Critical changes in drug labeling for pediatric patients illustrate that unique pediatric dosing often is necessary, reflecting growth and maturational stages of pediatric patients, according to a study in the latest issue of Pediatrics.

And the researchers, led by William Rodriguez, the science director for the FDA’s Office of Pediatric Therapeutics, say these changes provide evidence that pediatric dosing should not be determined by simply applying weight-based calculations to the adult dose. Drug clearance, they emphasize, is highly variable in the pediatric population and is not readily predictable on the basis of adult information.

They reveiwed pediatric studies for 108 products submitted between July 1998 through October 2005 in response to an FDA written request for pediatric studies, and the subsequent labeling changes. Then, they write that they analyzed dosing modifications and focused on drug clearance as an important parameter influencing pediatric dosing. Of the 108 drugs with labeling changes, research yielded 23 with dosing changes or pharmacokinetic information; 34 had new safety info; 19 had info concerning lack of efficacy; 12 had new pediatric formulations, 77 had extended age limits (n = 77).

“Without appropriate safety and efficacy studies in children, pediatricians and other health professionals are often forced to treat children on a trial-and-error basis,” they wrote, adding that legislation encouraging pediatric testing has resulted in better dosing and side effect info in kids. Congress approved legislation twice since 1997 that provided market exclusivity to drugmakers that test their meds for kids.

This is the abstract.