ANTIMICROBIAL ACTIVITY OF HUMAN PANCREATIC-JUICE AND ITS INTERACTION WITH ANTIBIOTICS

Pancreatic juice (PJ) should be a factor of variability in the antimic robial activity of antibiotics eliminated by the pancreas during pancr eatic infections, We studied its effects on the activity of antimicrob ial drugs with different mechanisms of action, Samples of pure PJ were collected from 16 patients with stabilized external pancreatic fistul as, The antimicrobial activity of the juice at different concentration s (from 1.25 to 100%) alone and in combination with mezlocillin, imipe nem, ceftriaxone, gentamicin, ofloxacin, and ciprofloxacin was studied by a microbiological method (continuous turbidimetric recording of ba cterial growth), The human PJ showed dose-dependent antimicrobial acti vity that increased directly with the concentration, The activity of t he antibiotics at bactericidal concentrations were not modified by the PJ, while the combination with subinhibitory concentrations produced the following variable and different effects: (i) additivity with mezl ocillin, ceftriaxone, gentamicin, and ciprofloxacin and autonomy (no i nteraction) with imipenem and ofloxacin against Providencia rettgeri a nd (ii) additivity with ceftriaxone, ofloxacin, gentamicin, imipenem, and mezlocillin and autonomy with ciprofloxacin against Escherichia co li, In the presence of PJ, fluoroquinolones showed constant positive e ffects, while beta-lactams showed more variable antimicrobial activity , Antibiotic concentrations and PJ pharmacodynamics are the main facto rs determining the final effect of the interaction in vitro, These res ults may be useful in choosing antibiotics for the treatment of pancre atic infections when they are supplemented ,vith the pharmacokinetic d ata for each drug.