Ciprofloxacin penetration in pancreatic juice

Selective and Concentrative Enteropancreatic Recirculation of Antibiotics by Pigs

Antibiotics that are efficacious for infectious pancreatitis are present in pancreatic exocrine secretion (PES) after intravenous administration and above minimal inhibitory concentrations. We measured concentrations of four antibiotics by tandem liquid chromatography-mass spectroscopy in plasma and PES after enteral administration to juvenile pigs with jugular catheters and re-entrant pancreatic-duodenal catheters. Nystatin, which is not absorbed by the intestine nor used for infectious pancreatitis (negative control), was not detected in plasma or PES. Concentrations of amoxicillin increased in plasma after administration (p = 0.035), but not in PES (p = 0.51). Metronidazole and enrofloxacin that are used for infectious pancreatitis increased in plasma after enteral administration and even more so in PES, with concentrations in PES averaging 3.1 (±0.5)- and 2.3 (±0.6)-fold higher than in plasma, respectively (p's < 0.001). The increase in enrofloxacin in PES relative to plasma was lower after intramuscular administration (1.8 ± 0.5; p = 0.001). The present results demonstrate the presence of a selective and concentrative enteropancreatic pathway of secretion for some antibiotics. Unlike the regulated secretion of bile, the constitutive secretion of PES and intestinal reabsorption may provide a continuous exposure of pancreas tissue and the small intestine to recirculated antibiotics and potentially other therapeutic molecules. There is a need to better understand the enteropancreatic recirculation of antibiotics and the associated mechanisms.

[Antibiotic therapy in acute pancreatitis]

Infected pancreatic necrosis (IPN) is one of the main causes of mortality in patients with acute pancreatitis (AP). The choice of antibiotic therapy in AP should be based on penetration of the drug in the pancreas and the degree of coverage provided against the typical bacterial flora produced in IPN. Drugs such as imipenem, ciprofloxacin and metronidazole have been widely studied and seem to be ideal in the treatment of INP. Clinical practice guidelines recommend a carbapenem agent as the initial empirical treatment. When Gram-positive pathogens are isolated in pancreatic samples, vancomycin can be used alone or associated with a carbapenem. Currently, prophylactic antibiotic therapy for IPN is not supported by the scientific evidence, since both the best quality studies (double-blind) and the latest meta-analysis published have found no benefit of the use of this strategy.

The role of antibiotic prophylaxis in the treatment of acute pancreatitis

Acute pancreatitis is an inflammatory disorder, but it is not generally caused by infectious agents. Yet, in tertiary referral hospitals, the majority of patients who die of necrotizing pancreatitis do so as a consequence of infectious complications. These generally develop late (2-4 weeks) in the disease process. This finding prompted the hypothesis that infectious pancreatitis complications, such as an abscess or an infected necrosis which can lead to death, can be reduced by treating patients who suffer, at least initially, from a sterile inflammatory disorder, with broad-spectrum antibiotics. Here we review the experimental foundations of this hypothesis, as well as the difficulties that were encountered when clinical trials were undertaken to confirm it. At present, there is still a case for treating necrotizing pancreatitis patients with broad-spectrum antibiotics (specifically carbapenems), but the extent of the beneficial effect and the number of patients expected to profit from this approach should not be overestimated.

The role of antibiotic prophylaxis in the treatment of acute pancreatitis

Infected necrosis in acute pancreatitis is one of the most dreaded complications of acute pancreatitis. Whereas selection of an appropriate antibiotic treatment of the infection poses no problem, prophylactic application of antibiotic remains controversial in the absence of symptoms of infection, but where contrast-enhanced CT scan clearly proves necrosis. This article discusses the present state of the art of the role of antibiotic prophylaxis in the treatment of acute pancreatitis and provides clinical guidelines.

Prophylactic antibiotics for severe acute pancreatitis: the beginning of an era

Death from acute severe pancreatitis results from infection and multiple organ system failure occurring late in the course of illness. Patients with necrotizing pancreatitis involving at least one-third of the organ are at highest risk of secondary infection and death. We conducted a MEDLINE search to identify human trials of prophylactic antibiotics in acute pancreatitis. Results of early studies of prophylactic ampicillin to avoid secondary infection and death were negative, but the studies included patients with mild disease who are at low risk for infection. Antibiotics were beneficial in four recently completed studies: imipenem significantly reduced pancreatic and nonpancreatic sepsis (p< or =0.01); cefuroxime reduced all infectious complications (p<0.01) and deaths (p=0.0284); a regimen of ceftazidime, amikacin, and metronidazole reduced all infectious complications (p<0.03); and protocol use of imipenem significantly reduced pancreatic infection compared with nonprotocol antibiotics (p=0.04) and no antibiotics (p<0.001). Based on these results, we suggest early antibiotic prophylaxis in patients with necrotizing pancreatitis, but the best drug and duration of therapy are unknown.

Penetration of antibiotics into the pancreas in rats: an effect of acute necrotizing pancreatitis

BACKGROUND

Penetration of antibiotics into the pancreas is considered to be an important criterion in determining the most appropriate antibiotic treatment during severe acute pancreatitis. Our study investigated pancreatic penetration of five antibiotics in rats with and without acute necrotizing pancreatitis (ANP) (non-pancreatitis rats (NR), pancreatitis rats (AP)).

