Inhalant Abuse and Dextromethorphan

Associations between discrimination and substance use among college students in the United States from 2015 to 2019

Discrimination has been associated with adverse health behaviors and outcomes, including substance use. Higher rates of substance use are reported among some marginalized groups, such as lesbian, gay, and bisexual populations, and have been partially attributed to discrimination. This study uses 2015-2019 National College Health Assessment data to determine whether college students reporting discrimination due to sexual orientation, race/ethnicity, gender, or age report greater substance use than their peers who do not report such experiences. Additionally, we assess exploratory questions regarding whether substance choices differ among students who reported facing discrimination. Over time, about 8.0% of students reported experiencing discrimination in the past year. After applying inverse probability treatment weights (IPTWs), exposure to discrimination was associated with an excess of 44 cases of marijuana use per 1000 students, an excess of 39 cases of alcohol use per 1000 students, and an excess of 11 cases of prescription painkiller use per 1000 students. Multivariable logistic regression models with IPTW demonstrated that students who experienced discrimination were more than twice as likely to use inhalants and methamphetamine. These students were also significantly more likely to use other drugs, including opiates, non-prescribed painkillers, marijuana, alcohol, hallucinogens, cocaine, and cigarettes; however, the differences with peers were smaller in magnitude. Students who experienced discrimination did not differ from peers who reported non-prescribed antidepressants use and were significantly less likely to use e-cigarettes and smokeless tobacco. Associations between discrimination and substance use vary by race, gender, sexual orientation, and age. These findings indicate that discrimination has significant associations with many kinds of substance use; however, the magnitude varies by substance type. More institutional efforts to address sources of discrimination affecting college students are needed.

Ten Years of Robotripping: Evidence of Tolerance to Dextromethorphan Hydrobromide in a Long-Term User

INTRODUCTION

Dextromethorphan hydrobromide is widely available as an over-the-counter cough suppressant. A semi-synthetic opioid displaying N-methyl-D-aspartate receptor antagonism, it is commonly abused for recreational purposes. Spuriously elevated serum chloride concentrations are a well-described phenomenon in the setting of dextromethorphan hydrobromide toxicity, but evidence to suggest the development of tolerance is limited to case reports.

CASE

A 32-year-old male known to chronically ingest dextromethorphan hydrobromide for recreational purposes presented to regional hospitals on 179 occasions over 110 months and was treated for dextromethorphan toxicity on 163/174 (93.7%) of these visits. He reported a subjective need to increase his dosing over time to achieve the same degree of intoxication. Measured serum chloride over this period (n = 217) ranged from 98 to 138 mEq/L (median 115 mEq/L, IQR 110-123 mEq/L). Measured concentrations over the 110-month period progressively rose, with a fitted plot of 111.15 + 0.00232x describing the rise in measured chloride. Though not formally assessed, anion gaps tended to become progressively more negative over the observed period.

DISCUSSION

We report a patient with persistent dextromethorphan hydrobromide abuse at escalating doses whose mean serum chloride concentration increased, on average, by 0.00232 mEq/L every day over a 110-month period. This case demonstrates progressive spurious hyperchloremia secondary to bromide interference in hospital-based chloride assays, supporting the patient's reported need to dose escalate to the same desired effect. Although this artefactual laboratory finding is a well-documented result of bromide ingestion, it may be useful in identifying patterns of dextromethorphan hydrobromide use that suggest tolerance.