AITB for proving my roommate were stealing my pain meds

I have a few serious medical condition that require me to take medications just to stay alive. Most of meds are not narcotic. But I do have a strong take as need pain med for one of my condition that’s cause flair up that send shock wave of pain through out my body that can last for hours

The issue is I just moved into a new apartment two month back and I have two roommate who seem nice enough at first but we’re also daily drug users.

I seen them smoking weed and some kind of pills.

I didn’t think much of it as it there life but then I started noticing my own pain med going missing.

When I ask them they denied it. After the first time I ask I let it go figured they would stop now that I had confronted them but they didn’t.

Because of the strength of this pill I’m limited to how many I can get so someone stealing them could end up with me not having them when I need them.

I had no prove they were stealing them so I tried something

One morning before I left for work I switch out my medications for a strong laxative pill I have as my medications I take tend to back me up. They look similar to my pain meds. I put them back in the cabinet and left.

When I got home both roommates were in the bathroom. It was clear they took the pills.

I ask what was wrong and they just played it of as being sick. And didn’t say much else.

But the next day I get a call from one of there sister who berated me for “ poisoning her brother” telling me I went to far.

But I never force them to take them so I’m not sure how I’m the bad guy.

Edited: No I can not face legally trouble for this. As they stole the med I didn’t give or force them to take them. They broke into my room to get them, We do not share a bathroom. I have mine own in my room which I keep locked they are in my med cabinet which they have no business being in, they are aware of my medical issue and the med I take so they is no excuse for randomly taken med from my room. No they couldn’t have taken them by mistake as the bottle is clear mark in big print. Even if they did try to lie and say I gave them to them These are active drug user who can’t go a day without getting high. They have past charge for possession as well as some assault charges. So even if they lied I pretty sure my statement will have more creditability. Plus they try to take this to court they will be drug tested.

Edit 2: Again this nit a legal question I know for fact There really nit much they can do without pretty much getting themselves in even more trouble then I would,

I’m not asking if I’m legally in the wrong as I know I’m am this is a moral question

AITB for proving my roommate were stealing my pain meds