Hi. My Mom Is 87 Years Old. She Takes Lisinopril,

Hi. My mom is 87 years old. She takes Lisinopril, Memantine and Donepezil. Today, she suddenly felt lightheaded and like she was going to collapse from weakness. I gave her an orange, then a bit of dinner. She isn't lightheaded, but says she feels weak everywhere. I also just noticed a small amount of yellowing in the outside corners of her eyes. Should I call her doctor, or take her to the ER? Or, can I just keep an eye on her to see if there is any change?