Enoxacin, a new fluoroquinolone antibiotic, is rapidly and extensively absorbed after oral administration and has a bioavailability independent of dose and only slightly delayed by concurrent food. Plasma concentrations are similar for both intravenous and oral administration. The t1/2 for enoxacin ranges from 4 to 6 hours, which allows effective twice-daily administration without significant accumulation. Plasma enoxacin concentrations may be slightly higher in elderly subjects, but this change does not necessitate dosage adjustment in older patients with adequate renal function. Enoxacin and ciprofloxacin decrease the clearance of coadministered theophylline, whereas ofloxacin does not appear to greatly alter methylxanthine clearance. Maalox (a magnesium-aluminium hydroxide antacid) significantly decreases the oral bioavailability of ciprofloxacin, ofloxacin and enoxacin, and use of these agents with antacids should be avoided. Enoxacin is a highly effective oral anti-infective agent with excellent bioavailability characteristics, a relatively slow rate of elimination and simple, well-defined requirements for dosage modification in patients with renal dysfunction.