I know that they should supply your prescription for your normal medications. When a family member went to jail for a week they did not supply her with her medication for her bi-polar condition. She has a bi-polar condition that if she doesn't regularly take her medication she is at risk for a psychotic break.
They weren't concerned about that. If she had been on high blood pressure medication I wonder if they would have given her that. Probably. So, I think they only give you medication that without it it could be life threatening. I don't think that if you are without marijuana that that would be deemed as life threatening.
Also, although marijuana in some states is legal on a federal level it is still illegal.