ESBL E coli and P. aeruginosa Resistance to Ceftolozane-Tazobactam in a Patient with a Liver Abscess. The Search for an Omnipotent Antibiotic Goes On!

Multi drug resistant (MDR) Pseudomonas aeruginosa and Extended- Spectrum-lactamase (ESBL) Enterobacteriaceae are becoming an increasing difficult clinical problem. Immediate resistance to some of the new antimicrobials such as ceftolozane/tazobactam is unusual and is due to a variety of mechanisms such as hyper-production of inactivating enzymes and gene mutation. In addition, previous antimicrobial administration is a well-recognized risk factor to develop resistance. We present a patient with a liver abscess where the organism was resistant to ceftolozane/tazobactam resulting in a poor clinical outcome.

A randomized trial of the efficacy and safety of sequential intravenous/oral moxifloxacin monotherapy versus intravenous piperacillin/tazobactam followed by oral amoxicillin/clavulanate for complicated skin and skin structure infections.

OBJECTIVES: The primary aim of the RELIEF study was to evaluate the efficacy and safety of two sequential intravenous (iv)/oral regimens: moxifloxacin iv/oral versus piperacillin/tazobactam (TZP) iv followed by oral amoxicillin/clavulanate (AMC). PATIENTS AND METHODS: The study had a prospective, randomized, double-dummy, double-blind, multicentre design. Patients ≥18 years were prospectively stratified according to complicated skin and skin structure infection (cSSSI) subtype/diagnosis (major abscess, diabetic foot infection, wound infection or infected ischaemic ulcer), surgical intervention and severity of illness. Diagnoses and disease severity were based on predetermined criteria, documented by repeated photographs, and confirmed by an independent data review committee. Patients were randomized to receive either 400 mg of moxifloxacin iv once daily followed by 400 mg of moxifloxacin orally once daily or 4.0/0.5 g of TZP iv thrice daily followed by 875/125 mg of AMC orally twice daily for 7-21 days. The primary efficacy variable was clinical response at test of cure (TOC) for the per-protocol (PP) population. Clinical efficacy was assessed by the data review committee based on repeated photographs and case descriptions. Clinical trials registry number: NCT 00402727. RESULTS: A total of 813 patients were randomized. Clinical success rates at TOC were similar for moxifloxacin and TZP-AMC in the PP [320/361 (88.6%) versus 275/307 (89.6%), respectively; P = 0.758] and intent-to-treat (ITT) [350/426 (82.2%) versus 305/377 (80.9%), respectively; P = 0.632] populations. Thus, moxifloxacin was non-inferior to TZP-AMC. Bacteriological success rates were high in both treatment arms [moxifloxacin: 432/497 (86.9%) versus TZP-AMC: 370/429 (86.2%), microbiologically valid (MBV) population]. Moxifloxacin was non-inferior to TZP-AMC at TOC in both the MBV and the ITT populations. Both treatments were well tolerated. CONCLUSIONS: Once-daily iv/oral moxifloxacin monotherapy was clinically and bacteriologically non-inferior to iv TZP thrice daily followed by oral AMC twice daily in patients with cSSSIs.

Treating diabetic foot infections with sequential intravenous to oral moxifloxacin compared with piperacillin-tazobactam/amoxicillin-clavulanate.

OBJECTIVES: Complicated skin and skin structure infections (cSSSIs), including diabetic foot infections (DFIs), are often polymicrobial, requiring combination or broad-spectrum therapy. Moxifloxacin, a broad-spectrum fluoroquinolone, is approved for cSSSI and can be administered by either intravenous (iv) or oral routes. To assess the efficacy of moxifloxacin for treating DFIs, we analysed a subset of patients with these infections who were enrolled in a prospective, double-blind study that compared the efficacy of moxifloxacin with piperacillin-tazobactam and amoxicillin-clavulanate. METHODS: Patients>or=18 years of age with a DFI requiring initial iv therapy were randomized to either moxifloxacin (400 mg/day) or piperacillin-tazobactam (3.0/0.375 g every 6 h) for at least 3 days followed by moxifloxacin (400 mg/day orally) or amoxicillin-clavulanate (800 mg every 12 h orally), if appropriate, for 7-14 days. DFI was usually defined as any foot infection plus a history of diabetes. Our primary efficacy outcome was the clinical response of the infection at test-of-cure (TOC), 10-42 days post-therapy. RESULTS: Among 617 patients enrolled in the original study, 78 with DFIs were evaluable for treatment efficacy. Clinical cure rates at TOC were similar for moxifloxacin and piperacillin-tazobactam/amoxicillin-clavulanate (68% versus 61%) for patients with investigator-defined infection (P=0.54). Overall pathogen eradication rates in the microbiologically-valid population were 69% versus 66% for moxifloxacin and comparator, respectively (P=1.00). CONCLUSIONS: Intravenous+/-oral moxifloxacin was as effective as iv piperacillin-tazobactam+/-amoxicillin-clavulanate in treating moderate-to-severe DFIs. Moxifloxacin may have potential as a monotherapy regimen for DFIs.

