A coroner has raised concerns over prescribing errors at a London prison following the death of an inmate.
In a prevention of future deaths report published last month, assistant coroner for Inner London South Jenny Goldring said that despite “evidence of significant improvements in the healthcare provision” at HMP Thameside, reports dated as recently as last year identified “significant risks with the management of medicines” alongside “prescribing errors”.
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The report comes after an investigation into the death of Mark Smith, an inmate at HMP Thameside, following an “epileptic seizure leading to cardiac arrest” in 2019.
While the seizure and cardiac arrest was recorded as the direct cause of death, Goldring noted that “toxicity related to pregabalin”, alongside a “low sodium valproate level” and “an overall decline of clinical state and metabolic condition”, were “significant” contributing factors.
“Conflict”
According to the report, Smith had “a documented history of asthma, epilepsy and depression” and was already prescribed medicines “including pregabalin, dosulepin and sodium valproate” before his arrival at HMP Thameside on January 8, 2019.
“All medication was maintained by the prison GP as before, with the exception of co-dydramol, which was replaced by an as-and-when required dose of diazepam, and a change of route for pregabalin administration from tablet to liquid, on a dose of 50mg per day for the first seven days of prison admission, increasing to 100mg per day thereafter,” it said.
Goldring highlighted that there was “a conflict between the pregabalin prescription shown on Systm 1 prison medical records” and the “dose recorded on the administration records”, with Smith receiving a higher dose of the drug at HMP Thameside.
“There was a failure to correct the prescription on Systm 1, despite it appearing on a minimum of six occasions,” she said.
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Goldring added that Smith was admitted to the prison inpatient unit after a “decline in his mental health”, and also “experienced seizures and hallucinations” during his first week at the prison.
She said Smith was admitted to Queen Elizabeth Hospital in Woolwich on January 17 after being found “on the floor of his cell, unresponsive and foaming at the mouth” - and upon arrival at the hospital, continued to be administered according to the Systm 1 dosing plan, “including the increase in pregabalin dose to 100mg”.
And she noted that a member of prison healthcare staff “raised concerns” about Smith’s condition and “requested a multidisciplinary team meeting” with the hospital ahead of his discharge back to HMP Thameside, but added that “this did not take place”.
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Following his discharge back to the prison, concerns were raised that Smith “had lost power in his limbs” and “had significant mobility issues, risk of falling and high levels of confusion”.
The report said Smith was placed into a disabled cell which “allowed more room and reduced risk of serious injury”, but which meant that “constant observations through a closed door were not possible” - and Smith was instead observed intermittently “every 15 minutes”.
It added that when Smith was readmitted to hospital on January 30 - after “having seizures on and off” for several hours - “multiple members of prison healthcare staff” met with hospital doctors “who had insufficient briefing on [his] history, including a lack of NHS patient number”.
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During his admission, Smith received “2.5ml of liquid pregabalin twice daily”, before being discharged back to HMP Thameside on February 4.
That night, Smith was “observed sitting on the floor acting in an erratic manner”, but prison healthcare staff’s request for a cell unlock were “declined due to it being a non-emergency”.
And the report noted that the following day, after Smith was attended to following being found in a hypothermic state, “11 further observations by healthcare staff were missed”.
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It said that alongside “an inadequate handover” between day and night healthcare staff regarding Smith’s condition, there were seven “falsified entries” made on nursing observation charts that evening, and the unit was “inadequately staffed”.
On the night of February 5, after a nurse was “unable to observe” Smith’s breathing, a prison custody officer (PCO) entered Smith’s cell with a defibrillator - but “found it to be inadequately equipped, without batteries or pads”.
After failed attempts at resuscitation by both PCOs and paramedics, Smith was pronounced dead at 00:38.
Missed opportunity
Goldring said the “nature and extent of medical care and clinical observation by prison healthcare staff” between February 5 and 6 “possibly made a material contribution” to Smith’s death.
She added that the “inadequacy of handover and basic observation” and “failings in sufficient record-keeping” meant that “signs and symptoms of an epileptic seizure were not observed” - and an “opportunity to perform life-saving measures in either administering medication to stop the seizure” or “timely CPR” was therefore missed.
And she said Smith was “administered doses of liquid pregabalin of more than 2.5ml by healthcare staff while at HMP Thameside”, which “probably made a material contribution” to his death.
“Life-threatening consequences”
Goldring raised a number of concerns in the report, including that “the wrong dose of medication could be prescribed or administered with life-threatening consequences”.
She said that while she had “seen evidence of significant improvements in the healthcare provision at HMP Thameside” since the year Smith died, there were reports noting “significant risks with management of medicines” and “prescribing errors” as recently as 2024 to 2025.
“Whilst recent internal audits in 2025 show significant improvements, medication incidents are recorded in late 2025, and the principal pharmacist notes a very busy site with multiple prescriptions screened daily,” she added.
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She also noted that “during the inquest it proved difficult to establish how Systm 1 operated and whether there were risks inherent in the system itself”.
“For example, it was suggested the system would convert mg into ml or pre-populate entries such as 100ml,” she said.
The report was sent to Lewisham and Greenwich NHS Trust, the director at HMP Thameside, the director general of HM Prison and Probation Service and the CEO of health provider Practice Plus Group.
Goldring said “action should be taken to prevent future deaths” and the parties addressed “have the power to take such action”.