An 87-year-old woman died after her carers gave her the wrong medication, a coroner was told.
Heather Planner, from Butler’s Cross in Buckinghamshire, died at Wycombe Hospital on 1 April from a stroke.
Senior coroner Crispin Butler heard three staff from Carewatch Mid Bucks had failed to spot tablets handed over by the pharmacy were for a male patient.
Mr Butler said action should be taken to prevent similar deaths.
A hearing in Beaconsfield on Thursday, where he issued a Prevention of Future Deaths report, followed an inquest in November.
In the report he said he was told at the inquest that the carers from Carewatch Mid Bucks gave widow Mrs Planner the wrong medication four times a day for two and a half days.
The hearing in November heard the mother of one suffered a fatal stroke because she did not receive her proper apixaban anticoagulation medication.
Mr Butler said he would send his concerns to the chief coroner and the Care Quality Commission.
He said there was no procedure in place to ensure individual carers read and specifically acknowledged any medication changes.
The coroner added: “There is a specific concern in Mrs Planner’s case about the robustness of the subsequent Carewatch investigation and any learning that would arise to prevent incidents in the future.”
Jonathan Planner, 56, her son, previously said he would be taking legal action against Carewatch and the Westongrove pharmacy in the hope of preventing the death of another patient.
He said: “In my view the carer had a duty to check they were in receipt of the right medication and they did not check. It was a huge error.”
Carewatch, which provides home care services in Aylesbury, High Wycombe and Wendover, has been asked for a comment.