That correspondence reveals widespread support - but also some misgivings.
"The elephant in the room is perpetuated by this new regime," Professor Doug Sellman of the National Addictions Centre said in a June 5 email.
"It is quite possible that new recreational drugs that have less impact than alcohol on public health will be eliminated.
"Any recreational drug policy that doesn't include alcohol is a farce. But you know that already."
Environmental Science and Research bioanalytical programme manager Dr Paul Fitzmaurice made his point in a February 17 email.
"If the government is accepting of the higher harm associated with alcohol and tobacco, then the applying of a different metric to new substances would imply that the current legislation is incorrect."
In reply, ministry policy analyst Mark Heffernan wrote that he would be "uneasy" about aligning the safety tolerance factor with alcohol, "due to the substantial harm that alcohol can cause".
"This would be a hard sell and I think it will be necessary to set the bar for approval at a level that alcohol would not meet."
The documents also reveal that synthetic cannabis is unlikely to be approved in smokable form because of concerns about cancer and dosage.
But other drugs, including hallucinogens, could be deemed "low risk" and on sale by around 2014.
The Ministry of Health rejected one unnamed health professional's advice that hallucinogens should be automatically rejected.
It noted that experts, including former British Government adviser Professor David Nutt, had identified LSD as low-risk compared to other recreational drugs.
"A challenge we will face therefore is what happens should an 'LSD like' drug be submitted for approval under the proposed new regime," Mr Heffernan wrote in a February 8 email.
"If this product's potential to induce hallucinations immediately led to the abandonment of a trial, then the true harm of such a substance, which could in theory be relatively low, will be difficult to ascertain."
Officials at Mr Dunne's office could not be reached for commentyesterday.
But NZ Drug Foundation executive director Ross Bell said there were inconsistencies in society's approach to alcohol.
"This hypocrisy that we have in the policy frameworks is seen very starkly by young people.
"Parents are saying the drug that you smoke or the pills that you take are terribly bad.
"But the drink that I can buy from the supermarket that causes billions of dollars more damage is okay."
But he said political realities meant a "one size fits all" drug policy was not likely, and the psychoactive-drug reforms should be applauded.
"The Government has turned away from the sledgehammer of prohibition, to recognising it can take greater control over that part of the drug market."
Alcohol Action NZ spokesman Dr Geoffrey Robinson said alcohol was a huge cost for hospitals and emergency departments.
"Most hospital departments have got some alcohol-related problems, whether it's the brain, the liver, pancreas or cardiac problems."
Dr Robinson said there was also a direct cost to the public health system from treating injuries that resulted from alcohol-fuelled violent assaults.
He said legal-system costs from alcohol-related issues were also substantial.
