For years Margaret McCausland suffered migraines. She was prescribed a cocktail of sedatives and painkillers to relieve her pain - drugs that were supposed to help her, but may have cost her her life.
The 50-year-old died on April 1 when her car ran off State Highway 2 just south of
Bell Rd, Papamoa, and smashed into a tree. She was travelling at up to 160 km/h.
A Tauranga Coroner's inquest was told on Friday that Mrs McCausland visited four doctors in the months leading up to her death.
Alarmed motorists had called police after they were overtaken by the 50-year-old's Mazda saloon. One described her driving as like "that of a drunk driver".
An autopsy revealed Mrs McCausland had taken sedatives and painkillers, including Zopiclone - a drug used for insomnia. Pathologist Dr Richard Massey found Zopiclone levels "double the threshold of toxicity".
He said it was likely the drugs would have impaired Mrs McCausland's ability to judge speed and distances. The effects might also have caused her difficulty in controlling her car.
Constable Rob Rowley told the inquest Mrs McCausland suffered severe migraines most of her life. On the day she died she had been treated by a doctor at Bethlehem, Tauranga.
Shortly before the crash she had gone clothes shopping. A shopkeeper had been concerned about her behaviour and told police she appeared "quite out of it".
Mrs McCausland's car failed to round a slight bend and careered off the road. She died at the scene.
Police investigations revealed Mrs McCausland, who lived at Te Puke, was seeing two doctors - but neither knew she was receiving treatment at the other practice.
The Housing New Zealand worker regularly travelled to the East Cape.
Mr Rowley said that because of the remoteness she would carry supplies of painkillers that would need a registered nurse to administer by injection.
He said Mrs McCausland had become drug-dependent, which had ultimately led to her death.
Coroner Michael Cooney ruled death was the result of multiple injuries sustained in the crash.
- NZPA