Ofloxacin penetration into bile and pancreatic juice

Severe acute pancreatitis: eight fundamental steps revised according to the 'PANCREAS' acronym

Severe acute pancreatitis remains a life-threatening condition, responsible for many disorders of homeostasis and organ dysfunction. By means of a mnemonic 'PANCREAS', eight important steps in the management of severe acute pancreatitis are highlighted. These steps follow the principle of goal-directed therapy and should be borne in mind after diagnosis and during clinical treatment. The first step is perfusion: the goal is to reach a central venous pressure of 12-15mmHg, urinary output 0.5-1ml/kg/hour and inferior vena cava collapse index greater than 48%. Next is analgesia: multimodal, systemic and combined pharmacological agent and epidural block are possibilities. Third is nutrition: precocity, enteral feeding in gastric or post-pyloric position. Parenteral nutrition works best in difficult cases to achieve the individual total caloric value. Fourth is clinical: mild, moderate or severe pancreatitis according to the Atlanta criteria. Radiology is fifth: abdominal computed tomography on the fourth day for prognosis or to modify management. Endoscopy is sixth: endoscopic retrograde cholangiopancreatography (cholangitis, unpredicted clinical course and ascending jaundice); management of pancreatic fluid collection and 'walled-off necrosis'. Antibiotics come next: infectious complications are common causes of morbidity. The only rational indication for antibiotics is documented pancreatic infection. The last step is surgery: the dogma is represented by the 'three Ds' (delay, drain, debride). The preferred method is a minimally invasive step-up approach, which allows for gradually more invasive procedures when the previous treatment fails.

Prophylactic use of antibiotics in treatment of severe acute pancreatitis

Necrotic pancreatic infection is the most serious complication of severe acute pancreatitis (SAP). Although prophylactic antibiotics are widely used to reduce its death rate, its practical efficiency still remains controversial. Therefore, the clinical experiences with prophylactic use of antibiotics are summarized in this paper, hoping to offer certain guides to its treatment. However, results from recent studies do not support prophylactic use of antibiotics in all cases of necrotic pancreatic infection and suggest that only imipenem or meropenem can be used for no more than three weeks in patients with their pancreatic necrosis area >30% or in patients with biliogenic pancreatitis to decrease the risk of necrotic infection and its mortality rate.

Questions about the use of antibiotics in acute pancreatitis

BACKGROUND AND OBJECTIVE

The use of antibiotics in acute pancreatitis despite recent clinical trials remains controversial. The aim of this study is to review the latest clinical trials and guidelines about antibiotics in acute pancreatitis and determine its proper use.

METHODS

Through a Medline search, we selected and analyzed pertinent randomized clinical trials and guidelines that evaluated the use of antibiotics in acute pancreatitis. We answered the most frequent questions about this topic.

RESULTS AND CONCLUSION

Based on these clinical trials and guidelines, we conclude that the best treatment currently is the use of antibiotics in patients with severe acute pancreatitis with more than 30% of pancreatic necrosis. The best option for the treatment is Imipenem 3 x 500 mg/day i.v. for 14 days. Alternatively, Ciprofloxacin 2 x 400 mg/day i.v. associated with Metronidazole 3 x 500 mg for 14 days can also be considered as an option.

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.

Optimising outcomes in acute pancreatitis

Acute pancreatitis is a common cause for presentation to emergency departments. Common causes in Western societies include biliary pancreatitis and alcohol (the latter in the setting of chronic pancreatitis). Acute pancreatitis also follows endoscopic retrograde pancreatography in 5 to 10% of patients, a group that could potentially benefit from prophylactic treatment. Although episodes of pancreatitis usually run a relatively benign course, up to 20% of patients have more severe disease, and this group has significant morbidity and mortality. Therefore, attempts have been made to identify, at or soon after presentation, those patients likely to have a poor outcome and to channel resources to this group. The mainstay of treatment is aggressive support and monitoring of those patients likely to have a poor outcome. Pharmacotherapy for acute pancreatitis (both prophylactic and in the acute setting) has been generally disappointing. Efforts initially focused on protease inhibitors, of which gabexate shows some promise as a prophylactic agent. Agents that suppress pancreatic secretion have produced disappointing results in human studies. Infection of pancreatic necrosis is associated with high mortality and requires surgical intervention. In view of the seriousness of infected necrosis, the use of prophylactic antibacterials such as carbapenems and quinolones has been advocated in the setting of pancreatic necrosis. Similarly, data are accumulating to support the use of prophylactic antifungal therapy. Recently, it has become apparent that the intense inflammatory response associated with acute pancreatitis is responsible for much of the local and systemic damage. With this realisation, future efforts in pharmacotherapy are likely to focus on suppression or antagonism of pro-inflammatory cytokines and other inflammatory mediators. Similarly, animal studies have demonstrated the importance of oxidative stress in acute pancreatitis, although to date there is a paucity of information regarding the efficacy of antioxidants. Although the clinical course for most patients with acute pancreatitis is mild, severe acute pancreatitis continues to be a clinical challenge, requiring a multidisciplinary approach of physician, intensivist and surgeon.

