Do OTC remedies relieve cough in acute URIs?
Two RCTs involving a total of 237 children compared antihistamines with placebo. One double-blinded trial reported that clemastine and chlorpheniramine were no more effective than placebo. The other partially double-blinded trial found that diphenhydramine didn’t decrease cough frequency more than placebo.
Two double-blinded RCTs (total of 155 children) showed that antihistamine-decongestant combinations (brompheniramine-phenylpropanolamine and brompheniramine-phenylephrine-propanolamine) didn’t reduce cough more than placebo. No studies have evaluated guai-fenesin in children.1
Honey appears to help
In a partially double-blinded RCT (the “no treatment” group was not blinded) of 105 children, a single dose of buckwheat honey decreased cough frequency, as assessed by parents, by 1.89 points on the 7-point Likert scale compared with DM (1.39) and no treatment (0.92; P<.001). Overall improvement in symptom score averaged 10.71 out of a total 30 points for honey compared with 6.41 for no treatment (P=.04). Cough frequency and overall symptom scores for DM didn’t differ significantly from no treatment. Hyperactivity, nervousness, and insomnia were reported more often with honey (5 patients) than DM (2 patients) or no treatment (0 patients); (P=.04).4
Placebos work, but why?
In a review of 8 RCTs, the average reduction in cough in the placebo group (both capsules and syrups) was approximately 85% of that seen in the active medication group (range 56%-105%).5 Several factors may account for the efficacy of placebo, including lubrication of the pharynx by increased salivation caused by sweet or bitter vehicles. Sweet vehicles also may stimulate endogenous opioids that may suppress cough. In an unblinded RCT of 54 patients, a capsule placebo significantly decreased the number of coughs during a 15-minute follow-up compared with no treatment (18 vs 3; P=.0003).6
Recommendations
The American College of Chest Physicians recommends a first-generation antihistamine-decongestant combination or naproxen for acute cough in the common cold (SOR: A). Newer-generation, nonsedating antihistamines are not recommended (SOR: D).7
The US Food and Drug Administration (FDA) advises against using OTC cough and cold medicines in children younger than 2 years because of the risk of “serious and potentially life-threatening side effects.” The FDA also recommends taking significant precautions if these products are used in children older than 2 years, pending a complete FDA review of the medications for children 2 to 11 years. Manufacturers of children’s cough and cold remedies have changed the labels on the medications voluntarily to recommend that they not be given to children younger than 4 years.8
The American Academy of Pediatrics recommends that physicians clearly educate parents about the potential risks and lack of benefits of DM- and codeine-containing cough remedies.9
