title: Antimicrobial activity of human pancreatic juice and its interaction with antibiotics.
abstract: Pancreatic juice (PJ) should be a factor of variability in the antimicrobial activity of antibiotics eliminated by the pancreas during pancreatic infections. We studied its effects on the activity of antimicrobial drugs with different mechanisms of action. Samples of pure PJ were collected from 16 patients with stabilized external pancreatic fistulas. The antimicrobial activity of the juice at different concentrations (from 1.25 to 100%) alone and in combination with mezlocillin, imipenem, ceftriaxone, gentamicin, ofloxacin, and ciprofloxacin was studied by a microbiological method (continuous turbidimetric recording of bacterial growth). The human PJ showed dose-dependent antimicrobial activity that increased directly with the concentration. The activity of the 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 mezlocillin, ceftriaxone, gentamicin, and ciprofloxacin and autonomy (no interaction) with imipenem and ofloxacin against Providencia rettgeri and (ii) additivity with ceftriaxone, ofloxacin, gentamicin, imipenem, and mezlocillin and autonomy with ciprofloxacin against Escherichia coli. In the presence of PJ, fluoroquinolones showed constant positive effects, while beta-lactams showed more variable antimicrobial activity. Antibiotic concentrations and PJ pharmacodynamics are the main factors determining the final effect of the interaction in vitro. These results may be useful in choosing antibiotics for the treatment of pancreatic infections when they are supplemented with the pharmacokinetic data for each drug.
authors.affiliation: Institute of Pharmacology, University Hospital, University of Verona, Italy.
authors.forename: E B
authors.initials: EB
authors.lastname: Minelli
authors.forename: A
authors.initials: A
authors.lastname: Benini
authors.forename: C
authors.initials: C
authors.lastname: Bassi
authors.forename: H
authors.initials: H
authors.lastname: Abbas
authors.forename: M
authors.initials: M
authors.lastname: Falconi
authors.forename: F
authors.initials: F
authors.lastname: Locatelli
authors.forename: R
authors.initials: R
authors.lastname: de Marco
authors.forename: P
authors.initials: P
authors.lastname: Pederzoli
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000890:Anti-Infective Agents / Q000494:pharmacology; D004347:Drug Interactions; D004926:Escherichia coli / Q000187:drug effects* / Q000254:growth & development; D005260:Female; D024841:Fluoroquinolones; D006801:Humans; D007769:Lactams; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D010189:Pancreatic Juice / Q000502:physiology*; D011532:Providencia / Q000187:drug effects* / Q000254:growth & development
chemical_list: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D024841:Fluoroquinolones; D007769:Lactams