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.

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.

Ofloxacin clinical pharmacokinetics

Ofloxacin is a new fluoroquinolone with a spectrum of activity similar to other fluoroquinolones with activity which includes Chlamydia trachomatis, Mycobacterium spp., Mycoplasma spp. and Legionella pneumophila. Through its additional mechanisms of action, ofloxacin may be less susceptible to the development of resistance from Staphylococcus aureus commonly seen with currently available fluoroquinolones. The impact of these findings cannot be evaluated without further clinical experience. The pharmacokinetics of ofloxacin are characterised by almost complete bioavailability (95 to 100%), peak serum concentrations in the range of 2 to 3 mg/L after a 400mg oral dose and an average half-life of 5 to 8h. In comparison with other available quinolones, elimination is more highly dependent on renal clearance, which may lead to more frequent dosage adjustments in patients with impaired renal function. Ofloxacin appears less likely to affect the pharmacokinetics of drugs (e.g. theophylline) which commonly interact with fluoroquinolones such as ciprofloxacin and enoxacin. The properties of ofloxacin make it a therapeutic alternative to currently available fluoroquinolones.

High-pressure liquid chromatography and microbiological assay of serum ofloxacin levels in adults receiving intravenous and oral therapy for skin infections

Thirty-two adults hospitalized with skin and skin structure infections received intravenous ofloxacin followed by oral ofloxacin. The standard treatment was 400 mg every 12 h. One patient with renal failure received 400 mg every 24 h. Serum ofloxacin levels were measured (1.5 h postdose and 1 h predose) during intravenous (32 patients) and oral (30 patients) therapy. Levels were assayed by high-pressure liquid chromatography (HPLC) and microbiological assay (MBA). Mean levels +/- standard deviation (in micrograms per milliliter) when measured by MBA after intravenous dosing were (postdose versus predose) 6.23 +/- 2.49 versus 2.42 +/- 1.56, and those after oral dosing were 6.17 +/- 3.25 versus 3.49 +/- 2.77. When measured by HPLC, mean levels +/- standard deviation after intravenous dosing were 5.81 +/- 2.08 versus 2.14 +/- 1.26 and those after oral dosing were 5.63 +/- 2.92 versus 3.41 +/- 2.98. There were no significant differences between levels achieved with oral or intravenous dosing when measured by either MBA or HPLC. Levels in serum did not correlate with side effects. The MICs for 50 and 90% of the 40 aerobic pathogens isolated from 21 patients were 0.5 and 2.0 micrograms/ml, respectively. Cure or improvement was achieved in 30 patients. Intravenous and oral administration of ofloxacin yielded similar levels in serum which were safe and effective in the therapy of skin infections in adult patients.

Ofloxacin. A reappraisal of its antimicrobial activity, pharmacology and therapeutic use

Ofloxacin is a fluoroquinolone whose primary mechanism of action is inhibition of bacterial DNA gyrase. In vitro it has a broad spectrum of activity against aerobic Gram-negative and Gram-positive bacteria, although it is poorly active against anaerobes. Ofloxacin, unlike most other broad spectrum antibacterial drugs, can be administered orally as well as intravenously. Penetration into body tissues and fluids is highly efficient. Clinical trials with orally and intravenously administered ofloxacin have confirmed its potential for use in a wide range of infections, where it has generally proved as effective as standard treatments. Ofloxacin in well tolerated, and in comparison with other available fluoroquinolones is less likely to cause clinically relevant drug interactions. Ofloxacin thus offers a valuable oral treatment (with an option for intravenous administration if necessary) for use in a wide range of clinical infections, but with a particular advantage in more severe or chronic infections when recourse to parenteral broad spectrum agents would normally be required, thereby providing cost savings and additionally allowing outpatient treatment.