How does drinking alcohol affect your antibiotics?

Depends on which: antibiotic. There are many drug interactions with alcohol, since it enhances the liver enzymes that metabolize not only alcohol (one of the factors leading to tolerance) but many other drugs, including ciprofloxacin and similar antibiotics. Moreover, alcohol decreases activity of both kinds of white blood cells - those producing antibodies and those that eat up (phagocytize) bacteria/viruses.