But the safety regulator of the medicine in New Zealand says getting a new label on the drug could be an uphill battle.
Otago University student Freya Stephen died in November last year after taking methadone prescribed to her mother Denise Stephen following liver surgery.
The 19-year-old was already taking a pain relief drug, oxycontin, which she had taken for more than a year for chronic back pain stemming from a fractured spine.
Southern region coroner David Crerar found last month Miss Stephen died from an overdose.
There were no indications she had wanted to deliberately end her life. It appeared in taking the methadone she had genuinely been seeking pain relief, he said.
Mrs Stephen has already publicly warned of the dangers of oxycontin, a highly addictive drug from the same family as morphine, codeine and heroin.
Now she, with the support of husband John Stephen, has written to New Zealand medicine safety watchdog Medsafe asking for a warning label to be added to methadone prescribed for analgesic purposes.
"It needs to have a very large label saying 'Do not take this medication with any other pain relieving medication. Consult your doctor first.' If [Freya] had seen such a warning on the bottle, would she have taken any at all?"
One young death was too many, Mrs Stephen said.
"Out of her death has to come some change. If I can get this change made it may save a life. I do not want any other mother to suffer as much as I am."
There was no doubt her daughter had broken a basic rule when she took someone else's prescription medicine, Mrs Stephen said.
"Freya shouldn't have taken it. But she did not know what might happen. She took such a small amount, she did not know she had to ask."
A Medsafe spokesman said their primary message would be that prescription medicines should only be taken by the person they have been prescribed for, in conjunction with advice from that person's health professional.
Changing labels on medication was a battle, but it could be done, he said.
It was unusual, but members of the public could make a submission to Medsafe regarding the labelling of products and consideration would be given to the need for changes to labels or other actions.
Although the legislation specified certain information must be present, Medsafe did not object to the presence of additional labelling statements, such as warning statements, provided those statements were correct, not confusing or misleading and of benefit to the consumer.
Generally, requests to change labels must be submitted by the medicine licence holder - in tjhe case of metha-done, one of several Auckland-based sponsors.
Where there was a serious safety issue, Medsafe would contact the licence holder and request changes to labels, but could not compel them to do so.
Ultimately, if a company refused to make a safety-related change Medsafe would have to consider whether consent for the medicine should be revoked, the spokesman said.
