A coroner has made AHPRA notifications about two health practitioners after a young woman unexpectedly died the day after her methadone dose was bumped up
The Victorian woman, who was 33 years old at the time of her death, suffered chronic back pain due to workplace issues and had a long history of treatment with opioids.
From around 2007 her chronic pain was primarily managed by a doctor from a Melbourne sports medicine clinic, as well as a pain specialist. At this time she had been prescribed oxycodone and diazepam.
In 2017 the patient was admitted to a Victorian rehabilitation centre and, under the care of the pain specialist, began ketamine infusions in an effort to wean her off high-dose opioid analgesics.
She was then transitioned from oxycodone onto methadone.
Following discharge her prescription was for 10mg tablets of methadone, with instructions to take a regular half tablet dose (5 mg) twice per day and up to 5 mg three times per day in addition – for a total of 25mg daily.
When the patient returned home following the ketamine infusion and opioid rotation, her mother noticed her daughter’s medications made her “drowsy and disoriented”, that she slurred her speech and would often fall asleep at various times including whilst sitting at the dinner table.
Her mother was concerned at the level of drugs her daughter was taking, and had the impression that she was made so drowsy by her medication that she was not fully aware of when she had taken her pills and how many pills she was taking.
However a few days later the patient had a phone conversation with the pain specialist about “bumping up the medication … [as] she felt the pain was still intrusive”, and she also had a phone conversation with the sports physician.
On 26 May, the two doctors confirmed with each other – via text message – that the woman’s methadone dosage was to be increased from 5 mg to 10 mg, three times daily (effectively an increase from 25mg daily to 30mg daily).
On that same day, she attended her local pharmacy and was dispensed one box of 20 tablets of 10mg methadone from the script, with the instructions ‘Take ONE tablet THREE times a day’. The script had no repeats.
That night she fell asleep on the couch. The next morning she was found by her mother still on the couch with her lips unusually blue.
Emergency services were called and she was transferred to the Intensive Care Unit (ICU) with a provisional diagnosis of opioid-related respiratory depression resulting in cardiac arrest.
However after a few days in the ICU, it became clear she had sustained a severe hypoxic brain injury and the decision was made to withdraw life support measures.
The young woman died on 4 June 2017.
Victorian Coroner Simon McGregor, in his findings without inquest, accepted the cause of death was hypoxic ischaemic encephalopathy complicating mixed drug toxicity, with no evidence of intention to self-harm.
Mr McGregor found she had “died as the unintended consequence of the consumption of her prescribed medications”.
One possibility was that her death was directly caused by taking her prescribed doses of medications. Another possibility put forward by the woman’s mother was that she took more than her prescribed doses due to confusion caused by the medications taken at the prescribed doses.
“Although I cannot find that either scenario is more likely than the other, I am satisfied that [her] death was caused directly or indirectly by the prescription of medications, in particular methadone, in circumstances where her methadone dose had been increased on the day before her fatal overdose and she had been provided with a script for 20 tablets of 10mg methadone,” he said.
Meanwhile the coroner highlighted concerns that no in-person review occurred on 26 May 2017 before her methadone dosage was increased.
“It is likely that, had [she] been reviewed on that day, her dangerous levels of sedation would have been clear.
“What is certain is that this was a missed opportunity to detect whether [her] methadone dose was causing dangerous side effects and whether increasing it would put her in danger of overdose,” he said.
“I consider that the failure to require an in-person review before increasing her dosage impaired the ability of both practitioners to properly assess the dangers of this increase.”
In addition, the conversation between the two doctors about increasing her dose occurred via a “brief and ambiguous text message conversation”.
“If [their] conversation with [the patient] employed a similar ambiguous shorthand, there was ample opportunity for her to become confused and take a higher dose of methadone than was intended to be prescribed. Such confusion might have led to her death. Unfortunately, the lack of documentation of [their] discussions with [the patient] makes it impossible to conclusively determine what she was told about her new prescribed dosage,” said the coroner.
He concluded that both practitioners had “practised in a manner that placed the public at risk of harm [and] the care they exercised was below the standard reasonably expected.”
The coroner made notifications about the two practitioners to AHPRA.
Separate coroner’s findings last year, also in Victoria, revealed a 32-year-old Melbourne woman died in February 2018 from mixed drug toxicity within two days of commencing methadone maintenance therapy.
Forensic pathology registrar Dr Melanie Archer, from the Victorian Institute of Forensic Medicine, told the coroner’s court that the greatest risk for methadone toxicity is in people who have just started the methadone maintenance program, with the highest risk of death within the first week.