Child-resistant packaging for medications has undoubtedly prevented countless pediatric deaths, but is there room for improvement? Over 500,000 calls are still made to U.S. poison centers each year regarding the accidental ingestion of drugs, and the number of related visits to the emergency room is rising.

A new report from The Journal of Pediatrics suggests that flow restrictors could prevent a child's accidental exposure to liquid medicines. Flow restrictors are special rubber/plastic adapters that fit into the mouth of the bottle to help measure dosing.

Flow Restrictor designs.
"The adapters are added to the neck of a standard liquid medicine bottle to limit the release of liquid. The FR marked with an asterisk is no longer on the market; it has been improved to minimize the risk of pushing the FR into the bottle during syringe insertion." Credit: Lovegrove MC, Hon S, Geller RJ, et al. The Journal of Pediatrics. 2013.

2 Minutes To Empty

In 1970, Congress passed the Poison Prevention Packaging Act, which required child-resistant packaging for medicines and hazardous household products. According to data from the U.S. Consumer Product Safety Commission, child-poisoning fatalities have dropped significantly since then from 216 in 1972 to 34 in 2008. This amounts to an 82-percent decline.

For medicine bottles, this packaging is designed to keep children from removing the cap, but there is room for error.

"Caregivers must correctly resecure the cap after each and every use. If the cap is not correctly resecured, children can open and drink whatever medication is in the bottle," said lead author Dr. Daniel Budnitz of the Centers for Disease Control and Prevention (CDC) and his colleagues from Emory University and the Georgia Poison Center.

In this study, 110 children between the ages of three and four were recruited to test this possibility with liquid medicine bottles. The bottles didn't contain actual medicine, but a harmless fluid. In the first experiment, caps on these bottles were either left off or incompletely closed before being placed in front of the kids.

Within two minutes, 96 percent of the uncapped bottles and 82 percent of the incompletely closed bottles were completely emptied.

In contrast, children had a much tougher time emptying bottles with flow restrictors. Only six percent could do it within the 10-minute window allotted for the experiment. Older children in the study were better at this than younger kids.

"Of the 12 children who removed over 25 mL of liquid, 10 were from the oldest age group (aged 54-59 months)," wrote the authors.

In 2011, manufacturers began adding flow restrictors to infant medications that contain acetaminophen. Even a small overdose of the drug can cause fatal liver failure.

None of the youngest children in this study — 36 to 41 months — could removed over 5 mL of the test liquid, which is the standard dose for this age range.

This study suggests that flow restrictors could offer an additional means of protection from accidental drug exposure, so should they be incorporated into all liquid medicine bottles?

Last year, the drug maker Tylenol faced recalls after flow restrictors became dislodged, but the company has changed its design and maintains that they are safe when used correctly. See the video below:

Overall the authors feel that broader application of flow restrictors could be beneficial.

"Flow restrictors are designed as a secondary barrier and caregivers should not rely on flow restrictors alone; adding flow restrictors could complement the safety provided by current child-resistant packaging," concluded co-author Dr. Maribeth Lovegrove, of the U.S. CDC.

Source: Lovegrove MC, Hon S, Geller RJ, et al. Efficacy of Flow Restrictors in Limiting Access of Liquid Medications by Young Children. The Journal of Pediatrics. 2013.