Flow Restrictors May Help Prevent Pediatric Poisonings

Children were much less successful at extracting liquid from medicine bottles equipped with flow restrictors than from poorly closed traditional medicine bottles.

Adding flow restrictors to liquid medicine bottles may help prevent young children from unintentionally ingesting medications, even when child-safety caps are not fully closed, according to the results of a study published online on July 9, 2013, in the Journal of Pediatrics.

Traditional child-resistant medicine caps are only effective in preventing unsupervised children from ingesting medications if adult users close the top correctly after each use. Flow restrictors, which were added to infant acetaminophen in 2011, are rubber stoppers attached to the neck of a medicine bottle to limit the release of liquid, requiring use of a syringe to access the medication. To test whether flow restrictors prevent accidental ingestions, even when medicines are left open or partially opened, researchers conducted a randomized trial of 110 children aged 3 to 4.

The participants took part in 2 consecutive trials in which they were given a test bottle filled with strawberry syrup and were encouraged to remove all of the liquid. For the first trial, the children were given an uncapped bottle with a flow restrictor and syringe. Three different types of flow restrictor currently in use were tested. For the second trial, children were given a traditional bottle without a cap or with an incompletely closed child-safety cap and a dosing cup. If a child did not empty the bottle after 5 minutes, the researchers removed the liquid in front of them, simulating what the child might observe at home. They then reminded the child that they could use their teeth and gave the child an additional 5 minutes to attempt to remove the liquid. After both trials, the children were instructed on medication safety.

The results indicated that children had little trouble accessing medications from the poorly closed traditional bottles. Of the children given traditional bottles without caps, all but 1 (96%) managed to empty the bottles within 2 minutes, and 82% of children given bottles with incompletely closed caps removed the liquid within 2 minutes. However, no child was able to empty a flow restrictor bottle in less than 6 minutes, and only 6% were able to empty one during the full 10 minutes. All children assigned open bottles and 90% of those given incompletely closed bottles removed at least 25 mL of liquid, the equivalent of 5 doses, most of them doing so in less than 5 minutes. By contrast, just 11% of the children were able to remove 25 mL of liquid from bottles with flow restrictors, and only 1 child did so during the first 5 minutes. More children—19%—were able to remove at least 5mL, or 1 dose, from the bottles with flow restrictors, but only 4 children (4%) did so within 5 minutes. Older children were more successful than younger children at emptying the bottles, and none of the youngest children were able to remove even a single dose from the bottles with flow restrictors. All children who removed at least 25 mL of liquid from bottles with flow restrictors used the syringe.

Compared with open bottles and bottles with incorrectly closed caps, bottles equipped with flow restrictors decreased the number of children who accessed the liquid and decreased the amount of liquid accessed while increasing the amount of time the children needed to empty the bottle. The researchers note that this delay may give adults more time to intervene before children are able to ingest harmful amounts of medication. The effects of flow restrictors may be even greater than the results show, the researchers suggest, as many children in a home environment may stop trying to access medications without the encouragement given to them throughout the trial. However, the researchers emphasize that flow restrictors are meant as a secondary barrier against unintentional medication ingestions and caution against relying on them alone.

“Although improved packaging can limit ingestions, educational interventions should continue to highlight the importance of locking child-resistant caps after each use and storing medicines up and away, and out of sight of young children,” the researchers write.