An anesthetic commonly used for surgery has surpassed heroin to become the deadliest drug on Long Island, killing at least 220 people there in 2016, according to medical examiners’ records.

The drug, fentanyl, is a synthetic opioid, which can be 100 times more potent than morphine.

The numbers from Long Island are part of a national pattern, as fentanyl fatalities have already surpassed those from heroin in other parts of the country, including New England, as its use has skyrocketed. Part of the reason for the increase is economic — because fentanyl can be manufactured in the lab, it is much cheaper and easier than cultivating heroin.

In New York City, more than 1,000 people are expected to die from drug overdoses this year — the first recorded four-digit death total in city history, according to statistics compiled by the Department of Health and Mental Hygiene. Nearly half of all unintentional drug overdose deaths in the city since July have involved fentanyl, the health department said.

The medical examiners of Long Island’s two counties, Nassau and Suffolk, compiled the new numbers. “Fentanyl has surpassed heroin as the most commonly detected drug in fatal opioid overdoses,” Dr. Michael J. Caplan, the Suffolk County medical examiner, said in a written statement about the statistics, which were obtained by The New York Times ahead of their release. “The influx of illicitly manufactured fentanyl from overseas is a nationwide issue that requires a multidisciplinary intervention from all levels of government.”