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CDC study: Flow restrictors likely effective in reducing accidental overdose in children


CINCINNATI — In a study scheduled for publication in the Journal of Pediatrics, researchers found that adding flow restrictors to bottles can limit the amount of liquid medication a child could access even if child-resistant caps are missing or improperly closed. 

Standard child-resistant packaging is designed to prevent or delay young children from opening bottles, giving caregivers reasonable time to intervene. However, in order for the packaging to work effectively, "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," noted Daniel Budnitz and colleagues from the Centers for Disease Control and Prevention, Emory University and the Georgia Poison Center.

More than 60,000 young children end up in emergency departments every year because they got into medicines while their parent or caregiver was not looking, according to CDC statistics.

To address a potential second line of defense, the researchers studied whether flow restrictors (adapters added to the neck of a bottle to limit the release of liquid) had any effect on the ability of children to remove test liquid, as well as how much they were able to remove in a given amount of time. 

As many as 110 children, ages 3 years to 4 years, participated in two tests. In one test, the children were given an uncapped medication bottle with a flow restrictor, and in the other test, the children received either a traditional bottle without a cap or with an incompletely closed child-resistant cap. For each test, children were given 10 minutes to remove as much test liquid as possible.

Within two minutes, 96% of bottles without caps and 82% of bottles with incompletely closed caps were emptied. In contrast, none of the uncapped bottles with flow restrictors were emptied before six minutes, and only 6% of children were able to empty bottles with flow restrictors within the 10-minute test period. Overall, older children were more successful than younger children at removing liquid from the flow-resistant bottles. None of the youngest children (36 months to 41 months) were able to remove 5 mL of test liquid, the amount in a standard dose of acetaminophen for a 2- to 3-year-old child.

“The CDC’s study published today shows that the new flow restrictors used on the pediatric single-ingredient acetaminophen may help prevent harmful exposure should a young child get ahold of the medicine while unsupervised," the Consumer Healthcare Products Association noted in a statement. "CHPA and its member companies will continue to monitor the real-world impact of the new flow restrictors and other liquid acetaminophen product initiatives and will continue to support CDCs and others’ research in this area. As we learn more, we will use the data to inform our ongoing effort to help families use over-the-counter products safely and appropriately. 

Manufacturers voluntarily added flow restrictors to over-the-counter infant acetaminophen in 2011. Based on their effectiveness, the authors suggest that flow restrictors could be added to other liquid medications, especially those harmful in small doses. "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," wrote Maribeth Lovegrove, co-author of the study.

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