You can get tetracyline at most feed stores (for horses, same stuff they give to people), but you'll have to find out the dosage and get gel caps at the health food store for it. Very inexpensive. I have 6 bags in the freezer.
If you go looking around on the Internet, you can find stuff like Keflex for fish tanks, again, same stuff, but you'll have to figure out dosages for humans. MUCH less expensive than a scrip.
I have to use a sleep medication that I buy from India (the stuff is made in Canada). It costs me $17 for 5 pills here in the States, and I get 90 of them from Noble Drug in India for $36, including shipping, and no doctor visit ($60) for a scrip...you might check them out, I think it's nobledrug.com. And I have not had any trouble with them getting here. And isn't that some crap...I have to buy Canadian drugs via India...WTH...is America Big Pharm's cash cow, or what?