Introduction and Aims: Despite the potential harms of mixing unregulated drugs with energy drinks (ED), research to date has primarily been focused on EDs co-ingested with alcohol. Consequently, the aim of the present study was to explore the rate of use, harms and correlates of EDs co-ingested with alcohol and other drugs among a sample of people who regularly use illicit stimulant drugs.

Design and Methods: In 2010, 693 Australians who regularly used ecstasy completed a 1-h interview about their past six-month ED and drug use.

Results: Three-quarters of the sample (77%) had recently consumed EDs with other substances, primarily alcohol (70%) and ecstasy (57%). People who consumed ED with alcohol versus those who had consumed ED with ecstasy and with alcohol (only 8% reported only consuming ED with ecstasy) had similar profiles in regards to demographics, drug use, mental health and drug-related problems. Primary motives for consuming ED with alcohol included increased alertness (59%), the taste (25%), to party for longer (23%) and to combat fatigue (16%). One-half (52%) and one-quarter (27%) of participants who consumed EDs with alcohol and with ecstasy respectively had recently experienced adverse outcomes post-consumption, primarily headaches (24% and 11%) and heart palpitations (21% and 14%).

Discussion and Conclusions: Co-ingestion of EDs with licit and illicit drugs is common among people who regularly use ecstasy and related drugs. Adverse outcomes of co-ingestion suggest that targeted education regarding negative interactive drug effects is crucial for harm reduction.