The report, by the U.S. Centers for Disease Control and Prevention, comes after the death of two men who had attended a Cow Palace rave over the Memorial Day weekend south of San Francisco.
The cases raised questions about whether publicly owned venues like the Sports Arena should host such events.
Pat Lynch, general manager for the arena and Los Angeles Memorial Coliseum said the arena and the organizers make efforts to arrest drug dealers and users.
"We do extensive searches when they come in.... We do our best to stop it all," he said. "You can't control what everybody does on their own." The Coliseum and Sports Arena are on state land and run under the authority of a joint city, county and state commission.
Lynch said he was aware of the 18 hospitalizations soon after New Year's Day but was unaware of the death until Thursday. He noted that the dead man, in addition to taking Ecstasy and cocaine at the Sports Arena, later injected himself with heroin when he got home.
"That's incredibly sad and unfortunate, but the fact is, he didn't die at the show," Lynch said.
Reza Gerami, founder of Go Ventures, which helped run the rave, said his company does not condone drug use.
"We run a very safe and organized event," Gerami said, while adding, "when you deal with the number of people that we deal with, you're always going to get a few bad apples."
Dr. Brian Johnston, emergency room medical director at White Memorial Medical Center just east of downtown, said that in the last couple of years he has noticed an increase in drug overdose cases during and after raves on Halloween and New Year's Eve.
The demand on the emergency-room system is so great that White Memorial is asked to handle the overflow of drug overdoses coming out of the Coliseum area, Johnston said. White Memorial's emergency room is not usually responsible for that neighborhood.
"I think these events are dangerous. That's my personal opinion," he said. "I think there's evidence people have been harmed … and I don't think we should be encouraging them in any way."
"These events were occurring on public property, which I thought was unconscionable," Johnston said.
The concern extends beyond L.A. The San Mateo County Board of Supervisors passed a resolution Tuesday asking the California Legislature to ban raves at the state-owned Cow Palace in Daly City.
"It's a magnet for drug dealers. You're putting our youth in harm's way," San Mateo County Supervisor Adrienne Tissier said.
At that rave authorities arrested more than 70 people on suspicion of drug dealing. At least nine other partygoers went to hospitals with suspected Ecstasy-related overdoses.
The report of the New Year's Eve overdoses, published in the CDC's Morbidity and Mortality Weekly Report, detailed a massive party where authorities appeared to anticipate drug use.
The Sports Arena rave — an all-night dance party featuring electronic music — attracted 45,000 attendees, according to the CDC; the promoter said 60,000 attended. Undercover narcotics officers and 14 ambulances were stationed on site, and emergency rooms were warned to expect patients.
The 24-year-old man died at home of multiple drug intoxication, the CDC said. Friends of the man told officials he had "used Ecstasy and cocaine at the rave and injected heroin at home afterward."
One emergency room patient suffered organ failure, requiring a stay in the intensive care unit after a seizure and liver and kidney failure. The man, who took Ecstasy but no other drugs, needed dialysis to detoxify his blood and was hospitalized for 28 days, the report said.
Dr. Caitlin Reed, a CDC physician who co-wrote the report, said Ecstasy can cause high blood pressure leading to stroke. The hallucinogen can also trigger seizures, releasing toxins that cause kidney failure.
"There are multiple mechanisms through which Ecstasy can cause death," Reed said.
The L.A. rave, "Together as One," is organized by Go Ventures and Insomniac, and has been held annually for more than a decade.