Efficacy of flow restrictors in limiting access of liquid medications by young children

J Pediatr. 2013 Oct;163(4):1134-9.e1. doi: 10.1016/j.jpeds.2013.05.045. Epub 2013 Jul 26.


Objective: To assess whether adding flow restrictors (FRs) to liquid medicine bottles can provide additional protection against unsupervised medication ingestions by young children, even when the child-resistant closure is not fully secured.

Study design: In April and May 2012, we conducted a block randomized trial with a convenience sample of 110 3- and 4-year-old children from 5 local preschools. Participants attempted to remove test liquid from an uncapped bottle with an FR and a control bottle without an FR (with either no cap or an incompletely closed cap).

Results: All but 1 (96%; 25 of 26) of the open control bottles and 82% (68 of 83) of the incompletely closed control bottles were emptied within 2 minutes. Only 6% (7 of 110) of the bottles with FRs were emptied during the 10-minute testing period, none before 6 minutes. Overall, children removed less liquid from the bottles with FRs than from the open or incompletely closed control bottles without FRs (both P < .001). All children assigned open control bottles and 90% of those assigned incompletely closed control bottles removed ≥ 25 mL of liquid. In contrast, 11% of children removed ≥ 25 mL of liquid from uncapped bottles with FRs. Older children (aged 54-59 months) were more successful than younger children at removing ≥ 25 mL of liquid (P = .002) from bottles with FRs.

Conclusion: Our findings suggest that adding FRs to liquid medicine bottles limits the accessibility of their contents to young children and could complement the safety provided by current child-resistant packaging.

Keywords: CDC; Centers for Disease Control and Prevention; ED; Emergency department; FR; Flow restrictor; OTC; Over-the-counter; PPPA; Poison Prevention Packaging Act.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Child
  • Child, Preschool
  • Consumer Product Safety
  • Drug Packaging*
  • Equipment Design
  • Female
  • Humans
  • Male
  • Patient Safety*
  • Pharmaceutical Preparations / administration & dosage*
  • Poisoning / prevention & control*


  • Pharmaceutical Preparations