INFLUENCE OF INTRAVENOUSLY ADMINISTERED CIPROFLOXACIN ON AEROBIC INTESTINAL MICROFLORA AND FECAL DRUG LEVELS WHEN ADMINISTERED SIMULTANEOUSLY WITH SUCRALFATE

Ciprofloxacin, when given intravenously (i.v,), is secreted in signifi cant amounts via the mucosa into the intestinal lumen, Sucralfate inhi bits the antimicrobial activity of ciprofloxacin, The effect of combin ed therapy on the intestinal flora was investigated in 16 healthy volu nteers, They were randomly assigned to two groups, Group A received 2 g of sucralfate orally three times a day for 7 days and 400 mg of cipr ofloxacin i,v, twice a day (b,i,d,) starting 3 days after the sucralfa te administration began, Group B was given only 400 mg of ciprofloxaci n i,v, b.i,d, for 4 days, A total of 9 stool samples were collected fr om each subject beginning the week before ciprofloxacin was administer ed and on days -1, 1, 2, 3, 4, 7, 9, and 10 or 11 after commencement o f the infusion period, The aerobic fecal flora was determined by stand ard microbiological methods, Measurements of fecal ciprofloxacin level s were based on high-performance liquid chromatography, Counts of bact eria of the family Enterobacteriaceae decreased in all subjects and we re below 10(2) CFU/g in eight of eight subjects (group A) and six of e ight subjects (group B) on day 4, but they returned to normal in all b ut one subject (group A) 10 days after the last infusion, The decrease s in levels of bacteria of the family Enterobacteriaceae were not sign ificantly different in groups A and B (Kaplan-Meier test), Staphylococ ci and nonfermenters responded variably, enterococci and lactobacilli remained unchanged, and candida levels increased transiently in four s ubjects (two in each group), Maximum fecal drug levels ranged from 251 to 811 mu g/g No significant difference could be found between the tw o groups, The i,v, application of ciprofloxacin eliminates intestinal bacteria of the family Enterobacteriaceae in a rapid and selective man ner. This effect is not affected by simultaneous oral application of s ucralfate.