Runny nose, congestion, sore throat, muscle aches, and cough . These infamous symptoms probably mean your child has a cold or the flu , two of the most common upper respiratory tract infections (URIs) in the United States. Compared with adults, children contract these infections more often—on average six times a year—and have more severe symptoms. Cough is considered the most disturbing symptom, as it is the second most common reason for visits to the pediatrician. Persistent cough can interfere with the much-needed sleep of a sick child, not to mention the child’s parent.

The vast majority of URIs are caused by viruses, which don’t respond to antibiotics. Therefore, parents often turn to over-the-counter (OTC) medications to help ease specific symptoms. The effectiveness of some OTC products is still up for debate. In fact, the American Academy of Pediatrics does not support the use of dextromethorphan (DM), a widely available cough suppressant, due to a lack of evidence of benefit and the possibility of adverse effects.

In a study published in the July 2004 issue of Pediatrics , researchers evaluated the effects of DM and the antihistamine diphenhydramine (DPH) on cough and sleep quality in children with URIs and found that these medications were no more effective than a placebo.

About the Study

Researchers from the Pennsylvania State College of Medicine recruited 100 children and their parents to take part in this two-day study. Children who visited their pediatricians with runny nose, cough, and other symptoms of a URI were invited into the study. Those chosen to participate had been sick for less than a week and had not yet taken medication to treat their symptoms. On day one, each parent answered five questions to describe his/her child’s symptoms the night before:

How frequent was your child’s cough?

How much did it affect your child’s ability to sleep?

How much did it affect your ability to sleep?

How severe was the cough?

How bothersome was the cough to your child?

For each question, the parent selected an answer along a 7-point scale, with responses ranging from “constant” or “extremely” to “not at all.”

The children were randomly assigned to take DM, DPH, or a placebo (a syrup with no active ingredients) that night. Parents, children, and researchers did not know which syrup was being taken. The next day, each parent completed the same survey again, which the researchers compared to the first.

The Findings

All of the scores—for DH, DPH, and placebo—improved significantly on day two as compared to day one. This means that all the child/parent pairs, regardless of whether they took a medication or a placebo, experienced a similar degree of improvement in symptoms and in sleep quality.

There was a slight, but not significant, tendency toward insomnia in children who took DM and drowsiness in children who took DPH.

How Does This Affect You?

This study shows that OTC medications containing DH and DPH do not confer any benefits over a plain syrup in easing a child’s cough and promoting sleep. However, these findings should reassure parents that a URI will resolve on its own, usually within several days.

Critics of the study might point out that the subjects received only one dose of the medication. It is possible that the results could be different if the syrups were given more often. However, these medications are not without their adverse effects, which the researchers caution should be seriously considered in light of their lack of benefit in this study.

While waiting for the URI to run its course, there are a few things that may ease your child’s discomfort:

Plenty of rest

Drinking fluids

Inhaling steam or mist from a vaporizer or hot shower to make secretions loose and easier to expel

Positive emotional attention