Philippa Gillespie died after hospital penicillin error
A Pembrokeshire cancer patient died from an allergic reaction to penicillin administered in error by hospital staff, an inquest has heard.
Philippa Gillespie, 59, was admitted to Withybush Hospital, Haverfordwest, on 8 January 2014 with symptoms relating to her terminal lung cancer.
She was prescribed Augmentin, despite her penicillin allergy listed on her notes, and died three days later.
Hywel Dda University Health Board has apologised for its "failings".
Coroner Mark Layton recorded a narrative verdict at the inquest at Milford Haven.
He said: "Philippa Gillespie died from an allergic reaction to penicillin administered in error by hospital staff."
Mrs Gillespie's partner Roy Conolly, from Haverfordwest, told BBC Wales: "She knew 2014 would be her last year, but we didn't expect her to go quite like that - we didn't have time to say goodbye."
She experienced a cardiac arrest and died on 11 January.
In a letter to Mr Conolly, Hywel Dda University Health Board's deputy chief executive Joe Teape admitted to failings.
The letter, seen by BBC Wales, said: "The standard of record keeping both at initial assessment and following Mrs Gillespie's anaphylaxis reaction is below the standard the health board would expect.
"The health board admits that a qualifying liability does exist on the basis that there was a failure to adhere to health board policies and procedures by the medical and nursing staff."
It added: "I hope you will be assured that a complete and thorough investigation has occurred and that we have taken immediate actions to prevent a similar incident occurring in the future."
In a separate statement, Caroline Oakley, the health board's director of nursing, quality and patient experience, said it had been in touch with Mrs Gillespie's family to "unreservedly apologise for the failings".
She said immediate action was taken as a result and safety alerts were issued to all staff.
She added: "We have repeated training for all staff in relation to medication administration and introduced an all Wales monthly medication safety audit to ensure that any practice which has the potential to lead to harm is improved."