The findings, reported onlinein Paediatrics, come from a meta-analysis of 12 trials that tested the medications for treating gastro-oesophageal reflux disease (GERD) in infants, children or teenagers.
They found no good evidence that the drugs eased acid-reflux symptoms in infants - such as crying and "fussing" after being fed.
For older kids, there was better evidence of a benefit, but very little data on the long-term effectiveness and safety of proton-pump inhibitors for children's GERD, the researchers say.
That does not mean a child should never take one of these drugs, said lead researcher Dr Rachel J. van der Pol, of Emma Children's Hospital in Amsterdam.
In individual infants and children, they can be justified, she said.
Proton-pump inhibitors are one of the common treatments for childhood GERD, according to Dr Steven J. Czinn at the University of Maryland School of Medicine in Baltimore.
Caution against drawing
"I would caution against drawing conclusions from a review of 12 studies," he said.
Dr Czinn, who chairs the American College of Gastroenterology's Paediatric Gastrointestinal Committee and was not involved in the study, said that there is evidence that proton-pump inhibitors can help treat children with an inflamed oesophagus lining due to acid reflux.
He noted that the researchers found hundreds of studies on paediatric GERD treatment, but only a dozen fit their criteria - that is, being a randomised controlled trial.
According to Dr Czinn, that highlights a big obstacle in paediatrics in general: In the case of most medications, there are few rigorously conducted trials involving children.
"This is a major issue for almost all medications in paediatrics," he said.
Ethics of trials with children
Many question the ethics of doing randomised controlled trials with children; and few parents seem willing to take the chance that their child will be assigned to a placebo instead of actual treatment.
Even among the 12 studies in the current review, few involved a placebo. All of the studies of older children either tested a proton-pump inhibitor against another heartburn medication, or they tested different doses of a proton-pump inhibitor against each other.
On average, children and teenagers did have improvements in their GERD symptoms. But they had similar improvements with proton-pump inhibitors and the comparison medications, and there were no clear differences with higher or lower doses.
In the studies in this review, the drugs were generally well-tolerated in the short-term, according to the researchers. The most common side effects included headache, stomach pain and diarrhoea.
One study of infants, though, found that babies treated with proton-pump inhibitors had a higher rate of lung infections.
Many babies and children with acid reflux can forgo medication altogether, both Dr van der Pol and Dr Czinn pointed out.
For infants, thickeners added to formula, or changes in feeding position, can work. For older children, changes like eating smaller meals or avoiding specific foods that trigger symptoms can be enough.
If those steps are not enough, there are medication options other than proton-pump inhibitors, such as histamine receptor blockers. However, Dr van der Pol pointed out, there isn't much evidence on the effectiveness of any medication for paediatric GERD. (Reuters Health/ March 2011)