No doctor in Australia can prescribe naltrexone for use using the Sinclair Method, because it is only approved for use in abstinence-based treatment. So, you will have to just agree to be abstinent to get the prescription, and then use it in the way you would like to.
I was able to get a prescription for Naltrexone from the GP that works out of the Drug Health unit at RPA Hospital in Camperdown:
http://wayahead.org.au/index.php/search ... h-servicesYou can just ring and make an appointment. They will get you to do some blood & Liver function tests as well probably. And all bulk billed. I imagine they have a similar system at St Vincents or probably most public hospitals.
Good luck!