District Health Boards spent more than $280 million over the past three years treating patients who became sick after being prescribed the wrong medication.
Though the Ministry of Health says some of those admissions were unavoidable, as it could have been an unknown allergic reaction to a drug, experts have raised "serious concern" about hundreds of preventable cases, such as a patient who died after being given two drugs that shouldn't be used together.
New Zealand Nurses Organisation (NZNO) organiser Donna MacRae told the Herald it was an issue that was putting patients in unnecessary danger and was also "money down the drain".
Cases investigated by the Health and Disability Commission include:
• A 75-year-old woman died after a Lakes District Health Board doctor gave her two drugs that should not be used together.
• A 7-year-old with cerebral palsy was prescribed baclofen, a muscle relaxant, but the pharmacy inadvertently gave them 10 times the intended amount. The child had three hospital visits that involved increased seizures, shortness of breath and deep breathing.
• A woman was mistakenly prescribed Salazopyrin instead of Pentasa, which resulted in her being hospitalised with a diagnosed deranged liver function.
Figures released exclusively to the Herald reveal that DHBs spent $280,102,298 treating patients who turned up to hospital with adverse drug reactions between 2015 to 2018.
This cost is likely to be just the "tip of the iceberg", as over-prescribing or mixing the wrong medication can lead to all sorts of health issues that aren't always recorded by DHBs as ADRs, MacRae said.
According to the DHBs' ADR admission data - given to the Herald by the New Zealand Taxpayer Union - Canterbury DHB spent the most during this time period, reaching just under $60 million. Waikato DHB was next, spending just under $40m, followed by Waitemata DHB with just over $30m.
Medication errors prompts call for nationwide digital system
Counties Manukau DHB spent the lowest, which was less than $200,000.
An NZTU data analyst said this was "extremely low", which indicated either the DHB was significantly more efficient than every other DHB or its reporting methods for ADR admissions were not accurate and needed revisiting.
DHBs warned these disparities were not an accurate comparison, as they all collected the data differently.
Canterbury DHB chief medical officer Dr Sue Nightingale said obviously they did not wish to see any admissions as a result of ADRs but it was not possible to single out one main cause from the data collected.
"[ADRs] range from single medication errors such as someone taking more allergy medicine than the packaging advises, all the way to the highest harm possible.
"Some of these would obviously be preventable in home and in the community, as well as in the hospital setting," Nightingale said.
The Herald sought further response from Counties Manukau, Waitemata and Auckland DHBs.
Health Minister David Clark refused to answer whether he thought this was a concern and if he saw it as preventable, saying: "Adverse drug reactions are a clinical matter. As such it is more appropriate for the Ministry of Health to respond."
Ministry of Health pharmacy chief advisor Andi Shirtcliffe said this wasn't an accurate representation as some of the data included cases where an adverse drug reaction was not the primary cause of hospital admission.
"It can be challenging to identify whether the primary cause of an individual being hospitalised is an adverse drug reaction.
"Reported figures are also complicated by health professionals being encouraged to report adverse drug reactions on suspicion rather than confirmation," Shirtcliffe said.
DHBs define ADR admissions as: "Unwanted or harmful reactions experienced following the admission of a drug or combination of drugs under normal conditions of use and is suspected to be related to the drug."
Under that category are "preventable ADR admissions", which are caused by medication error - either incorrect medication, dosage, timing or administration of drugs to a patient with a known allergy.
Medication error complaints:
Between 2009 and 2016, 310 complaints about medication errors were investigated by the Health and Disability Commissioner.
"I was struck by the number of errors in which a failure to follow policies and procedures was a contributing factor," Health and Disability Commissioner Anthony Hill said in a medication errors report released December last year.
"Deliberate deviations from policies and procedures can seriously compromise patient safety and result in consumers not receiving an appropriate standard of care," Hill said.
He called for a nationwide roll-out of electronic systems including an appropriate electronic prescribing system and electronic health record.
He also recommended that "organisational leaders foster cultures that support staff to do what is required of them".
Also to ensure individuals were doing the basics well like "reading the notes, talking to the patient, asking the questions, and undertaking the necessary checking procedures".
Since then, much of the focus has been on getting GPs enrolled with The NZ ePrescription Service (NZePS), which provides a secure messaging channel for prescribing and dispensing systems to exchange prescription information electronically.
The Ministry of Health said that as of March 2019, NZePS was used by 160 general practices, which was up from 87 in March 2018.
In March 2019, prescribers generated 251,542 ePrescriptions compared to 148,450 in March 2018.
Pharmaceutical Society of New Zealand manager of practice and policy Chris Jay said a lot of work was underway to address this issue but there was still room for improvement.
Jay said there was room for the pharmacy workforce to be utilised better - for example, including them within general practices, hospitals and other areas of health.
"It means pharmacists could help sit down with patients to prevent any medication related problems as well as optimising their medication."
Some DHBs were already starting to do this, Jay said, and he encouraged others to get on board.