This paper studies how opioid analgesic sales are related to socioeconomic conditions in France. Using the OpenHealth database on prescription opioid retail sales at the district level from 2008 to 2017, we show that increases in the poverty rate induce more sales: a one percentage point increase in poverty produces, approximately, a ten percent increase in opioid sales. Our analysis further shows that opioid sales are positively related to the share of middle-aged people and the share of individuals with basic education only, while they are negatively related to population density. We identify the causal effects of economic conditions on opioid sales by using two alternative strategies. First, we implement a Two-Stage Least Squares (2SLS) approach, where we instrument for poverty by exploiting a reform aimed at reducing poverty of low-income individuals. Second, we use a three-dimensional panel model that allows us to control for a large pool of potential confounding factors. We are among the first to address potential reverse causality issues in this context. Our results suggest that middle-aged individuals and people with lower education levels are mostly at risk and should be carefully screened before and monitored after being treated. Pharmaco vigilance should be more intensively addressed towards poor and rural areas. We conclude that a combination of policies aimed at improving economic prospects and strictly monitoring access to opioid medications would be beneficial for reducing opioid-related harm.