[Interstitial nephritis attributed to treatment with piperacillin-tazobactam and with ciprofloxacin]. / Interstitiële nefritis toegeschreven aan het gebruik van piperacilline-tazobactam en van ciprofloxacine.

A 26-year-old man was treated with piperacillin-tazobactam because of suspected cholangitis and a 77-year-old man was given ciprofloxacin because of an infected knee-prosthesis. They both developed symptoms of an interstitial nephritis: malaise and laboratory deviations. The symptoms disappeared after the antibiotics were withdrawn. No other explanation for the renal function disorders could be found in either patient. Piperacillin-tazobactam and ciprofloxacin are considered to be relatively safe and serious adverse effects are rare. Acute interstitial nephritis may, however, occur and its clinical presentation may not be very informative. Withdrawal of the culprit usually leads to recovery.

Sequential intravenous/oral moxifloxacin versus intravenous piperacillin-tazobactam followed by oral amoxicillin-clavulanate for the treatment of complicated skin and skin structure infection.

In this prospective, double-blind, multicentre trial, adult patients with complicated skin and skin structure infection (cSSSI) randomly received sequential intravenous (i.v.)/oral (p.o.) moxifloxacin (400 mg once a day) or a control regimen of i.v. piperacillin-tazobactam (3.0/0.375 g every 6 h) followed by p.o. amoxicillin-clavulanate (800 mg every 12 h), each for 7-14 days. Clinical cure rates at the test-of-cure visit (10-42 days post therapy) for the efficacy-valid population were 79% (143/180) for the moxifloxacin-treated group and 82% (153/187) for the control group (95% confidence interval, -12.04, 3.29). Bacteriological eradication rates for Staphylococcus aureus, the most prevalent organism, were 78% and 80%, respectively. The incidence of drug-related adverse events was similar for both groups (31% moxifloxacin, 30% control). Sequential i.v./p.o. moxifloxacin was as effective and well tolerated as i.v. piperacillin-tazobactam followed by p.o. amoxicillin-clavulanate in treating patients with cSSSI.

Piperacillin-tazobactam versus ciprofloxacin plus amoxicillin in the treatment of infective episodes after liver transplantation.

An optimum antimicrobial regimen for bacterial infection after orthotopic liver transplantation has not been identified. In this prospective 4 year study of patients undergoing liver transplantation, patients were randomized to receive either piperacillin-tazobactam (112 patient episodes) or ciprofloxacin plus amoxicillin (105 patient episodes) for empirical treatment of infective episodes in the first 3 months after transplant. Metronidazole was added to the ciprofloxacin-amoxicillin regimen where anaerobic infection was suspected. Patient groups were comparable with respect to clinical, biochemical and haematological parameters. At the 72 h primary efficacy end-point, the overall response rate for the intention-to-treat group was 74/112 (66.1%) for piperacillin-tazobactam and 63/105 (60.0%) for ciprofloxacin plus amoxicillin (P=0.399); the corresponding figures for the per-protocol (PP) group were 73/82 (89.0%) (piperacillin-tazobactam) and 61/80 (76.3%) (ciprofloxacin plus amoxicillin) (P=0.038). At the end-of-study assessment, 58.9% of episodes in the piperacillin-tazobactam group had a successful clinical outcome, compared with 50.5% in the ciprofloxacin plus amoxicillin group (P=0.222); the corresponding figures for the PP group were 83.5% (piperacillin-tazobactam) and 68.8% (ciprofloxacin plus amoxicillin) (P=0.038). Staphylococci and aerobic Gram-negative bacilli were the predominant pathogens in both groups. Bacteria resistant to the study drugs were encountered, including methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus faecium and multiply-resistant Klebsiella spp. Empirical monotherapy with piperacillin-tazobactam is an effective treatment for infective episodes in liver transplant patients.

