If you don't have insurance , just tell your pharmacy you are self pay. you don't need insurance to buy medicine as long as you have a prescription from your MD. This is how I brought my mom's med in the past 5 years at Walmart and CVS. ( walmart is the cheapest so far) About the ER issue, trust me if you need to go er just go. your parent wont' be the first or last person in ER with no insurance. In fact there is a good number of patients are uninsured or illegal immigrants because they are the group of patients who will prolong seeking medical help until they are getting worst.
I work at the the hospital as RN for 10 yrs. I know there is a good amount of federal found pay to the hospital just to cover these expands. Most of the time if they know you are self pay , you will get discount . I paid 240 for my mom's ER bill which worth over $700. Well, if they need surgery or need to be admitted to the hospital, then that will be a difference story. That will be costly even after discount.