More trials needed to assess pain drug safety in children

May 20, 2011

Can we be certain that pain medications considered safe for adults, based on extensive clinical data and experience, are equally safe for use in young children? Pediatric pain experts discussed this question today in a panel session at the American Pain Society (APS) annual scientific meeting and agreed more short- and long-term clinical data are needed to provide assurances about the safety and efficacy of several pain medications in children.

“The overwhelming majority of pain drugs used in children are prescribed off label and clinicians have limited reliable data from which to guide their prescribing,” said Gary Walco PhD, director of pain medicine, Seattle Children’s Hospital and professor of anesthesiology, University of Washington.

“Extrapolating from adult clinical data has been the norm, but that doesn’t provide assurances that opioids and other potent pain drugs are safe or effective, especially in young children.”

Walco said a key concern is the potential long-term consequences of chronic pain medication usage among infants and young children undergoing intensive care when children’s bodies and internal organs are still developing. Further, there are differences in how drugs act and are tolerated in neonates, infants, young children, and adolescents. “In adults and children, there are differences in drug metabolism, organ function, and in body size and weight. For example, there is tremendous variability in liver maturation during early infancy, which results in large variability in how drugs such as morphine are metabolized,” he said. “Also, we don’t how use of pain medications early in childhood, especially with repeated administration, can impact developing neurological systems.”

In 2009, a consensus conference was held involving FDA officials and pediatric pain experts to examine issues and limitations that should be addressed to remove obstacles to performing more clinical trials in pediatric populations. Recommendations from the conference have been provisionally accepted for publication. Earlier this month, the Pediatric Ethics Subcommittee of the FDA’s Pediatric Advisory Committee discussed if it is ethical to administer smaller than normal doses of investigational drugs as part of FDA reviews. The group concluded it is ethical in most cases.

Walco emphasized that ethical issues remain a key concern for enrolling children in drug trials, noting the ethical need to build scientific knowledge about the effects of medical products in children is balanced by the need to protect children from harm. “The operative principal governing pediatric testing is that children should participate in a trial where there is immediate benefit as well as knowledge gleaned that will help children in general,” he said. “Further, a child should have no additional burden for participation in research, especially having to endure even slightly undertreated pain.”

According to the Committee for Proprietary Medicinal Products, the first priorities for pediatric testing should be for medicines to treat diseases that occur exclusively in children and also for diseases found mainly in children. However, there also is a need to study more thoroughly the efficacy and toxicity in children of drugs used for treating diseases that afflict both children and adults.

A step in the right direction, according to Walco, is a provision in the Best Pharmaceuticals for Children Act, passed in 2007 as part of the FDA Modernization Act, which provides incentive to pharmaceutical manufacturers to conduct pediatric trials for their products by granting an additional 6 months of patent exclusivity. As a result, many drugs have received pediatric labeling under this legislation.

“For years, children have been neglected in pharmaceutical research and it no longer should be acceptable to use powerful medications in children based on generalizations from treatment of adults,” said Walco. “Therefore, it is imperative that more pediatric data be generated in clinical trials for new and existing pharmaceutical products.”

Source: News Release
American Pain Society
May 20, 2011