Clinical Pharmacology 2000
http://cp.gsm.com/apps/default.asp?entry=&rNum=943
Subject: FQ Toxicity & Caffeine

Note below what it says about caffeine and quinolone TOXICITY.
". Caffeine or theophylline toxicity can result and can manifest as
nausea/vomiting, nervousness, anxiety, tachycardia, or seizures. This interaction is dose-dependent "
Caffeine and Ciprofloxacin
Enoxacin and, to a lesser extent, ciprofloxacin, grepafloxacin,
levofloxacin, and norfloxacin decrease the clearance of caffeine. Not all quinolone antibiotics have this effect on caffeine
pharmacokinetics, however. Exaggerated effects of caffeine would be expected if the pharmacokinetics of caffeine were affected.
Ciprofloxacin reduces the hepatic clearance of caffeine and
theophylline. The effect of ciprofloxacin is less than that of enoxacin but more significant than that of norfloxacin. Caffeine or theophylline toxicity can result and can manifest as nausea/vomiting, nervousness, anxiety, tachycardia, or seizures. This interaction is dose-dependent (i.e.,higher doses of ciprofloxacin produce more significant inhibition). The elderly and individuals who consume large amounts of caffeine-containin beverages should receive particular attention.

Caffeine and Levofloxacin
Enoxacin and, to a lesser extent, ciprofloxacin, grepafloxacin,
levofloxacin, and norfloxacin decrease the clearance of caffeine. Not all quinolone antibiotics have this effect on caffeine
pharmacokinetics, however. Exaggerated effects of caffeine would be expected if the pharmacokinetics of caffeine were affected.
Finally, since some quinolones can inhibit the hepatic clearance of
caffeine, caffeine-containing beverages should be minimized while
taking this antibiotic.