The number of people dying of drug overdoses in Orange County has soared to the highest levels in at least a decade.

According to preliminary coroner data, fatal drug overdoses climbed to at least 400 last year, a 6 percent increase from 2014 – and a nearly 63 percent jump compared with 2005, when the number stood at 246.

The latest figures punctuate a problem that has rapidly multiplied in Orange County and the U.S. In the past five years, drug overdoses have killed 1,769 people in the county.

The coroner’s office has cases awaiting toxicology results, so the 400 figure could rise.

More than two-thirds of last year’s cases – 286 – involved opioids, a class of drug that includes heroin and prescription painkillers such as Percocet, OxyContin and Vicodin.

That’s not unusual: A 2014 report from the county Health Care Agency found that from 2011 to 2013, 70 percent of all drug and alcohol overdose deaths investigated by the coroner involved opioids.

The Centers for Disease Control and Prevention considers the spike in opioid abuse and death a national epidemic, claiming 78 lives daily in the U.S.

“Frankly, we’re still under-resourced. I think the public doesn’t fully appreciate yet the scope of the problem,” President Barack Obama said in March at the National Rx Drug Abuse & Heroin Summit in Atlanta, where his administration announced it would spend $11 million to expand access to naloxone, a fast-acting opioid overdose-reversal medicine.

Obama also is asking Congress to spend an extra $1.1 billion to expand treatment and programs to prevent prescription drug and heroin overdoses.

It’s been only within the past few months that such efforts have escalated to curb the death toll.

“We have a community at risk,” said Dr. Padma Gulur, a pain specialist at UC Irvine Health. “It’s so concerning.”

Gulur is leading a new coalition of health insurance companies, law enforcement agencies, hospitals and public health agencies that has collected drug overdose data from 2013 on every California county.

The numbers show Orange County has one of the higher rates of prescription opioid deaths in the state, 17th out of 58 counties.

The coalition is encouraging physicians to scale back the amount of opioids they prescribe and to know the signs of addiction. It’s also coming up with ways to expand access to naloxone.

“Naloxone saves lives; it just does,” Gulur sad. “Looking at the data from the coroner’s office, these are preventable deaths.”

Two local mothers whose children died of overdoses are on a mission to distribute naloxone, also known under the brand name Narcan. It can be sprayed into the nose or jabbed into arm or leg muscles to kick-start the lungs of someone who has stopped breathing after overdosing on opioids.

The mothers, Aimee Dunkle and Margie Fleitman, are taking the antidote to sober-living homes and putting it in the hands of users and their families.

The mothers also are working with UCI medical students who in February won approval from the state health department to hand out clean needles to users on Saturdays in downtown Santa Ana.

They’ve given out hundreds of vials of naloxone, and 48 clients have reported successfully using it to revive a person who overdosed, Orange County Needle Exchange Program founder Kyle Barbour said.

A proposal in the Legislature would take the needle exchange concept a step further by making it legal for local public health departments to set up clean, safe places for users to inject and ride out their highs under medical supervision.

Drug use via needles is so pervasive in Orange County that in 2½ months, Barbour’s group distributed 40,000 clean needles and collected 23,928 dirty ones – numbers they anticipated hitting over a full year.

“There’s a huge need – much greater than we initially expected,” he said.

But, he added, “As large as we feel our statistics are, there are surely people in Anaheim, Fullerton, Huntington Beach that need access to these services but can’t get to us or haven’t heard about us. That demonstrates the urgent need for more of these services.”

Contact the writer: jchandler@ocregister.com and @jennakchandler on Twitter