Sera Chews
She also believes that if Miles was on the tramadol, he would be sleeping in bed, not eating or possible dead instead of running on the beach and being himself which he is now doing. Miles had terminal cancer and would die soon, Sera Chews was the reasoning Denis turned to when she felt hesitant about giving Miles an unapproved drug. She further reasoned by saying people don't overdose on marijuana and is used on humans suffering pain and nausea from cancer and cancer treatment.
http://www.umbsstudio.com/sera-chews/