Fentanyl mixed with cocaine or meth is driving the '4th wave' of the overdose crisis

The number of overdoses that involve both fentanyl and stimulants like cocaine and meth is growing fast. One way people who use drugs can protect themselves is by using test strips to check for the presence of fentanyl in other drugs. (Mark Lennihan/AP)

The mixture of stimulants like cocaine and meth with highly potent synthetic opioids is a fast-growing driver of fatal overdoses in the U.S.

Since 2010, overdoses involving both stimulants and fentanyl have increased 50-fold, and now account for 32% of U.S. overdoses in 2021 and nearly 35,000 deaths, according to a study published Thursday in the scientific journal Addiction.