caused by menthol cough drops. The brief literature review in the discussion shows only that menthol has been poorly studied as a cough reliever.What one can learn from this study is that many people use menthol-containing cough drops. Perhaps cough drops help, perhaps they don't; that one patient had an improved cough 4 days after abstaining from cough drops is, perhaps, interesting. But I don't think this study is likely to push the needle towards better evaluation and treatment of prolonged cough.
Click Here to Manage Email Alerts