They're pretty common. I had a sinus infection earlier this year that wouldn't go away and had to get some antibiotics. I picked up the RX from a local Walmart pharmacy (closer to where I live) and they use the same double-sided caps.

But again, it's like the other OP said: The childproof side is the one that they put on first which could present an issue for older people. I'd imagine you could ask them not to do that, though. I never really thought about it.

They often look like this, note the threads on the top of the cap, they can be flipped over and used as a simple threaded cap with no child lock:

https://upload.wikimedia.org/wikipedia/commons/3/31/Walgreen...