Even careful parents can be confused by the dosing instructions and measuring devices that come with many over-the-counter liquid medications, according to a new study published in the Journal of the American Medical Association. Researchers say the confusion could lead to over- or under- dosing with serious consequences, The Los Angeles Times reports.
In the study, researchers examined more than 200 popular liquid cough, cold, allergy and stomach medications, along with pain killers and fever reducers, recommended for children under age 12. They checked whether each medication had a measuring device such as a cup or eyedropper, and, if so, if the device was consistent with dosing instructions.
Researchers found that more than a quarter of the products lacked a measuring device. And nearly all that came with a measuring device, almost 99 percent, had at least one inconsistency between dosing instructions and the device.
For example, one of the medicines had instructions that called for one-teaspoon doses, but had a cup only marked in milliliters. Many measuring devices, in addition, had unnecessary markings, such as markings above a maximum dose.
Some medications also dropped the zero before decimal points– .5 instead of 0.5–which, the study’s author said, could lead to confusion that could cause a 10-fold overdose.
The U.S. Food and Drug Administration has made safe use of over-the-counter and prescription drugs a priority, the Times said, because studies have shown high error rates for both consumers and healthcare workers.
“We know people have trouble getting dosing right for not just over-the-counter but prescription liquid medication,” said Dr. Darren A. DeWalt, an associate professor of internal medicine and pediatrics at the University of North Carolina, Chapel Hill, who wrote an editorial accompanying the study. “But to see how common the mismatch was in this study was startling. It’s not only confusing information, it’s almost not intelligible at times.”
While dosing errors are rarely harmful, DeWalt said several days of overdosing with products that contain acetaminophen could lead to serious liver damage.
The study, led by a team at the New York University School of Medicine and Bellevue Hospital Center, was conducted before the FDA released voluntary guidelines in November, 2009, aimed at reducing dosing errors. The guidelines address several issues identified in the research but one of the study’s coauthors said that, given the scope of the problem, it was unlikely to be corrected through voluntary measures.