METHODS

ANP was induced by intraductal bile acid injection, and 3 h later the antibiotic was administered. In both NR and AP the antibiotic concentrations were evaluated in blood and pancreatic tissue 90 min after antibiotic administration.

RESULTS

The tissue/serum (T/S) ratios for NR were 16% with amikacin, 24% with amoxycillin/clavulanic acid, 27% with piperacillin, 59% with ofloxacin, and 108% with cefoperazone. The ratios for AP were 7%, 23%, 26%, 52%, and 70%, respectively. T/S ratios were similar for NR and AP except for amikacin, for which the T/S ratio was lower in AP than in NR (P = 0.02). Pancreatic tissue concentrations of antibiotics with high penetration rates (cefoperazone and ofloxacin) were sufficient to inhibit most of the pathogens expected during acute pancreatitis. The concentrations of the other antibiotics were less than the minimal inhibitory concentrations (MIC) for common potential pathogens in pancreatic infection.

CONCLUSIONS

Cefoperazone and ofloxacin showed the best pancreatic penetration of the five antibiotics tested. The high concentrations of these antibiotics in the pancreatic tissue would have enabled efficient antibacterial activity against most of the potential pathogens causing pancreatic infection. An early stage of acute necrotizing pancreatitis did not have a major effect on the pancreatic concentrations of the antibiotics.

Intra-abdominal Candida infection during acute necrotizing pancreatitis has a high prevalence and is associated with increased mortality

OBJECTIVES

To analyze the frequency of intra-abdominal Candida infection during acute necrotizing pancreatitis and to compare the outcome to patients without Candida infections.

DESIGN

Retrospective analysis of data from 37 patients with and without Candida infection.

SETTING

Surgical intensive care unit (ICU) in a university hospital.

PATIENTS

Thirty-seven patients with acute necrotizing pancreatitis.

INTERVENTIONS

Patients were subject to necrosectomy and programmed lavage.

MEASUREMENTS AND MAIN RESULTS

Clinical parameters contained in the Acute Physiology and Chronic Health Evaluation (APACHE) II score were monitored, as were microbiological results from the intra-abdominal primary focus and from sites of secondary infections. Body mass index, distribution of underlying diseases, length of ICU stay, number of operations, and outcome were recorded. Multivariate logistic regression analysis for mortality as the dependent variable was performed. Intra-abdominal Candida infection was observed in 13 of 37 cases and was associated with a four-fold greater mortality rate compared with intra-abdominal bacterial infection alone. Multivariate logistic regression analysis demonstrated that Candida infection contributed to mortality significantly (p < .025) and independently from APACHE II (p < .006; mortality odds ratio for the two parameters=12.5). Lack of antimycotic treatment was associated with an increase to 29.2 (p<.001) in the odds ratio.

CONCLUSIONS

Given the impact of Candida infection on mortality to acute necrotizing pancreatitis and the apparent benefit from antimycotic chemotherapy, the data argue for an early fungicide chemotherapeutic intervention.

Antimicrobial activity of human pancreatic juice and its interaction with antibiotics

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.

Penetration of ciprofloxacin into the human pancreas

The aim of this study was to determine the concentrations of ciprofloxacin in human pancreatic tissue and juice. Concentrations were measured by high-pressure liquid chromatography (HPLC). Two hundred mg of ciprofloxacin were administered as a short i.v. infusion (30 min). The median ciprofloxacin concentrations 140 min (median) after the start of infusion in pancreatic tissue as well as in pancreatic juice were 0.9 mg/kg (mg/l). The penetration ratio was 1.0 for pancreatic tissue and 0.83 for pancreatic juice. With regard to the minimal inhibitory concentrations (MIC) for the respective bacteria, ciprofloxacin seems to be an appropriate drug for the treatment of septic complications in necrotizing pancreatitis. Future clinical trials are necessary to prove this assumption.

Behavior of antibiotics during human necrotizing pancreatitis

The aim of the study was to verify whether antibiotics excreted by the normal pancreas are also excreted in human necrotizing pancreatitis, reaching the tissue sites of the infection. Twelve patients suffering from acute necrotizing pancreatitis were treated with imipenem-cilastatin (0.5 g), mezlocillin (2 g), gentamicin (0.08 g), amikacin (0.5 g), pefloxacin (0.4 g), and metronidazole (0.5 g). Serum and necrotic samples were collected simultaneously at different time intervals after parenteral drug administration by computed tomography-guided needle aspiration, intraoperatively, and from surgical drainages placed during surgery. Drug concentrations were determined by microbiological and high-performance liquid chromatography assays. All antibiotics reached the necrotic tissues, but with varying degrees of penetration, this being low for aminoglycosides (13%) and high in the case of pefloxacin (89%) and metronidazole (99%). The concentrations of pefloxacin (13.0 to 23 micrograms/g) and metronidazole (8.4 micrograms/g) in the necrotic samples were distinctly higher than the MICs for the organisms most commonly isolated in this disease; the concentrations in tissue of imipenem (3.35 micrograms/g) and mezlocillin (8.0 and 15.0 micrograms/g) did not always exceed the MICs for 90% of strains tested, whereas the aminoglycoside concentrations in necrotic tissue (0.5 microgram/g) were inadequate. Repeated administration of drugs (for 3, 7, 17, and 20 days) seems to enhance penetration of pefloxacin, imipenem, and metronidazole into necrotic pancreatic tissue. The choice of antibiotics in preventing infected necrosis during necrotizing pancreatitis should be based on their antimicrobial activity, penetration rate, persistence, and therapeutic concentrations in the necrotic pancreatic area. These requisites are provided by pefloxacin and metronidazole and to a variable extent by imipenem and mezlocillin.

