Nicola Jayne Lawrence died from a combination of methadone toxicity and the administration of multiple drugs at HMP New Hall in Wakefield in 2016.
Following an inquest into her death at Wakefield Coroner's Court this month, the jury concluded that there was a lack of training among staff and several chances to try and save the 38-year-old's life were 'missed'.
Ms Lawrence, who had Multiple Sclerosis (MS) and struggled with mental ill health and drug addiction, was recalled to prison to serve a 28-day sentence in September 2016.
In an initial health screening on September 9, she told staff about her MS, a wrist injury and dependence on drugs and was prescribed medications to manage her health needs. This included a prescription for methadone, which Ms Lawrence had never received before.
The inquest heard how there was no consideration given to the impact of methadone on the medication she was already prescribed for her MS. There was also a failure of communication with her MS specialist.
The hearing was told that at 9.30pm on September 23, prison officers noted Ms Lawrence, from Creswell in Derbyshire, was lying face down on the floor of her cell and snoring loudly.
They say she raised her arm in response to requests for her to get on to her bed but otherwise remained on the floor.
Staff checked on her at regular intervals. And at 11.30pm, they noticed she was no longer snoring and had become unresponsive, so called for emergency assistance.
The inquest jury returned a narrative conclusion, stating that the level of communication between health professionals and prison staff was lacking.
Jurors also said prison officers lacked training to recognise and deal with a prisoner on a methadone programme exhibiting signs and symptoms of drug toxicity.
They said had prison staff acted on concerns and contacted the health team between 9.30pm and 11pm, it is likely that Naloxone, a drug which could have reversed the effect of methadone toxicity and saved Ms Lawrence's life, would have been administered.
Ms Lawrence's mother Christine described her daughter as "very loving and caring".
She said: "The fact that the jury have confirmed she might still be with us if the level and nature of observations had been different is painful to hear.
"I hope that lessons have been learnt and the prison and healthcare providers put changes in place which mean that Nicola’s life has not been lost in vain. I do not want another family to have to go through what we have been through. "I would like to take this opportunity to thank the jury members that sat patiently for nearly three weeks listening to the evidence and for their full and thought out conclusion.”
INQUEST, a charity which provides independent advice to bereaved people following a death in state care or detention in England and Wales, has been working with Ms Lawrence's family since October 2016.
Executive director Deobrah Coles said: “Nicola’s death could have and should have been prevented by those who owed her a duty of care. The prison service must address the serious failings in this case as a matter of urgency."
Ms Lawrence was one of 22 women to die in prison in 2016.