Minimal inhibitory concentrations (MIC) of
enoxacin,
nalidixic acid,
pipemidic acid,
norfloxacin,
ciprofloxacin,
ofloxacin and
pefloxacin against isolates from 400 urological in-patients with complicated
urinary tract infections (UTI) were determined by means of an
agar dilution technique (10(4) cfu, multipointer). 28 patients (21 male, seven female) aged 36 to 84 years with complicated UTI due to sensitive bacteria were treated orally with 200 mg
enoxacin b.i.d. for six to 14 days. Plasma and urine samples were collected from 19 patients, at intervals prior to and following a 400 mg dose of
enoxacin, and
enoxacin concentrations were determined by a high pressure liquid chromatography (HPLC) method. The MICs of
enoxacin against all but one of the gram-negative isolates cultured from 265 urological patients were between 0.03 and 4 mg/l. The MICs against 134 gram-positive isolates were between 0.25 and 16 mg/l except two strains of streptococci. At a concentration of 4 mg/l (8 mg/l), 90.3% (98%) of the total spectrum of isolates were inhibited by
enoxacin. Of the
quinolones tested,
ciprofloxacin appeared to be the most active compound in vitro and
cinoxacin the least active
antimicrobial agent. The in vitro activity of
enoxacin was comparable to that of
norfloxacin,
ofloxacin and
pefloxacin.
Oral administration of 400 mg
enoxacin to elderly patients resulted in peak serum concentrations between 0.7 and 6.3 mg/l (mean 3.6 mg/l) attained between 1.0 and 6.0 h following
drug ingestion. The mean urinary recovery of parent
drug within 24 h was 31.2% of the administered dose. 25 of 28 patients treated orally with
enoxacin could be followed-up for five to 14 days after the end of treatment.
Enoxacin therapy in these patients resulted in 18 cures, one failure and six relapses (same species). The
drug was well tolerated and there was no evidence of renal, hepatic or haematological toxicity.
Enoxacin appears to be well suited for the treatment of complicated UTI.