When Tyler Shamash survived a drug overdose at 19, his mother, Juli, asked his doctor several times if he’d been tested for fentanyl.

Tyler had been in and out of sober living homes in Los Angeles after battling addiction for years, and his family suspected he may have been taking illicit drugs. The doctor said they had run a standard drug test and fentanyl hadn’t come up in the toxicology screen.

Juli Shamash believes the doctor didn’t know that fentanyl isn’t included in the standard test run in emergency rooms across the country. A standard drug test panel in most emergency rooms checks only for marijuana, cocaine, amphetamines, PCP and natural and semi-synthetic opioids (like heroin and oxycodone) — but not synthetic opioids like fentanyl.