system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: If generic brands for prescriptions exist, why do the name brands not get taken off the shelf due to price, or are sold at all?
gpt
Because sometimes there's considerable differences in the brand over the generic brands. One of the ones that comes immediate to mind is Panadol (Tylenol if you're American). You can buy the cheapo generic brands by they are general large, chunky tablets that get easily stuck in your throat, hurt and taste very bad. The brands usually have capsules, or least easier to swallow tablets, and generally have a coating that doesn't make it taste extraordinarily bad. 

Another reason is because, although the ingredients are pharmaceutically identical, they may not trust 'generic' versions (after all it is your health you're dealing with). The power of suggestion and especially that more money must equal a better product means that people simply won't settle for a generic brand. Even if it's just a snobby preference. 

Lastly, they just may not understand the difference. The doctor might have written a prescription for Panadol, and so that's what they *have* to get. They're Doctor knows best, so they don't want to take the risk.