New Study Examines Prescription Drug Dosage for Children

The Food and Drug Administration is responsible for regulating everything from vaccines to medical devices and food products. The FDA is also responsible for overseeing the safety of over-the-counter and prescription drugs through its Center for Drug Evaluation Research.

When the FDA approves medications, part of the process includes ensuring that the drugs are properly labeled for consumers. At times, however, medications approved by the FDA are prescribed by doctors for use in manners not contemplated by the agency or tested by the manufacturer. These uses are considered "off label." The FDA defines an off-label use as a "use for indication, dosage form, dose regimen, population or other use parameter not mentioned in the approved labeling."

Off label use is a widely accepted practice among doctors and supported by the American Medical Association. Researchers at Stanford University and the Institute of Medicine estimate that up to 20 percent of adult prescriptions are handled off label.

The concern of many doctors is prescription drug dosage for children handled off label, which an Institute of Medicine study says is done 50 to 75 percent of the time. But according to a report in The Wall Street Journal, "virtually all" drugs prescribed to children are done off label. This is mostly due to the fact that so few drugs are tested on the pediatric level. (One drug, Propulsid, which is used to treat severe heartburn, has killed 11 children.)

As a result, the National Institute of Health is funding a $95 million initiative in conjunction with the Pediatric Trials Network to study appropriate dosages for children and infants.

The study will be led by Danny Benjamin, a professor of pediatrics at Duke University's medical school, who tells The Wall Street Journal that the dosage prescribed to children off label is wrong about one-third of the time. According to Dr. Benjamin, a child's body weight is used to calculate the dosage, but that calculation does not take into account the way a child's body absorbs and metabolizes some medications.

Over the next seven years, the PTN will review dosages for different types of drugs. Drugs used to treat hypertension will be examined first, in part because the need is so great for obese children, as well as for those children who have had organ transplants, according to Dr. Benjamin.