A man has died after paramedics, attempting to treat him for a suspected drug overdose, were attacked by dozens of angry men in Sydney’s west, the union says.

Paramedics were called to a Riverwood unit block at about 8am on Sunday for a 25-year-old man suffering a suspected drug overdose, the Australian Paramedics Association said.

Family members of the dying man became irate and tried to intervene, the APA says.

Up to 80 angry males quickly gathered at the unit and allegedly threatened the health workers and charged at a female paramedic, injuring her shoulder.

“Paramedics were forced to fend off angry males who eventually forced them to stop treating the patient who was in cardiac arrest and subsequently died,” APA secretary Steve Pearce said.

The paramedics barricaded themselves inside the unit as the violent mob demanded a defibrillator and drugs believing they could treat the young man, Mr Pearce added.

Play Video There's calls for firefighters, paramedics and police to be forced off the front line after serving for a set period of time. The West Australian Video There's calls for firefighters, paramedics and police to be forced off the front line after serving for a set period of time.

About 150 police arrived at the scene, including the Public Order Riot Squad, to rescue the paramedics.

But the patient had died.

“On this occasion the stupidity of these people have taken the life of their family member,” Mr Pearce said.

“We don’t want any more people to face the horrifying situation of their loved ones dying because paramedics are unable to treat patients after threats of violence.”

He called for faster intervention by police and said attacks on paramedics in the Bankstown area had become a regular occurrence.