Trends in the Concurrent Use of Illicit Drugs and Interacting Medications Among Adults in the United States

Abstract Introduction: The concurrent use of illicit drugs and prescription medications with potential drug-drug interactions (DDIs) significantly increases the risk of adverse events, including unintentional overdose. This study investigates trends in the concurrent use of illicit drugs such as cannabis, heroin, cocaine, and methamphetamine (HCM) and interacting prescription medications among U.S. adults from 2013 to 2018. Methods: Data were collected from the National Health and Nutrition Examination Survey (NHANES) for adults aged 18-59 years (N=10,321). Concurrent use was defined as the use of at least one illicit drug with one interacting prescription medication within the prior 30 days. Micromedex was used to identify medications having a contraindicated, major or moderate drug-drug interaction with illicit drugs. Result: The prevalence of concurrent use of illicit drugs and prescription medications increased from 5.1% to 9.8% between 2013 and 2018 (P=0.004). The concurrent use of illicit drugs with at least one interacting medication did not significantly change during this period and affected 3.1% of US adults in 2017-2018. Nearly one in five (18.4% [95% CI, 15.6%-21.6%]) adults that use cannabis and one in four (26.6% [95% CI, 19.4%-35.4%]) adults that use HCM used at least one interacting medication. Central nervous system depressants were the most common interacting medication among adults that used cannabis. Antidepressants, proton pump inhibitors, and opioid analgesics were the most common among adults that used HCM. Discussion and Conclusion: The rising trend in the concurrent use of illicit drugs and interacting medications poses a significant risk for overdose. More than 1 in 30 US adults, aged 18-59 years, concurrently used either cannabis or HCM with an interacting medication is at risk of a unintentional drug overdose. National efforts to improve the safe use of prescriptions among people that use illicit drugs should address potential drug-drug interactions.