Have you ever had a cough that lingered for days, even weeks, after the congestion and exhaustion of a cold or flu was gone? If you used cough drops to soothe and calm your throat, you may have inadvertently done the opposite.
Robert Mead, M.D., noticed that people who came to his office to address a lingering cough often told him they weren’t taking any medicine for it… as they popped a cough drop. Some of his patients were taking 20 drops a day! On a hunch, Dr. Mead told them to stop the cough drops and see what happened. Most often, the cough was gone in a day or two.
After noticing this trend, Dr. Mead asked the Wisconsin Research and Education Network (WREN) to run a study. Their research, published in the Journal of the American Board of Family Medicine in 2018, confirmed Dr. Mead’s insight. WREN studied more than 500 people in rural, suburban, and urban Wisconsin clinics.
Why Menthol May Be the Cough Culprit
Most cough drops use menthol, a mint extract, to cool your throat and suppress your cough, though some brands use honey or other ingredients.
So when the researchers surveyed the patients, they didn’t just ask if they were taking cough drops, but which brands and how many. About 90% of them were taking cough drops that contained menthol.
The more severe the person rated their cough, the more cough drops they would take. This finding was not surprising, the researchers wrote, because, of course, if your cough is worsening, you’ll likely want more soothing cough drops. However, they were surprised to find that, among those taking menthol-containing drops, the higher the dose of menthol in the cough drop, the worse the individuals rated their coughs.
The scientists noted it was unlikely that people were comparing the menthol contents of different drops and seeking higher doses based on the severity of their coughs, thus, it was reasonable to suggest that perhaps the menthol itself was exacerbating their coughs.
The researchers also found that it wasn’t just how much menthol each individual drop contained but how much menthol accumulated in someone’s body over the day.
So why was menthol associated with a worse cough in the long run? Researchers theorized it may be due to tachyphylaxis, a medical term describing a rapid decrease in response to repeated doses of a drug over a short time period.
Researchers noted that while menthol may initially suppress cough reflexes, repeated use in quick succession may cause the body to become desensitized to its effects, leading to a worsening of cough symptoms.
The study focused on people whose cough could be described as a “tickle in the throat,” a cough that can be triggered by talking, one that is not productive (doesn’t bring up phlegm), and with which the patient has no fever.
Patience, Natural Remedies, and Dexamethasone: How to Get Rid of a Lingering Cough
I spoke with Dr. Mead and told him I had that very cough described above, and I’d been using 10 or more cough drops a day, often coughing while the drop was in my mouth! I stopped the cough drops as soon as I read about his study.
“When was that?” he asked.
“Two days ago,” I responded.
“Was your coughing worse yesterday?”
“Yes, it was, but much better today.”
“That’s the rebound effect of the menthol; it takes a day or so to get out of your body.”
When it comes to easing coughs, what does Dr. Mead suggest to his patients now? Patience, and if the coughing is too disruptive, choosing a cough syrup that has dexamethasone – a corticosteroid that works by reducing inflammation – is often effective at suppressing it.
Natural Cough Remedies
Before you reach for the lozenges or cough syrups, there are a few natural remedies you can try to ease your throat:
- Honey: A review of six randomized trials in children suggested that honey likely relieved cough symptoms, for the first three days it was given. After three days, the benefit was no longer significant.
- Gargling saltwater: Experts suggest that gargling a saltwater solution can help relieve throat pain, which you may experience as a result of coughing.
- Sucking on ice chips: The cold sensation may help ease a sore throat or cough, much like a cooling lozenge.
