New research has found paracetamol overdose is the most common form of drug poisoning, sparking calls for tighter controls on sales.
An audit found paracetamol accounted for 23 percent of medication poisonings in patients at Wellington Hospital between 2007 and 2012.
The main cause of paracetamol overdose in 2013 was deliberate self-harm and attempted suicide. Half of the patients were under 20, most of them girls.
The authors of the report, Nadia Freeman and Paul Quigley, say it's the most toxic over the counter substance we have in New Zealand and one of the things that can be done to reduce the risk is to keep the packet size smaller. They also suggest banning sales to under 18s.
New Zealand does not restrict the amount of paracetamol that can be purchased in pharmacies, and has a set limit of 10 grams per packet for all other outlet types, but there's no limit on the number of packets that may be purchased.
In the UK, sales are restricted to 16 grams per transaction in pharmacies and 8 grams for all other outlets.
While several studies have found no changes to suicides since the legislation was introduced in the UK in 1998, some studies have found a 20 percent reduction in paracetamol-related overdoses and a 22 percent reduction in deaths.
Clinical Director of Integrated Mental Health and Addictions at Middlemore Hospital, Dr Peter Watson, says that while limiting access to paracetamol is one thing we can do it's unlikely to make a difference to the number of suicide deaths in New Zealand.