AN INVESTIGATION is under way after drugs were incorrectly administered to a elderly hospital patient, who later died.
The blunder, which occurred at Croydon University Hospital in November, has been classed as a 'never event' - an incident so serious it should never happen.
Health experts are exploring whether the mistake had any role in her death eight days later.
A separate investigation has been considering the same question following the death of another elderly woman who passed away after being given a drug she had a "documented" allergy to last June A report into her death has yet to be completed.
The latest incident is mentioned briefly in documents to be discussed at a Coydon Clinical Commissioning Group (CCG) board meeting held on Tuesday.
It said the mistake, originally defined as a "serious incident", had been escalated to a never event.
Croydon Health Services (CHS), the trust which runs the hospital, said it had apologised to the patient and her family.
Steve Ebbs, medical director, said: "The never event raised in November relates to a patient whose drugs were incorrectly administered.
"We gave our heartfelt apology to the patient and his family at the time and we are now investigating how this happened.
"This patient was an elderly woman with underling health conditions but, as this investigation is ongoing, we cannot release any further details."
CHS says the hospital has performed better than the national average for "harm-free care" since April 2014.
There have, however, been several patient deaths in the aftermath of clinical errors.
In June, an elderly woman was given four doses of Tazocin, an antibiotic used to treat bacterial infections, even though her medical records showed she was allergic to the drug.
The patient subsequently developed a fatal skin condition and died. An investigation was expected to have finished shortly after the incident was first reported by the Advertiser in August, but this week CHS said the report was awaiting final approval by the CCG.
In October, a senior staff member at the hospital leaked details of a series of serious incidents involving patients being given the wrong type of food.
In the most serious example a patient in his early 70s, on liquid diet, died after being fed solid food by staff.
In another case a man who was 'nil by mouth' went into respiratory arrest after being given soup, though he later recovered.
The errors were caused by forms being filled in incorrectly and, in once case, a sign containing dietary information fell behind a patient's bed.
A safety alert sent to staff, and leaked to the Advertiser, said a "trend" of patients being fed incorrect diets had resulted in "severe and catastrophic consequences".
CHS said it has completed investigations into each incident and improved the way it feeds patients on restricted diets.
Following the latest 'never event' Mr Ebbs said: "We will always thoroughly investigate any serious incidents where our patients have not have received the high standards of care that we expect.
"This includes never events, which should not occur if the right safeguards are in place.
"It is important, not just for the trust but across the NHS, that we learn from these to put the right measures in place."
The November investigation followed ten serious incidents at the hospital in October, including three falls, one collapse after surgery, one surgical error, one unexpected death and the death of a child. The trust said investigations were underway.
THE 'never event' is the latest in a number of troubling incidents at Croydon University Hospital:
JUNE 2014: Elderly woman dies after being given antibiotic she has as documented allergy to.
JULY 2014: A man in his 60s is fed soup despite being on a 'nil by mouth' diet. He passed away two months later.
SEPTEMBER 2014: Patient chokes after being fed solid food when doctors had prescribed a puree diet. He died around a week later. Another patient on a puree diet is accidentally fed a sandwich but recovers.
OCTOBER 2014: Family, friends and supporters of terminally ill Marcus Campbell stage protest outside hospital after being told he will not be resuscitated if he goes into cardiac arrest.
NOVEMBER 2014: Employment tribunal rules hospital sacked a senior doctor for raising safety concerns following the death of a patient.
JANUARY 2015: Hospital becomes first in London to declare an "internal major incident" due to huge demand for services.