The report, Cannabidiol oil in the treatment of super refractory status epilepticus is authored by Ian Rosemergy, Jonathan Adler and Alex Psirides and has been accepted for publication by a European journal.
It concludes the cannabidiol had "no effect" upon the underlying seizure illness and that medical staff observed no improvement in the patient's level of awareness, but it did help to facilitate his comfort.
"While the treatment was ultimately unsuccessful, we feel the use of the [treatment] was justified as it addressed an immutable need for the family who were forced to deal with a very tragic scenario."
Terminally ill former trade unions boss Helen Kelly has been arguing for the Government to include a referendum in the next general election in 2017 on whether cannabis should be legalised.
Ms Kelly, who has lung cancer, said the report showed the "impossibility" of the family sourcing the product by going through the motions and that if doctors were in charge of medical cannabis the system would have worked better and faster.
"But basically it shows that this product is useful and medical practitioners want to have access to it and ... the doctors think it is useful."
However, Mr Dunne said doctors were able to choose their patients' courses of treatment already.
"The fact they either choose not to or are slow to use such products reflects their clinical judgement. I cannot make them prescribe medicinal hemp or cannabis-based products, or any product for that matter, just because a patient wants it."
The only reason Mr Dunne's approval was required in Alex's case was because Elixinol was not currently approved for use in New Zealand.
Alex Renton's mother, Rose, said her son's treatment set a precedent for cannabis oil to be used as a medicine of choice for pain or in palliative care. "Alex would be proud we fought for New Zealand people's right to choose their own medicine. Dunne or anyone employed by in the Government are working for the people. The people are asking for a choice of medication in cannabis."
She said that before her son was even diagnosed, he was administered with 42 drugs before cannabis was an option. She disagreed with this logic.
"We should not have to be critical or dying to choose cannabis. That is wrong on so many levels."
Dr Rosemergy declined to comment until the report was published. Dr Adler and Dr Psirides could not be reached by the Weekend Herald.
Alex's story
April 2015: Alex Renton is admitted to Wellington Hospital after suffering from a prolonged seizure.
April-June 2015: Family lobby Government to approve use of Elixinol, a cannabidiol (CBD) product from the United States for Alex's treatment. His mother secretly administers it.
June 2015: Associate Health Minister Peter Dunne approves use of Elixinol.
July 1, 2015: Alex passes away.
January 6, 2016: Report on the treatment is accepted for publish in European medical journal.