Traditional medical treatment of persistent cough may not be the most effective

Oct 23 2005

Two new reviews of previous medical studies suggest that traditional medical treatment of persistent cough may not be the most effective.

One review concludes that antibiotic treatment might be useful for children with moist coughs that last more ten days. A second review suggests that children with persistent dry coughs should not be treated with corticosteroid drugs normally prescribed for asthma patients.

However, each review included only two studies with a relatively small number of patients, making it difficult to say definitively whether these treatments are the best option for most patients, say the authors.

The reviews appear in the current issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates medical research. Systematic reviews draw evidence-based conclusions about medical practice after considering both the content and quality of existing medical trials on a topic.

In their review of moist cough -- coughs that sound as if there is mucus in the throat or lungs -- Julie Marchant, M.D., of the Royal Children's Hospital in Brisbane, Australia, and colleagues found that a week-long course of antibiotics resulted in the cough's disappearance in one of every three children treated. The antibiotics kept the cough from becoming worse in one of every four children treated.

Another earlier study conducted by Marchant suggests that bacterial bronchitis is common in children with this type of persistent cough, and "this may explain the findings of this review that antibiotics appear to be beneficial for prolonged moist cough in children," Marchant says.

"The use of antibiotics however has to be balanced against their well-known adverse events," such as allergic reactions and overuse of the drugs that can lead to antibiotic resistance, she adds.

Marchant and colleagues analyzed two studies comparing antibiotic treatment and placebo in 140 children age seven and younger with moist coughs lasting longer than 10 days. The studies were conducted in Sweden.

In the second Cochrane review, Dr. Ahmed Tomerak of Queen's Medical Centre in Nottingham, England, and colleagues analyzed two studies of 123 children ages 17 and younger with persistent dry cough who were treated with inhaled corticosteroid drugs.

Inhaled steroids are often prescribed for children with prolonged dry cough as a "test" to determine whether their cough might be caused by asthma, Tomerak says.

Children in the studies received varying doses of corticosteroids for two to five weeks. Tomerak and colleagues concluded that "there is currently no good evidence to suggest that treatment with standard doses of inhaled corticosteroids will be beneficial" for children with this type of dry cough.

Children who received high doses of the drugs at the start of their therapy did show signs of significant improvement in their cough, but placebo treatment also significantly reduced cough among the patients, the reviewers found.

The findings suggest that trial doses of asthma medications are not always appropriate for children with persistent cough, according to Tomerak and colleagues. The review could "save these children from the use of unnecessary medications and their associated side effects. It would also save their parents from any unnecessary expense," Tomerak said.

Tomerak said that "one great difficulty" in studying cough therapies in children is that coughs often get better on their own, without any medication. The coincidence can fuel the false impression that a particular treatment is effective, he says.

Michael Light, M.D., chair of the American Academy of Pediatrics study section on pediatric pulmonology, agrees. "The bottom line is that this is not uncommon for [cough] to happen in children. It's a self-limiting, benign condition for the most part."

The fact that child cough usually resolves itself with few serious complications may be one reason why there are so few studies that compare different treatments for the condition, Light added.

The Marchant review was supported by the Australian Cochrane Airways Group Scholarship and the Royal Children's Hospital Foundation in Brisbane.