STATEN ISLAND, N.Y. — Experts on Staten Island and nationwide are warning that drug traffickers are mixing potentially lethal fentanyl with veterinary sedatives — including one powerful enough to immobilize elephants.

Illicit fentanyl, an opioid that, by itself, is 50 to 100 times stronger than heroin, remains a factor in the majority of accidental drug overdoses on Staten Island, in New York City and throughout the United States. The synthetic opioid is potentially deadly at a mere 2 milligrams, an amount that fits on the head of a pencil.

Officials are warning about the growing use of veterinary drugs, often combined with fentanyl and other opioids.

Such combinations increase the chances of death and disability for users who range from children buying fake prescription pills on the da

See Full Page