Scary incident with Rivastimine

My DH uses a patch daily of Rivastimine because he had upset stomachs taking Aricept. He usually takes a shower before bedtime and I always ask him if he put on his patch. Over half the time he didn’t remember so he goes back in the bathroom and puts it on. Yesterday he got up and didn’t feel well all day. He could barely get out of bed and said he felt like something was wrong with his heart. I took his blood pressure, which was fine but his pulse was 44 and very weak. I was on the verge of calling 911, but by chance discovered that he had put on 2 patches. I removed one and he went to bed. The next morning he got up feeling fine and didn’t remember anything about the day before. Luckily I found the problem. I had messaged his doctor when all this happened but then had to message again that he was ok.