Human pancreatic tissue concentration of bactericidal antibiotics

Pancreatic infection represents the most important cause of fatal outcome in human acute pancreatitis. In a comparative analysis, human pancreatic tissue concentrations of 10 different bactericidal antibiotics were determined in 89 patients undergoing pancreatic surgery. Concentrations of the antibiotics were determined in the blood and pancreatic tissue using high-pressure liquid chromatography. Pancreatic tissue concentrations 120 minutes after intravenous administration were as follows: mezlocillin, 19.0 mg/kg; piperacillin, 20.3 mg/kg; cefotaxime, 9.1 mg/kg; ceftizoxime, 7.9 mg/kg; netilmicin, 0.4 mg/kg; tobramycin, 0.4 mg/kg; ofloxacin, 1.7 mg/kg; ciprofloxacin, 0.9 mg/kg; imipenem, 6.0 mg/kg; metronidazole, 3.5 mg/kg. Three groups of antibiotics were established: group A, substances with low tissue concentrations (netilmicin, tobramycin), which were below the minimal inhibitory concentrations of most bacteria found in pancreatic infection; group B, antibiotics with pancreatic tissue concentrations which were sufficient to inhibit some but not all bacteria in pancreatic infection (mezlocillin, piperacillin, ceftizoxime, cefotaxime); group C, substances with high pancreatic tissue levels as well as high bactericidal activity against most of the germs present in pancreatic infection (ciprofloxacin, ofloxacin, imipenem). These data could serve as the basis for adequate antibiotic prophylaxis or treatment of pancreatic infection.

Extravascular penetration of ciprofloxacin. A review

The pharmacokinetics of ciprofloxacin after oral and intravenous administration have been studied extensively, and the results have been published worldwide. This paper serves as a review of the pharmacokinetics of ciprofloxacin, with specific reference to its penetration into body fluids and tissues. Ciprofloxacin has a protein binding of approximately 30% and penetrates well into tissues. For instance, the total concentration (area under the serum concentration-time curve) in peripheral human lymph is 70% of the serum values, and the peak level in lymph appears with 1-2 hr. The corresponding value for suction skin blisters is 60% and for inflammatory blisters 120%. Ciprofloxacin is concentrated in white blood cells, lung, prostate, and kidney and reaches concentrations above serum in many other tissues as well. Urine concentrations are up to 100 times those in serum. The levels in bile are comparable or only slightly higher (less than or equal to x 10) than serum levels. The penetration into cerebrospinal fluid (CSF) is low; the CSF levels are 4-10% of the serum levels in noninflammatory CSF and 30-50% in CSF from patients with meningitis.

The penetration of antibiotics into human pancreas

In order to analyse the penetration of two antibiotics (mezlocillin and metronidazole) which cover the spectrum of microorganisms involved in pancreatic infection, we determined their concentration in pancreatic tissue, juice and cyst fluid in 16 patients undergoing pancreatic surgery. In addition, the external pancreatic fistula fluid of one patient was analysed for antibiotic concentration and bacterial counts during a seven-day treatment with mezlocillin, metronidazole and netilmicin (i.v.). Antibiotic concentrations were determined by HPLC between 16 and 210 (median 74) min after i.v. administration of 4 g mezlocillin and 500 mg metronidazole, respectively. The median concentration of mezlocillin was 23.2 (range: 3.1-37.4) mg/kg, 15.9 (range: 4.2-55.0) mg/l and 9.9 (range: 5.2-14.8) mg/l in pancreatic tissue, juice and cyst fluid, respectively. The median concentration of metronidazole was 5.1 (range: 1.8-13.0) mg/kg, 8.5 (range: 3.6-16.2) mg/l and 1.2 (0.9-1.4) mg/l in pancreatic tissue, juice and cyst fluid, respectively. From the fistula patient, seven different bacteria were cultured (five aerobic and two anaerobic isolates); their concentration in fistula fluid ranged from 10(5) to 10(7) CFU/ml. The bacteria sensitive for mezlocillin and metronidazole disappeared after four days of i.v. treatment, whereas the two isolates sensitive for netilmicin showed continuous growth seven days after i.v. treatment. The peak concentrations for mezlocillin, metronidazole and netilmicin in the fistula fluid were 6.8 mg/l, 5.6 mg/l and less than 0.1 mg/l, respectively.