Prepacked naloxone administration for suspected opioid overdose in the era of illicitly manufactured fentanyl: a retrospective study of regional poison center data.

Background: Prepacked naloxone kits (PNKs) are frequently used to reverse opioid intoxication. It is unknown if the presence of illicitly manufactured fentanyl and its analogs (IMFs) in heroin supply is affecting the PNK doses given by laypersons. We investigated the trend of PNK dose administered to reverse opioid toxicity in suspected/undifferentiated opioid intoxication. Methods: We retrospectively reviewed PNK administrations reported to the Maryland Poison Center between 1 January 2015 and 15 October 2017. Primary outcome was the mean PNK dose administered to reverse opioid-induced central nervous system and ventilatory depression. Secondary outcomes included the reversal rate of opioid toxicity, patient disposition, and survival rate. Results: Our analysis involved 1139 PNK administrations. The mean age of subjects was 34.3 years; 68.8% ( n  = 781) were male. Ventilatory depression was present in 98.2% ( n  = 958) of cases, and 97% ( n  = 1097) were unresponsive. Law enforcement administered the majority of PNK (91.0%; n  = 1035); the primary route was intranasal (97.9%; n  = 1051). Toxicity was reversed in 79.2% ( n  = 886) of overdose victims after a mean PNK dose of 3.12 mg. EMS personnel gave 291 subjects additional naloxone (mean: 2.2 mg), reversing opioid toxicity in 94.2% ( n  = 254). Between 2015 and 2017, the mean PNK dose increased from 2.12 to 3.63 mg ( p  < .0001) while the reversal rate decreased from 82.1% to 76.4% ( p  = .04). One hundred and eighty-two patients (15.9%) refused transport; of those transported to a hospital, 73.4% ( n  = 569) were treated and released and 12.4% ( n  = 96) required hospitalization. Ninety-six percent ( n  = 1092) of the subjects survived. Forty subjects were pronounced dead at the scene. Fentanyl or its analog was detected in 36 of 55 opioid-related deaths (65.5%). Conclusions: PNK administration reversed toxicity in the majority of patients with undifferentiated opioid intoxication. Between 2015 and 2017, increasing doses of PNK were administered but the reversal rate decreased. These trends are likely multifactorial, including increasing availability of IMFs.