More than 22,000 New Zealanders aged 65 and over are taking a potentially dangerous combination of medicines that could seriously damage their kidneys.
The risks for those on heart failure or blood pressure medicines and water tablets who then take a non-steroidal anti-inflammatory (NSAID) painkiller is being highlighted during Patient Safety Week.
The Health Quality and Safety Commission and ACC call it a "triple whammy".
"Heart and blood pressure medication and pain relief medication affect blood flow in the kidneys, while diuretics can cause dehydration, which can also affect kidney function," says Dr Alan Davis, the commission's medication safety clinical leader.
The commission says between 2014 and 2016, the triple whammy was supplied on average 23,300 times per year to patients aged 65 and over.
Dr Davis says risk often arises when people who are taking heart failure or blood pressure medicines and diuretics then start on a NSAID painkiller.
Some are available on prescription, and others are available to buy from pharmacies and supermarkets.
Dr Davis says health professionals are advised not to supply the combination of the three medicines to people with risk factors for kidney failure - such as older adults, people with some kidney failure already, people at risk of dehydration and hypo-tensive patients.
The combination is involved in more than half of reported cases of treatment-related acute kidney failure, says Dr Davis.
"If you are taking this combination, it is important you visit your health professional to discuss and review your medicines. Do not stop taking your medication without consulting a health professional first," Dr Davis says.
New Zealand's Centre for Adverse Reaction Monitoring received 119 reports of kidney adverse reactions from January 2000 to December 2012 that were associated with the use of pain relief or anti-inflammatory medicines.
Between 2011 and 2016, ACC accepted more than 5800 treatment Injury claims related to medication errors and reactions.