A general practitioner who treated a woman who died of an accidental oxycodone overdose in 2020 did not provide the "appropriate standard of care", a report has found.
A decision by the deputy Health and Disability Commissioner, released on Monday, found the doctor breached the Code of Health and Disability Services Consumers' Rights, after the GP agreed to increase the woman's daily dosage of the opioid.
Oxycodone is an opioid drug used to relieve moderate to severe pain. It can be formulated as either a long-acting or a short-acting medication.
The woman had been taking oxycodone since 2011, but increased her dosage of her own volition, because of increased chest pain linked to a recent lung cancer diagnosis.
But she asked her GP to formally prescribe an increase of 10mg three times a day to 20-30mg, which he agreed to.
Two days later the woman died at her home of "oxycodone toxicity".
The coroner subsequently referred the case to the Health and Disability Commission (HDC) in November 2021, following a complaint by the woman's daughter.
Deputy health and disability Commissioner Dr Vanessa Caldwell said the breach also applied to a lack of documentation related to the dosage increase.
"I would have expected documentation outlining the woman's prior average daily dosage to have been recorded," she said.
"This would have enabled the GP to review the risk of toxicity due to rapid up-titration (increase in dosage) and enabled a more accurate basis for calculating ongoing prescribing of the medication."
"Overall, I am concerned that the GP did not adequately account for the speed of increase and risks of accumulation."
During the investigation the doctor told HDC that he remembered the patient appearing well composed during the appointment, managing appropriately the grief of losing her husband, talking fondly of her children, and being optimistic about seeing a specialist for treatment of her recently diagnosed lung cancer.
The woman told the GP that she had increased her oxycodone dose due to the level of pain she was suffering and had experienced a "positive effect".
"This was not recorded in the clinical notes," the report said.
The woman, who had an extensive medical history, was on 10 other medications at the time.
"[The GP] told HDC that [the woman] had been prescribed zopiclone and oxycodone for years (initially prescribed by her previous doctor) and she had significant tolerance and understood the associated risks, and she had experience with these medications."
According to police statements, the woman's family saw her right up until her death and reported her "appearing well and like her normal self, other than complaining of a stitch, which was a regular occurrence".
The GP has informed the commission that in response to this case, he had made changes to his practice to improve the care provided to his patients.
"This included further education on opioid titration," the report said.
He had also offered the woman's family an apology for the code breach found in the investigation.
"I recommend that a written apology be sent to HDC within three weeks of the date of this report, for forwarding to [the woman's] family," the report said.