I do the same thing Texarkana does. I set up my mother's pills before it is time to take them. If I see the pill bottle is empty, I know she took them. My mother took her medicines too often. They were making her sick, but did not want to give up control. It took me a couple of years and some angry battles before she would accept my help. Medicines are a major control issue for many elders.
I started setting up mothers pills 1 time a week in pill boxes a few years ago. I explained that its a much easier for both of us to keep track of what shes taken on any given day, and helps me know when to get a RX refilled. She doesnt have access to the vials just the day of the week boxes. She lives with me now, but when she was alone I got a recordable alarm clock to prompt her to check the day of the week and take her morning or evening pills.
I had to be very FIRM with my mother as she is on some very powerful meds. I did not ask her permission about using a pill box which I keep in my room where she can't get it. Since she is in MY house I will not allow an overdose or misuse of her drugs by her. I told her if she wanted to do that then she would have to live somewhere else. This responsibility gets put on me because she lives in my house. I put out her AM meds in her batheroom and after she eats breakfast and I see her take the pills I then put her PM pill in the bathroom 12 hours later, her pills are bid(twice a day).Sorry about her autonomy, dignity and all that good stuff. There are some things that can't be compromised and some of these pills,especially her hi dose morphine pill I will NOT leave up to her.Let her MIL get angry, her hair won't fall out and neither will yours, however what puts most seniors in the hospital is either taking to much of their meds, not enough of their meds, the wrong dosages at the wrong times, or in the wrong manner of taking them,like not with meals when they should. Meds can't be an area of compromise,period.Put your foot down, if she is living with you she could OD on them.This issue of elders having hissy fits about their meds is a real sore spot with me,(I am a nurse). I don't treat my mother like a child,she doesn't have dementia but she can be forgetful because of the morphine also she has no medical training in her whole life and doesn't "get " it about the seriousness of some of the meds she is on. I guess as a nurse I feel a greater responsibility that the meds are done correctly.Take the d*mn pill bottles away from her, I have may mother's stored in a place she can't get to them. The pill box I keep in my room . She got over getting angry and there have been no pill mishaps and no trips to the ER.
I don't think there is any way to know without counting. In my situation, the counting had to be done behind MIL's back because being openly involved her medicine is a serious trigger for her to get angry and argumentative.
We also tried to use the pill box and she would ignore it and take her pills from the bottles instead "Just like I always have!" *sigh*
Without knowing more, it sounds as though this person either needs to be left alone or needs supervision. My husband, who has no impairments, takes his heart meds from vials. My mom, who has dementia, is in a nh and has her meds administered by staff. Can your loved one be trusted to self administer? Are there memory issues?
We also tried to use the pill box and she would ignore it and take her pills from the bottles instead "Just like I always have!" *sigh*