I have to give you another opinion on this.
I am a UK doctor and for the last 16 years I have been working in hospices where morphine is used virtually daily.
You can drink moderate alcohol on MST by which I mean a glass of wine with a meal 2 or 3 times a week (or a pre meal sherry or 1 beer.)
We allowed our patients to have alcohol at the hospice (irrespective of the dose of morphine they were on) but moderation, as always, is the key. In fact we had a drinks trolley that went round each evening.
The following link to the UK MacMillan site goes into a lot of detail about painkillers in general but under "Side Effects of Strong Opioids" you will find the current guidance on alcohol intake whilst on opioids.
This is what it says:
and here is the link to the whole article:
This is the guidance we observed at the hospice.
Hope that helps,
I am a caring and compassionate UK doctor and have been qualified for 23 years. I have widespread experience in GP and cancer care.