The head of the drug buying agency Pharmac says people who use sleeping pills should not be alarmed by a study linking their use in high doses to the risk of an early death.
Medsafe is to investigate the findings of the study by US researchers which has been published in the British Medical Journal.
Pharmac says almost 546,000 prescriptions for the common drug Zopiclone were issued in New Zealand in the year to June 2011.
It says another drug, Temazepam, the focus of the report, is used less commonly, with 88,700 prescriptions issued over the same period.
The report found the risk of death was four times higher among people using Temazepam compared to similar patients who were not taking the drug.
Pharmac medical director Dr Peter Moodie is taking a cautious view of the findings, saying it is difficult to draw a direct link between the medications and the deaths because it may be that people who take a lot of sleeping tables have other problems such as pain or depression.