A Gold Coast man has been sentenced to 18 months in jail for bashing a paramedic who was treating him in the back of an ambulance.

Matthew Thielemans-Stirling, 25, had fallen unconscious after taking prescription medication which belonged to his mother, who had taken her own life days earlier.

His sister had also killed herself two months earlier.

Queensland Ambulance Service paramedic Brad Johnson was assaulted. ( Supplied: Queensland Ambulance Service )

While being treated in the back of an ambulance in Upper Coomera, Thielemans-Stirling awoke, and lashed out at paramedic Brad Johnson, 48.

Over a three-minute outburst, Thielemans-Stirling hit Mr Johnson a number of times in the head and the eye, his sentencing hearing in the Southport Magistrates Court heard.

"I'm going to kill you," Thielemans-Stirling said during the assault, the court was told.

Ambulance officers gathered outside court to support Mr Johnson, holding signs with slogans such as "#ZeroTolerance".

Matthew Thielemans-Stirling took a quantity of prescription medication before falling unconscious, his lawyer says. ( Facebook )

Thielemans-Stirling pleaded guilty on Wednesday morning to serious assault of a public officer.

He also pleaded guilty to common assault, for threatening to hurt the female ambulance driver.

The court heard he had a history of violence and had previously spat at a police officer.

"He had a blatant disregard for public officers and there is a need for deterrence for these sorts of assault," prosecutor Nina Sulzer said.

Magistrate Dermott Keogh sentenced Thielemans-Stirling to 18 months in prison but he would be eligible for parole in October.

The maximum jail time for assaulting health workers is 14 years after the penalty was doubled in 2014.

Despite the increased penalty, assaults were still increasing and last financial year more than 3,300 healthcare workers were physically assaulted, State Government figures showed.

To combat the rise, a $1.3 million advertising campaign was launched on television, billboards and bus stops.

Paramedic 'disappointed' by sentence for Thielemans-Stirlings

Speaking outside the Southport court, paramedic Kyla Golds expressed her disappointment at the leniency of the sentence handed down.

"We want mandatory minimum — the maximum is 14 years for a serious assault — so why is that not happening, why are we not getting that?" she said.

"I'm disappointed that he has got as little time as he has.

"Who knows in six months when he is released is he going to do this again to one of us? It's a scary thought."