A verdict of medical misadventure has been returned after an inquest heard recommended liver function tests were not carried out on a woman to monitor the effects of a drug that ultimately led to her death.
Dymphna Dykes presented to Tallaght University Hospital on February 24th, 2021, with acute liver dysfunction, having taken Isoniazid for a six-month period to treat latent tuberculosis.
Her condition deteriorated and she was transferred to St Vincent’s University Hospital on March 15th to be considered for a liver transplant but was deemed unsuitable.
Despite cessation of the drug two weeks before her admission, she died on March 26th from multi-organ failure as a result of acute liver failure.
RM Block
The inquest heard this acute liver failure was a result of Isoniazid toxicity. Pathologist Dr Niamh Nolan described this as “very rare”, affecting one per cent of patients.
Dr Nolan, who carried out the postmortem examination, said Ms Dykes’ liver was “markedly shrunken” due to loss of the normal liver tissue. She said the organ weighed ”390 grams and you would normally expect a liver to weigh 1,500 grams”.
Persons taking Isoniazid require monthly liver function tests to monitor its effects. The inquest heard these tests were not carried out during the six-month period.
Professor Seamas Donnelly, who prescribed the medication, apologised to the Dykes family, saying: “Myself, the GP and the system let the family down.”
“As the prescribing physician, the buck stops with me,” he said.
On prescribing the medication in August 2020, Prof Donnelly sent a letter to Ms Dykes’ GP, Siobhan Kierans, advising her of the development and asking her to carry out monthly liver function tests to monitor the drug’s effects.
In the letter, he said he would arrange them at Tallaght University Hospital should this not be possible.
In subsequent follow-up consultations, meanwhile, he assumed the monthly tests were being conducted, despite not receiving any responding correspondence from the GP, which he said was not atypical.
He recalled asking Ms Dykes if the tests were being done and she said yes, though he acknowledged in hindsight these were other routine blood tests not concerning the liver.
Since her death, he said he has begun asking GPs to confirm receipt of such correspondence by email, “but I’m not getting responses”.
Ms Dykes’ GP, Ms Kierans, who said she is no longer practising, told the inquest she read the correspondence but did not recall “reading all of the letter”, saying it must have “went under the radar”.
“I don’t recall reading about the liver function tests,” she said. She did not recall Ms Dykes saying she required them.
Ms Kierans said she had never initiated the drug before and had never been asked by a consultant to monitor “unusual drugs”.
“I obviously didn’t have enough personal knowledge on the drug itself,” she said, adding at one stage that she was perhaps “naive”.
She said her practice received about 40 letters per day, adding: “Obviously, this one wasn’t highlighted enough and brought to my attention.”
“I assumed she was seeing him (Prof Donnelly) on a regular basis,” she said.
Put to her by counsel for the family, William Reidy, that it appeared there was a “lack of system” in her practice, she said it had “never happened before”.
Noting that the recommended monthly tests were not conducted, coroner Dr Cróna Gallagher returned a verdict of medical misadventure.
She said it was a neutral verdict that reflected the unintended consequences of the treatment and events thereafter.
Speaking on behalf of the family, solicitor Aidan Flahavan said while the coroner made no recommendations, they “hope that lessons are learned from it”.
