A man died as a result of "excessive drug use" after falling asleep in the same position "for maybe 20 hours", an inquest heard.

Karl Miller, 30, of Allonby was found by his mother in his grandmother's house at Aspatria on November 28 and died from his injuries in the Cumberland Infirmary on December 1 last year.

Assistant coroner Dr Nicholas Shaw concluded it was a drug related death, saying "most likely an excessive dose of diazepam".

He said Mr Miller had "fallen asleep and just stayed asleep", probably in the "same position for maybe 20 hours".

"The pressure on his legs and feet and arms from where he has slumped forward is going to cause rhabdomyolysis (the breakdown of muscle)."

Dr Shaw said this "lead to kidney failure and ultimately death".

"If an ambulance had not been called I suspect he would have died within the next hour or two in that room," he added.

A post mortem found the cause of death was multiple organ failure due to rhabdomyolysis, probably caused by "prolonged lying in one position".

Mr Miller's mother Heather Miller found her son at about 3.30pm on November 28.

She said she had visited earlier that day, before her mother, who has dementia, went to day care, but heard "snoring" and thought he was asleep.

It was when she returned later that she made the discovery.

Mrs Miller phoned an ambulance before "frantically trying to find out what had happened".

She said she found a phone on the floor and an unknown number, which she called later that day and spoke to a male called Simon, from Workington.

"He told me he had given Karl one of something," she said. "He told me it was a morphine-based drug."

Dr Julia Capper, a consultant at Carlisle's Cumberland Infirmary, said Mr Miller was taken into A&E by paramedics at 5.09pm on November 28 and was later transferred to intensive care.

On December 1, Dr Jon Sturman had discussions with Mr Miller's family before life support was withdrawn.

Mr Miller's GP at Aspatria Medical Centre, Dr Julie Saxton, said he had a history of agoraphobia and panic attacks and had been encouraged to engage with the community mental health team.

She said he had a twice weekly prescription of diazepam, which is used to treat anxiety.

His mother said his anxiety had developed as he got older and "he struggled to go outside" at times.

She said he "self prescribed for anxiety" by getting "extra Valium (diazepam) off the street".

Mrs Miller also told the inquest her son, who had worked on a chicken farm, grew up in Aspatria and attended Richmond Hill Primary School and Beacon Hill Community School.