At first, the cluster of deadly overdoses reviewed by the Hennepin County medical examiner's office this winter gave no indication that a new opioid hitting the streets was instantly killing its users.
The victims each showed telltale signs of drug abuse, but their autopsy tests came back negative for the most commonly abused substances.
Nearly two months after the first reported overdose in late January, medical investigators were stunned to learn that the drug carfentanil — used to tranquilize elephants — could be responsible for at least nine other deaths. The Drug Enforcement Administration went public with the discovery 30 hours after it learned of the results.
Carfentanil, a white powder that looks similar to other opioids, can't be diluted enough to make it safe for humans, said Ken Solek, the DEA's assistant special agent in charge in Minnesota. Little medical research exists on the drug, but Solek described it as "fentanyl on steroids" — and 10,000 times more potent than morphine.
Ingesting just two salt-sized grains of carfentanil can mean instant death, officials warn.
State and federal law enforcement agents are bracing for more carfentanil overdoses by cobbling together a multipronged response and prevention plan. The strategy includes intense education efforts, stronger synthetic drug legislation and ongoing diplomatic talks with China, the main source for carfentanil.
"If dealers had any ethics and morals, they would stop lacing this substance with other drugs. But they don't care about anybody," said Apple Valley Police Chief Jon Rechtzigel, who had an overdose in his city.
A new scourge
The first verified overdose of carfentanil in the United States occurred last July in Akron, Ohio, where several dozen people died during a three-week period. The DEA made more than 400 seizures of carfentanil across eight states from July through October.