What will cure your child's cough?

Continuing with the recent mini-theme of pharmaceutical agents going awry, it seems appropriate to revisit last week's FDA advisory that children under the age of 2 should not be given over-the-counter cough medicines. This advisory had been expected for several months, of course, and the companies involved had already pulled most of these products from the shelves voluntarily. The FDA has not yet resolved the question of what to do about cough medicines for children aged 2-11, but because of the risks of accidental medication and the existence of serious questions about the actual effectiveness of these medications, there is a substantial probability that the agency will decide to ban these as well. Of course, this would seem to leave parents in a bit of a bind: what will they turn to now that nasty-tasting cold medicines are gone?

Of course, the situation isn't that dire: after all, cold medicines do not cure colds: they merely treat symptoms. No cold medicine can actually diminish the length of time a child is sick. The main upshot of this decision will be to put more of a burden on parents, who will have to deal with illnesses using more traditional means. At the same time, I am reminded of a recent study indicating that traditional means might work just fine, at least in limited cases. In December, a report in Archives of Pediatrics and Adolescent Medicine stated that honey was more effective in easing cough symptoms in children aged 2-18 than the popular cough suppressant dextromethorphan (DM).

The study did not rely on objective measures of coughing frequency or intensity, but instead depended on the subjective reports of parents to determine the effects of the medicine. Children were treated with either honey-mimic DM (formulated to approximate the taste and consistency of honey), actual buckwheat honey, or nothing at all. While families receiving no treatment were not blind to this fact, the honey and DM treatment groups were blinded. Surveys filled in before and after treatment dictated who entered the trial and assessed the treatment results. The study involved a few more than 100 children from the Hershey PA area; the sample size was limited by the requirement that no cough medicine have been given to the child in the previous 24 hours.

The outcome is shown in the figure at right—higher scores on the survey reflect a worse condition (i.e. 6 = extremely frequent cough). "First night" reflects the pre-treatment condition, while "Second night" comes from the results of a telephone survey carried out after treatment. You'll notice right away that the claim honey is "better" than DM reflects a pretty narrow difference. For the most part, scores are not that different no matter what treatment was used. This is especially surprising in light of the fact that the "no treatment" option was not blind. One might reasonably expect that awareness of null treatment would produce a negative effect on the subjectively reported outcomes; however, this seems not to have happened. Still, there is a clear, if slight, advantage for the honey treatment in this study. At the same time, it does not appear that parents will be much worse off if they do nothing at all. Keeping in mind that cough suppressants only alleviate symptoms, and have no effect on the underlying infection, these results sharply call the benefits of DM treatments for children into question.

This is not actually as crazy as it sounds. As the authors explain, honey has well-known antioxidant and anti-microbial properties. The dark honey used in this study is likely to be even stronger in this regard. Also, the authors note that sweet placebos have often shown a comparable effect to DM, so physiological effects of the sugar may also play a role. Shelley Batts of Retrospectacle, who covered this study when it came out, suggests that the viscosity of honey may also have a role, as it "coats the throat".

There are some complaints to be made about the study: geographically and temporally it is rather limited, and factors such as income and nutrition seem to lack controls. DM might have benefits in children with poor nutrition or additional conditions that would not be picked up by this study. Moreover, the nature of the sample—cases of cough that were severe enough to cause a parent to visit the doctor but not severe enough to induce the parent to use an OTC medication—may be selecting for parents who overreact to a single bad night of an otherwise mild cough. Clearly a larger study with additional data-gathering and controls is desirable. The best situation would be to enroll families at the beginning of cold and flu season in a truly blind trial and track the coughs longitudinally. Also, "no treatment" should be replaced by something, perhaps a colored simple syrup, to preserve blindness, and a fourth group in which DM is mixed directly into honey should be added to assess the possibility that characteristics of the honey-mimic DM broke the blind. Cynically, one would also prefer that such a study not be funded by the honey board.

Despite these limitations, the results are quite striking. In light of this study and its own evolving but clear preference to err on the side of caution it is likely that the FDA will either ban children's cold medications or recommend significantly stricter labeling. This shift in attitude on the part of FDA may mark the beginning of a generalized swing away from medication and back towards traditional treatments for children with mild illnesses. However, the advent of the preference for medication did not arise from medication itself; rather it evolved in concert with social considerations such as the rise in families where both parents work. In the social context of the 21st century a prescription for "plenty of bed rest, lots of fluids, chicken soup, and honey for the cough", may not be as workable as it was 50 or even 20 years ago.

Paul IM, Beiler J, McMonagle A, Shaffer ML, Duda L, Berlin CM. "Effect of Honey, Dextromethorphan, and No Treatment on Nocturnal Cough and Sleep Quality for Coughing Children and Their Parents." Arch. Pediatr. Adolesc. Med. 161 (12) 2007 p. 1140-1146.