Opioid poisoning, also known as opioid overdose or opioid toxicity, is a medical emergency where there is excessive binding of opioids to mu-opioid receptors, leading to analgesia, sedation, and respiratory depression. Naloxone is currently the recommended treatment for reversing opioid poisoning
however, it has limitations, such as a shorter half-life than most opioids, which can lead to renarcotization. Multiple nanoparticle (NP) formulations have addressed this limitation by exhibiting a longer half-life as well as successfully antagonizing the effects of opioids. This review explores the polymer-, lipid-, and peptide-based NP formulations, which have been studied as alternatives for naloxone. NP-naloxone formulations have potential for implementation into clinical practice, yet their realization hinges on investment in research.