The grieving mother of an artist who died after suffering a rare side effect to mental health medication said she believes her daughter’s death could have been prevented.

Hackney artist Sophie O’Neill, who was diagnosed with schizophrenia in 2003, died after suffering side effects from the anti-psychotic drug clozapine.

Opportunities were missed to pick up signs that she was suffering heart condition myocarditis and liver failure, a jury inquest concluded.

Ms O'Neill trained at Central St Martin’s School of Art and was a leading light at Hackney-based charity Core Arts.

She was being treated at the City and Hackney Mental Health Unit run by the East London NHS Foundation Trust in December 2019 after suffering a relapse, and it was thought she had missed two days' doses.

She collapsed within an hour of taking her last dose on December 20 and went into cardiac arrest.

Despite attempts to resuscitate her at the nearby Homerton Hospital, the 37-year-old artist died the next day.

Consultant psychiatrist Fatema Ibrahim said Ms O’Neill was withdrawn and very unwell when she was admitted. The plan was to restart her on a lower dose of clozapine and gradually increase it. Observations were taken four times daily, including before and after doses.

Dr Ibrahim said clozapine is used when other medications have failed.

It is provided only by hospitals and the inquest heard patients’ blood must be monitored for the first 18 weeks of taking it. Myocarditis is rate but most likely in the first two months, and can also happen after the drug is restarted.

The inquest heard the East London NHS Foundation Trust’s clozapine policy states that high heart rates could be a risk marker and should be investigated and the drug stopped if myocarditis is suspected.

Ms O’Neill’s heart rate was over 100 bpm in many observations, and over 120 bpm six times. Clozapine was stopped only by an on-call doctor once, on the night of December 18, and later restarted.

Her highest heart rate reading was 141 bpm on December 20, just before her final dose.

Blood tests showed raised levels of CRP, a protein made by the liver in response to inflammation, from December 17 but did not prompt suspicion of myocarditis.

Junior doctors believed Sophie was suffering a respiratory tract infection, the inquest was told.

Dr Ibrahim said she had not been made aware of Sophie’s abnormal observations or raised CRP levels and was not made aware when on-call doctors were involved. If she had she would have asked for further investigation, she said.

The jury at Bow coroners’ court found inadequate communication to the consultant, and a lack of action after observations in the two days before she died “contributed to the loss of a chance” to prevent her death.

Ms O’Neill’s mother Dorothea, who visited regularly, raised concerns that her daughter seemed “incredibly sleepy” the day before she died.

She said her daughter had swollen ankles but this was put down to a lack of movement.  A cardiologist told the inquest that fatigue and swollen ankles can be symptoms of heart failure.

Her mother said she had to escalate concerns about her daughter’s deteriorating physical health.

Assistant Coroner Sarah Bourke said she had concerns about the recording of observations and escalating abnormal observations. The coroner said changes need to be made to East London NHS Foundation Trust’s policies.

Her mother Dorothea had to push for an investigation and inquest. Speaking afterwards, Mrs O’Neill said: “If repeated and avoidable errors had not been made by the trust, Sophie’s death might have been prevented.

“Had Sophie’s care been adequate, we believe she might still be here today. We hope that the trust soon takes and evidences the actions they have promised in order to prevent future deaths.”

In a statement East London NHS Foundation Trust said: “Our trust expresses its deepest sympathies to the family and friends of Sophie O’Neill. We acknowledge the findings from the inquest and remain committed to actioning issues of concern outlined.

“As a trust, we recognise the benefits and risks of clozapine and will continue to ensure that our staff are fully aware of these.”