It’s known that local drug markets influence what drugs are available to users and how users prepare and administer those drugs — which in turn impacts users’ risk behavior and health outcomes.

However, most studies on injection drug use in the United States have focused on persons who inject drugs (PWID) living on the East Coast. School of Public Health Assistant Professor Alexis Roth wants to bring more West Coast data into the mix.

Before joining Drexel, Roth worked at the University of California, San Diego. There, she conducted analyses that identified patterns of polydrug use among PWID living in that region. Polydrug use is when two or more drugs are used at the same time in combination or on the same occasion. She aimed to identify risk behavior and health outcomes associated with different patterns of polydrug use and to see how these patterns differed from those reported on the East Coast.

“The practice of polydrug use is poorly understood,” Roth says. “Often, PWID are labeled as either polydrug users or not. However, drugs can be combined either simultaneously (cocaine and heroine mixed together in a speedball) or sequentially (a shot of heroin to come down from a cocaine binge).”

Roth, along with researchers at San Diego State University; University of Nevada, Reno; University of Southern California; and University of California San Diego, analyzed data detailing weekly drug consumption over a period of six months among 551 PWID living along the border.

cross_cultures

On the East Coast, white powdered heroin and powder cocaine are common. On the West Coast, black tar heroin and methamphetamine dominate

Roth and colleagues identified two main drug-using classes: heroin injection and methamphetamine administered via multiple routes. Membership in each class was associated with differing odds of risk behavior and health outcomes. The make up of these classes was also different from those found on the East Coast.

The reason for these differences is a matter of supply, says Roth. On the East Coast, white powdered heroin and powder cocaine are common. While on the West Coast, black tar heroin and methamphetamine dominate.

Since joining Drexel, Roth has continued this work, developing a partnership with Prevention Point Philadelphia to explore polydrug use among clients using their syringe access program.

She hopes pilot data lead to a study that gathers drug use data on participants twice daily. Her goal is to obtain a more accurate picture of how/when drugs are being combined, why they are being combined, and how different combinations are associated with adverse health behavior (i.e., syringe sharing) or outcomes (i.e., accidental overdose).