In response to a spike in heroin overdoses that is believed to have killed at least seven people in the city so far this year, New Orleans is making a drug that counteracts the opiate’s effects available over the counter at University Medical Center.

City health officials are urging those who have family or friends who use heroin to keep a dose of Narcan, which reverses the effects of an overdose, on hand.

“There are no side effects. There is no abuse potential,” city Medical Director Dr. Joseph Kanter said Friday. “The primary effect of this medicine is to save a life.”

Under a standing order issued by Kanter, Narcan will be available to anyone at the University Medical Center Outpatient Pharmacy at 2000 Canal St.

That order was permitted under a law passed last year by the Legislature.

New Orleans Emergency Medical Services personnel use the drug to treat overdoses on emergency calls.

The need to use Narcan has risen sharply in recent weeks, officials said. Last year, ambulance crews used it on average about 2.5 times per day, but they are now treating patients at double that rate.

Overdose cases can be reported to EMS without fear of arrest under Louisiana laws.

The cases are coming so quickly that at one point, UMC had 14 overdose patients within a two-day span, Chief Medical Officer Dr. Peter DeBlieux said.

The overdose cases have been centered in the 7th Ward near North Claiborne Avenue and Elysian Fields Avenue and in the St. Roch and St. Claude neighborhoods on the river side of Claiborne, EMS Director Dr. Jeffrey Elder said.

Pharmacists at UMC will provide training to those who pick up the medicine, which costs between $30 and $50 per dose.

It’s not clear exactly what is causing the recent rash of heroin overdoses, which spiked in early January and have remained high since then.

Officials with the city’s Health Department and EMS said some people who are addicted to pain medicine may be switching to heroin because it is cheaper and easier to obtain than prescription medication. They also suggested some of the heroin now on the streets may be laced with other drugs, such as fentanyl, that may be contributing to overdoses.

Fentanyl is about 10 times as potent as heroin and costs about one-tenth as much to produce, Coroner Dr. Jeffrey Rouse said in a statement.

The seven deaths this month that are believed to be due to overdoses already amount to about one-eighth of the total number of heroin and fentanyl overdoses seen all of last year, Rouse said. The Coroner’s Office is still working to determine what drugs were in the systems of those who died from overdoses this year.

While saying he was grateful for laws that allow individuals and first responders to administer Narcan, Rouse also argued it would not completely mitigate the dangers of a combination of heroin and fentanyl.

“The likely re-emergence of fentanyl on the streets is particularly alarming,” Rouse said. “Fentanyl is incredibly potent. Users cannot tell if it has been used as an additive to heroin, and they can die so quickly that antidotes may be too late. In light of this killer, I urge the public to seek help for substance abuse before they have to pay me a visit.”

Follow Jeff Adelson on Twitter, @jadelson.