Enoxacin: a new fluoroquinolone

The chemistry, mechanisms of action and resistance, pharmacokinetics, antimicrobial spectrum, clinical efficacy, adverse effects, and drug interactions of enoxacin are reviewed. Enoxacin is a new fluoroquinolone compound structurally related to nalidixic acid. Its antimicrobial spectrum and activity are comparable to those of the fluoroquinolones norfloxacin and ciprofloxacin. It has a broad spectrum of activity against gram-negative and gram-positive microorganisms, but like the other fluoroquinolones it is less active against gram-positive micro-organisms. Anaerobic organisms are generally resistant to enoxacin. It is rapidly and nearly completely absorbed after oral administration and is distributed widely in body fluids and tissues. The drug is predominantly excreted via the kidney, with a relatively long serum elimination half-life of approximately five hours. Serum and urinary concentration of enoxacin exceed the minimum inhibitory concentrations for most gram-negative and many gram-positive pathogens. Clinical trials have shown enoxacin to be effective for the treatment of gonorrhea, cystitis, complicated urinary-tract infections, and skin and skin structure infections. There is some evidence that enoxacin may be useful for treatment of lower-respiratory-tract infections and ear, nose, and throat infections. The most commonly reported adverse effects are mild gastrointestinal and central nervous system symptoms. Concomitant enoxacin and theophylline therapy has been associated with toxic serum concentrations of theophylline. Interactions have also been reported with caffeine, antacids, cimetidine, warfarin, and fenbufen. Enoxacin (Comprecin, Parke-Davis/Warner-Lambert) will be available in 200-, 300-, and 400-mg tablets for oral administration. Enoxacin is usually taken twice daily. A single 400-mg dose is effective therapy for uncomplicated gonorrhea. Since enoxacin, ciprofloxacin, and norfloxacin have many similar properties, formulary decisions involving these agents should be based on the individual institution's need to treat certain types of infections and pathogenic organisms. Enoxacin has been shown to be an effective agent for the treatment of urinary-tract, genital-tract, and skin and soft-tissue infections, including those that currently require injectable antimicrobial agents or that are resistant to conventional therapy.