Mr Pleydell had a series of ongoing medical conditions including Crohns disease, for which his family tried to persuade him to get treatment but he was "infuriatingly independent", the report said.
Coroner Ian Smith found that Mr Pleydell opted not to have medical supervision for his "very significant" inflammatory bowel disease.
He was reluctant to be referred to the gastroenterology department at Wellington Hospital and refused to have a colonoscopy done.
He was prescribed drugs, including codeine, for his condition but took them intermittently.
Coroner Smith found Mr Pleydell died as a result of accidental acute drug toxicity from a combination of codeine and the sleeping pill zopiclone, and possibly diazepam.
"It is clear that the deceased had a severe medical problem that he was reluctant to treat in the prescribed manner and preferred to deal with it in his own way."
There was no evidence to suggest his death had been a suicide, Coroner Smith said in his finding, released today.
- nzherald.co.nz