By: By Rachael Rettner, Senior Writer
Published: 12/09/2013 04:54 PM EST on LiveScience
Many medications commonly given to newborns still have not been officially approved for use in this very young population, despite recent law changes encouraging the study of drugs in children, a new study finds.
That means that drug labels often do not have information about the correct dose that should be used in newborns, and doctors instead must use their best guesses based on their experience and information from adults and older children, said study researcher Dr. Matthew Laughon, an associate professor in the Department of Pediatrics at University of North Carolina at Chapel Hill School of Medicine.
Drug studies in infants are challenging for a number of reasons — for example, a baby's small size prevents doctors from taking several samples of blood that would be needed to understand the effects of a drug. [7 Baby Myths Debunked]
But researchers must find a way around such obstacles, because such studies are critical to understanding how to most effectively use drugs in newborns, Laughon said. Children and babies have a unique physiology and will not necessarily respond to drugs the way adults do, Laughon said.
"As a society that cares about its premature babies and newborns, it's really incumbent on us to make these vulnerable children less vulnerable," by using effective drugs to treat birth complications, said Dr. Edward McCabe, chief medical officer of the March of Dimes, who was not involved in the study.
Drugs in newborns
Recent laws have attempted to improve the study of drugs in children in order to add child-specific safety and dosing information to drug labels, including a 1997 law that provided incentives to drug companies for conducting such studies.
As a result, an increasing number of drugs have had their labels changed to include child-specific information, but the new study finds that for newborns (infants who are 28 days or younger), most drug labels are still lacking.
Between 1997 and 2010, 406 drug labels were changed to included child-specific information, but just 24 of these changes (6 percent) mentioned how the drug should be used in newborns, the study found.
What's more, 13 of the 24 labeling changes related to newborns (54 percent) said that the drugs had not been found to be safe and effective in newborns, but many of these drugs were still used in this population.
On the other hand, drugs that were found to be safe and effective in newborns were often indicated for rare conditions, such as HIV (which is rare in newborns in the United States), and these drugs were not commonly used in Neonatal Intensive Care Unit (NICU), Laughon said.
The study is published in the Dec. 9 issue of the journal JAMA Pediatrics.
Sometimes, doctors have no choice but to use drugs off-label (without specific approval for newborns), Laughon said. "For some things, like infections, you have to do something … you've got to use your best guess," Laughon said. Laughon noted that the antibiotic ampicillin is one of the most commonly used drugs in newborns, yet dosing information for infants is still being studied.
But in cases that are not life-threatening, doctors should limit the use of drugs for which there is very little evidence of effectiveness for newborns, Laughon said. For example, the drug ranitidine is a commonly used drug to treat gastroesophageal reflux disease in newborns, even though studies have not found the drug to be effective for this purpose, Laughon said.
McCabe agreed. "If we were to not use drugs off-label [in newborns], then there would be almost nothing to use," McCabe said. But if a clinical trial shows that a drug is not beneficial for newborns, "then the drugs should not be used for that indication," McCabe said.
Because newborns are such a difficult population to study, more specific incentives may be needed to increase drug studies in this population, McCabe said. For example, the 1997 law gave drug companies an extra 6 months on their patent if they studied their drug in children, but this does not provide an incentive to study newborns specifically, McCabe said.
A collaboration called the Pediatric Trials Network is also collecting information about drugs already been used off-label in infants to increase researchers' understanding of these drugs.