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

This study aimed to assess whether adding flow restrictors, adapters added to the neck of a bottle to limit the release of liquid, affects the proportion of preschool-aged children who can access liquid bottle contents, the amount accessed, and the time required for children to empty the bottles compared with traditional bottles without flow restrictors.

Study Overview

• Status: Completed
• Conditions: Enhanced Child-safety Packaging
• Intervention / Treatment: Other: Bottle with a flow restrictor; Other: Control bottle

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Actual): 120
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: Yes

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Bottle with a flow restrictor; Bottle with 1 of 3 randomly assigned flow restrictor designs (FR-bottle)	Other: Bottle with a flow restrictor; Flow restrictors added to liquid medicine bottles to determine whether they limit accessibility of liquid bottle contents to young children compared with control bottles without flow restrictors.
Active Comparator: Control bottle; Traditional bottle either no cap or an incompletely-closed child-resistant cap	Other: Control bottle; Traditional bottle either no cap or an incompletely-closed child-resistant cap

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proportion of children who removed specified amounts of test liquid from FR-bottles compared with control bottles	Proportion of children who emptied bottles, removed ≥ 25 mL, and who removed ≥ 5 mL of liquid from FR-bottles compared with control bottles	0 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time required to empty the bottles	Proportion of children who emptied bottles, removed ≥ 25 mL, and who removed ≥ 5 mL of liquid from FR-bottles compared with control bottles	0 days
Proportion of liquid removed from bottles	Proportion of children who emptied bottles, removed ≥ 25 mL, and who removed ≥ 5 mL of liquid from FR-bottles compared with control bottles	0 days
Approaches used to remove liquid from bottles	Proportion of children who emptied bottles, removed ≥ 25 mL, and who removed ≥ 5 mL of liquid from FR-bottles compared with control bottles	0 days
Differences in proportions of children who removed specified amounts of liquid by age, sex, and site	Proportion of children who emptied bottles, removed ≥ 25 mL, and who removed ≥ 5 mL of liquid from FR-bottles compared with control bottles	0 days

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Amount of test liquid removed from individual FR-bottle designs	Proportion of children who emptied bottles, removed ≥ 25 mL, and who removed ≥ 5 mL of liquid from FR-bottles compared with control bottles	0 days

Collaborators and Investigators

• Sponsor: Centers for Disease Control and Prevention
• Collaborators: Emory University; Grady Health System
• Investigators: Principal Investigator: Daniel S Budnitz, MD, MPH, Centers for Disease Control and Prevention

Study record dates

Study Major Dates

• Study Start: April 1, 2012
• Primary Completion (Actual): May 1, 2012
• Study Completion (Actual): May 1, 2012

Study Registration Dates

• First Submitted: April 18, 2013
• First Submitted That Met QC Criteria: April 14, 2025
• First Posted (Actual): April 22, 2025

Study Record Updates

• Last Update Posted (Actual): April 22, 2025
• Last Update Submitted That Met QC Criteria: April 14, 2025
• Last Verified: April 1, 2025

More Information

Terms related to this study

• Keywords: Injury Prevention; Medication Safety; Child Injury; Child-resistant Packaging; Pediatric Poisoning
• Other Study ID Numbers: CDC-NCEZID-6162