Painkiller overdose spurs warning

Medical experts have warned that taking normal amounts of paracetamol for too long can cause liver injury.

The warning comes after Coroner Tim Scott ruled that a Wellington woman’s death was caused by an accidental overdose of paracetamol. Sarah Hunn, 52, was taken off life support on April 30 after suffering acute liver failure from taking too many of the overthe-counter painkillers.

Research published in The New Zealand Medical Journal in 2015 showed that, in one hospital, the common household painkiller accounted for nearly a quarter of all overdoses.

Wellington Hospital emergency medicine specialist Paul Quigley said paracetamol itself was not toxic, but an excessive amount of one of its ‘‘breakdown products’’ could cause serious liver damage.

‘‘We often get cases of liver injury from people taking a normal amount of paracetamol (1g), but too often and for too long – for example, when trying to treat dental pain,’’ he said.

‘‘There is a very successful antidote for paracetamol poisoning ... but only if administered within the first eight hours of poisoning. After that, it becomes steadily less effective.’’

National Poisons Centre medical toxicologist Michael Beasley said paracetamol was the biggest cause of acute liver transplants. It could kill in one-off high doses, or excessive chronic dosing.

In his findings, published yesterday, Scott said although Hunn was anxious and depressed before her overdose on paracetamol, it was not a suicide.

‘‘It is entirely possible that Sarah took excessive Panadol either by mistake or intentionally, but not with the purpose of taking her own life.’’

Neither her doctor nor psychiatrist thought she was ever actively suicidal.

Her husband, Tony Hunn, said yesterday that although his wife suffered occasional bouts of mental illness she was a productive and well-liked member of the community. ‘‘The message is you’d be surprised who you’d think is suffering from depression. It can happen to anyone, don’t be afraid to ask for help.’’

He told an earlier inquest that his wife had become severely depressed in the latter part of 2016.

Two days before she died, he saw her taking four paracetamol tablets over three hours, prompting him to hide the remaining tablets. Scott said it was highly likely she was taking too many pills out of her husband’s sight.

When she became unwell and was taken to hospital, a blood test showed high acid. More tests showed she had severe liver and kidney failure. High levels of paracetamol in the blood were the cause of her liver failure.

Scott found that, while Hunn intentionally took the paracetamol, it was ‘‘entirely possible’’ that it was an accident.

‘‘Many people – perhaps naively – believe there is a very high builtin safety margin in respect of dispensing drugs like Panadol and paracetamol.’’