Fentanyl-mixed and substituted heroin is well-documented, but less is known about unintentional fentanyl use among people using stimulants. To determine the prevalence of and racial and ethnic disparities in unintentional fentanyl use among people experiencing a medically attended opioid overdose, we reviewed 448 suspected non-fatal overdose cases attended by a community paramedic overdose response team in San Francisco from June to September 2022. We applied a case definition for opioid overdose to paramedic records and abstracted data on intended substance use prior to overdose. Among events meeting case criteria with data on intended substance use, intentional opioid use was reported by 57.3%, 98.0% of whom intended to use fentanyl. No intentional opioid use was reported by 42.7%, with most intending to use stimulants (72.6%), including methamphetamine and cocaine. No intentional opioid use was reported by 58.5% of Black, 52.4% of Latinx, and 28.8% of White individuals (p = 0.021), and by 57.6% of women and 39.5% of men (p = 0.061). These findings suggest that unintentional fentanyl use among people without opioid tolerance may cause a significant proportion of opioid overdoses in San Francisco. While intentional fentanyl use might be underreported, the magnitude of self-reported unintentional use merits further investigation to confirm this phenomenon, explore mechanisms of use and disparities by race and ethnicity, and deploy targeted overdose prevention interventions.

芬太尼混合和替代海洛因已有充分记录，但对于使用兴奋剂的人无意中使用芬太尼的情况知之甚少。为了确定阿片类药物过量就医的人群中无意使用芬太尼的流行率以及种族和民族差异，我们回顾了 2022 年 6 月至 9 月期间由旧金山社区护理人员过量反应小组处理的 448 例疑似非致命过量用药病例。将阿片类药物过量的病例定义应用到护理人员记录中，并提取有关过量服用前预期药物使用的数据。在符合病例标准并具有预期物质使用数据的事件中，57.3% 报告有意使用阿片类药物，其中 98.0% 打算使用芬太尼。 42.7% 的人报告没有有意使用阿片类药物，大多数人打算使用兴奋剂 (72.6%)，包括甲基苯丙胺和可卡因。 58.5% 的黑人、52.4% 的拉丁裔和 28.8% 的白人（p  = 0.021）以及 57.6% 的女性和 39.5% 的男性（p  = 0.061）报告没有故意使用阿片类药物。这些发现表明，在旧金山，无阿片类药物耐受性的人群无意中使用芬太尼可能导致阿片类药物过量服用的比例很大。虽然有意使用芬太尼的情况可能被低估，但自我报告的无意使用芬太尼的严重程度值得进一步调查，以证实这一现象，探索使用机制和种族和民族差异，并部署有针对性的过量预防干预措施。