I would suggest, that if it will make you feel more comfortable, go ahead and lock up your meds.
He may not use anything you are taking, but could sell on the street to get what he wants.
I personally, when I have sponsees coming over, make sure that my meds are locked up. I do have some that would sell well on the street and/or could be used by a sponsee if the sponsee was so inclined. I am a recovering alkie for many years now and almost as long in Alanon.
I take care of ME today. I cannot worry or look after the alkies and/or addicts in my life, however, I can prevent them 'using' me to get to their DOC.
Your choice.
J M H O
Love and hugs,