Anaesthetists have warned MPs that any major widening of powers to prescribe medicines could open a Pandora's box of problems.
They told Parliament's health select committee on Wednesday that some planned changes to medicines laws are confusing.
The Medicines Amendment Bill updates and expands the range of health workers who may prescribe medicines and under what circumstances.
The bill adds nurse practitioners and optometrists to those who can currently prescribe medicines such as doctors, dentists and midwives.
The Society of Anaesthetists said they deal with potentially dangerous drugs and are acutely aware of the potential for harm if drugs are not used cautiously and correctly.
They said they appreciate that under some circumstances some drugs may be prescribed safely by people who lack medical training.
However, they said widespread prescription of multiple drugs by inadequately trained people working outside their area of expertise could cause complications, side-effects, toxicity, costs and drug resistance.
Midwives want to prescribe extra pain drugs
Midwives want to be able to prescribe two extra pain relief drugs for women in labour to improve the wellbeing of babies.
The Midwifery Council and the College of Midwives appeared before the select committee to offer their views on the proposed bill.
The council said midwives can only prescribe Pethidine for pain relief in labour, but it can affect new-born behaviour.
A council member, Marion Hunter, said Pethidine can cause sleepiness in babies in the first three or four days of life, inhibiting feeding, and midwives want to be able to use Morphine or Fentanyl instead to protect mothers and infants.
The council says it supports midwives having prescribing rights only for the controlled drugs within their scope of practice.
