Should docs prescribe placebos for cough? The agave nectar story
© 2014 Roy Benaroch, MD
Coughing is among the most common symptoms that bring children to the doctor’s office. It’s an annoying symptom that disrupts the sleep of both the child and parents (though, oddly, siblings seldom complain—that may mean something.) Coughing itself is actually an essential physiologic mechanism to get dust and yuck up out of the lungs, but we all know that sometimes a little cough becomes a big or chronic cough that’s no fun at all. Big coughs also have the ability to make themselves worse though what’s called a “cough cycle”: person coughs, that irritates the throat, that triggers more mucus and more coughing, and the cycle continues. Fun!
So it’s understandable that people want some way to relieve coughs. We’re talking here about ordinary, everyday coughing—coughing that accompanies an ordinary upper respiratory infection (the common cold.) If someone is coughing because of asthma or pneumonia or croup or something like that, there’s specific therapy that ought to be given. Most coughs, though, are just coughs. And we want them to go away.
What’s available to help with coughing? Humid air from a vaporizer might help some (though some studies show warm humidity might worsen allergic coughs). At least one study showed that menthol rubs (like “Vicks VapoRub”) help, though the study itself wasn’t strong. We know that cough and cold medications commonly sold over the counter not only don’t work, but aren’t particularly safe. There are also dozens (maybe hundreds) of alt-med herby things that are sold, again with no evidence whatsoever that they work. Bottom line: we don’t have much for coughing.
One idea: honey. Honey is effective in children—two studies in 2007 and 2010 have shown it’s more effective than cough “medicine”—but can’t be used before the first birthday. It’s safe (at least past 12 months of age), it’s cheap, it’s worth a try. But what to do with coughing children less than one?
The same researchers who did the 2007 honey study just published another report, looking this time at agave syrup for cough in children 2 months to 4 years old. Agave syrup is a sweet extract from a cactus. It’s thick, like honey, and tastes good—and at least in reasonably small doses it’s safe at any age. In this study, a total of 69 babies and children with ordinary cough were randomized into three groups. One group got a small dose of agave syrup, one group got a “placebo” dose of grape-flavored water, and the third group got no intervention at all. The next evening, parents filled out a report of their assessment of cough severity.
Their study showed that all three groups had an improvement in cough the night after the study—whether given agave, placebo, or nothing at all. Though all children improved, the ones given agave or placebo improved somewhat more. There were several measures of cough, but to give you an idea, looking at the aggregate “cough score,” the improvement was about 10 for children given nothing, and about 15 for children given agave or placebo.
What does all of this mean? Bottom line: coughing gets better, whatever you do. But if parents are given instructions to do something, whether it’s agave syrup or a placebo solution, the cough seems to get better by a little more. Agave “works”, but it only works as well as the placebo, which by usual convention means it doesn’t work at all. Nonetheless, the parents in the study perceived that children given something did a little better than children given nothing.
Agave syrup is probably as safe as doing nothing. If you want to try it, go ahead. But I’m a little leery of the idea of encouraging an intervention that’s no better than placebo. I don’t like to create a dependence on medical interventions, especially ones that aren’t necessary. Parents shouldn’t feel that every medical issue needs a medicine, or a trip to the pharmacy, or even a trip to the grocery store or the “placebos-r-us” boutique. Hugs and love and comfort aren’t going to be studied, but I suspect they’re often the best medicine of all.