Erythromycin, Tetracycline and quite a few others will not be available over the counter soon.
Eventually they'll end up doing the same with all antibiotics and dewormers for livestock and fish. Better get anything you need while you can. I used doxycycline for COVID. Ivermectin too.
I stocked up on a full range of antibiotics, especially amoxicillan, which is in short supply where I live.
List of where to buy:
https://patriots.win/p/16bP7guA5N/sources-for-ivermectin—hcq-anti/