Cancer Patient with New York State, USA Medical Marijuana Card

We're at the early planning stages and I can't find an answer to my question.
My husband utilizes medical marijuana for pain management post cancer surgery.  It is legal in New York State and he has a state-issued card. 
Our plan is to fly from JFK in NYC to Dublin, have a self-drive vacation and fly back home out of Dublin. 

What restrictions are there for tourists who utilize medical marijuana arriving in and traveling through Ireland and departing?

I thank you for any help or guidance you may provide.

Hi Kathleen, 

Thanks for reaching out. 

Unfortunately, the general consensus is that you cannot travel to Ireland without encountering legal problems or having your medication taken off you, as you need a prescription from an Irish GP. The regulations around this are still very black and white, it could be worth contacting the US embassy in Ireland for more clarity on your situation. 

Cathaoir