A woman who was admitted to hospital with a stomach complaint died after being given medication intended for another patient.

Barbara Maguire, 51, was given medicine prescribed to a patient who had previously occupied the bed she was allocated. Ms Maguire, who had been admitted to the emergency ward of the Stobhill Hospital in Glasgow at the end of 2004 after complaining of stomach pain, died within 24 hours of being given the drugs.

NHS Greater Glasgow admitted the mistake yesterday but refused to say what medication had been administered or how the error occurred. More than a year later, her family say they are still waiting for an explanation. Thomas Bryan, who had been Ms Maguire's partner for more than 25 years, said he was dismayed at the fatal mix-up and complained at the manner in which the death was handled by the authorities.

Mr Bryan said: "I can't understand why anyone would give her drugs that were supposed to be for someone else. After she died, the police came to see me and took a statement. Then I got a letter from the procurator fiscal, saying they were investigating. I'm still waiting for answers."

A spokesperson for NHS Greater Glasgow said: "We met with Ms Maguire's family at the time of her death, confirmed that the wrong medication had been given and expressed our sincere regret.Over the past year we have provided information as requested to the procurator fiscal's office including in the past week a final report on the actions we have taken to prevent this happening again."

The fatal error was revealed a week after the same health authority admitted that a leading cancer centre had administered potentially lethal doses of radiation to a teenage girl with a brain tumour.

Lisa Norris, 15, from Ayrshire, was given potentially deadly doses 17 times at the Beatson Oncology Centre where she was treated for a brain tumour. An initial investigation has found that the overdoses were caused by human error. The long-term effects of the overdoses are not known.

The disclosure about Ms Maguire's death will add to concern over a study, published last week, which revealed that thousands of elderly people in care homes were being given the wrong medicine, someone else's medicine or doses that were dangerous. The Commission for Social Care Inspection found that nearly half of all care homes in England failed to meet minimum standards for managing medicines.

The study found that staff were poorly trained and that records were badly kept. More than 5,000 of 11,500 homes for people over 65 failed to meet minimum standards.