How do naloxone-based interventions work to reduce overdose deaths: a realist review

Area of Science:

• Public Health
• Pharmacology
• Sociology

Background:

• Naloxone is crucial for reversing opioid overdose, but its implementation effectiveness is context-dependent.
• Previous reviews confirm naloxone's efficacy but lack exploration of contextual factors and mechanisms.
• This realist systematic review investigates how context and mechanisms contribute to successful naloxone interventions.

Purpose of the Study:

• To develop a theory explaining the success of naloxone interventions.
• To identify key contextual factors and mechanisms influencing naloxone's effectiveness.
• To provide guidance for optimizing naloxone-based public health strategies.

Main Methods:

• Realist systematic review adhering to RAMESES standards.
• Inclusion of all study designs examining naloxone for opioid overdose.
• Data extraction based on 55 realist-derived outputs to identify middle-range theories.

Main Results:

• Harm reduction and low-threshold contexts foster helping norms and empower bystanders.
• Stigma and negative attitudes from stakeholders can create fear, hindering bystander response and naloxone use.
• Two middle-range theories emerged: Naloxone Bystander Intervention Theory and Skills Transfer Theory.

Conclusions:

• Harm reduction contexts are essential for successful naloxone intervention implementation.
• Peer-to-peer training models enhance social identity and skills transfer.
• Health systems should address stigma and promote low-threshold training to improve naloxone outcomes.