Efficacy of Flow Restrictors in Limiting Access of Liquid Medicines by Young Children

Unsupervised ingestion of medications by young children is an important public health concern, leading to tens of thousands of emergency department visits and many more calls to poison control centers each year. Current knowledge on the specific circumstances in which young children gain access to medications is limited; however, a number of studies have shown that improper replacement of child-resistant packaging (CRP) by a caregiver leads to a substantial number of these incidents. Beginning in 2011, several pharmaceutical manufacturers introduced flow restrictors on over-the-counter (OTC) infants' acetaminophen; however, the efficacy of flow restrictors in limiting accessibility of liquid medicines by young children has not been formally assessed.

This study sought to determine whether adding flow restrictors, adapters added to the neck of a bottle to limit the release of liquid, to liquid medicine bottles can provide additional protection against unsupervised medicine ingestions by young children. A modified version of the standard child test protocol for re-closeable packages outlined in the Poison Prevention Packaging Act (PPPA protocol) was used to assess the efficacy of flow restrictors in limiting children's access to liquid medicines. Preschool-aged children participated in two 10-minute trials in which they were asked to try to "get everything out" of bottles filled with test liquid (a food product with similar flow characteristics to liquid medicine). Randomized block design was used to assign specific bottles to participants. Each child tested an uncapped bottle with a flow restrictor (FR-bottle) for one trial (1 of 3 designs randomly assigned). For the other trial, the child tested a control bottle (a traditional bottle either no cap or an incompletely-closed child-resistant cap). The amount of liquid the child removed from each bottle was measured and the time required to empty bottles was recorded. If flow restrictors limit the amount of liquid a young child can access, even when the outer child-resistant cap is not fully secured, their use could potentially be expanded to other liquid medicines.

Inclusion criteria

• Attends one of the participating preschools
• Is between 36 - 59 months of age
• Is an English speaker

Exclusion criteria

• Has an obvious or overt, temporary or permanent, injury, illness, or physical or mental disability
• Has known allergies/restrictions to ingesting any ingredients in the test liquid