Ertapenem once daily versus piperacillin-tazobactam 4 times per day for treatment of complicated skin and skin-structure infections in adults: results of a prospective, randomized, double-blind multicenter study.

We conducted a prospective, randomized, double-blind trial comparing ertapenem (1 g once daily) with piperacillin-tazobactam (3.375 g every 6 h) as parenteral treatment for 540 adults with complicated skin and skin-structure infections. The most common diagnoses were skin or soft-tissue abscesses and lower-extremity infections associated with diabetes. The mean duration (+/- standard deviation) of therapy was 9.1+/-3.1 days for ertapenem and 9.8+/-3.3 days for piperacillin-tazobactam. At the assessment of primary efficacy end point, 10-21 days after treatment, 82.4% of those who received ertapenem and 84.4% of those who received piperacillin-tazobactam were cured. The difference in response rates, adjusting for the patients' assigned strata, was -2.0% (95% confidence interval, -10.2% to 6.2%), indicating that the response rates in the 2 treatment groups were equivalent. Cure rates for the 2 treatment groups were similar when compared by stratum, diagnosis, and severity of infection. The frequency and severity of drug-related adverse events were similar in the treatment groups.

[Clinico-laboratory study of piperacillin/tazobactam in the treatment of patients with would infection]. / Kliniko-laboratornoe izuchenie piperatsillin-tazobaktama pri lechenii bol'nykh s ranevoi infektsiei.

Piperacillin/tazobactam (P/T) or tazocin was used in the treatment of 40 patients with soft tissue purulent necrotic wounds of various genesis and localization. In the majority of the patients the affection was of recurring nature. P/T was administered in a dose of 4.5 g 3 times a day for 1 to 14 days (mainly for 8 to 10 days) as 30-minute intravenous infusions. The clinical effect of the treatment was stated in 36 patients (90 per cent). In 3 out of 8 patients with diabetes mellitus the treatment failed. In 1 patient the treatment was discontinued after the first dose because of asphyxia and a short-term decrease of the arterial pressure. Among 105 microbial strains isolated from 75 patients 64 were highly susceptible to P/T, 33 were moderately susceptible and 8 were resistant. 76.3 per cent of the isolates produced beta-lactamase, 66.3 per cent of them were susceptible to P/T. 54 gram-positive and gram-negative strains were isolated from 40 patients. 16 out of the 54 strains were isolated as monocultures and the others as associations. After the treatments the pathogen eradication and the pathogen eradication followed by superinfection were stated in 26 patients (66.7 per cent). In 11 patients (28.2 per cent) the pathogen persistence was observed at the background of the clinical improvement in the majority of the patients. The relapses were recorded in 2 patients (5.1 per cent).

Piperacillin/tazobactam in comparison with clindamycin plus gentamicin in the treatment of intra-abdominal infections.

BACKGROUND: Concerned about the inactivation of piperacillin by beta-lactamase and the risk of aminoglycoside-induced nephrotoxicity and clindamycin-induced enterocolitis, we conducted the following phase III clinical trial. METHODS: Between November 1991 and March 1993, 77 surgical patients with intraabdominal infections were enrolled and randomly assigned in a 3:2 ratio to receive either piperacillin/tazobactam or clindamycin plus gentamicin to compare safety, tolerance and efficacy between both two treatment groups. RESULTS: There were 76 clinically and 50 bacteriologically evaluable patients with 80 isolated pathogens. The demographic data were comparable in both groups. There was no statistically significant difference of clinical response at any time-point of treatment, with 97.8% favorable clinical response rate in piperacillin tazobactam group and 96.6% in clindamycin plus gentamicin group at endpoint. The bacteriological eradication rates were similar, with 97.7% in piperacillin/tazobactam group and 94.4% in clindamycin plus gentamicin group at pathogen level, and 96.7% in piperacillin/tazobactam group and 95.0% in clindamycin plus gentamicin group at patient level. By susceptibility tests, only 3 (4%) isolated pathogens were resistant to piperacillin/tazobactam, which was much superior to the use of piperacillin, clindamycin or gentamicin alone in antimicrobial activity. The piperacillin tazobactam-related adverse experiences included 1 (2.1%) urticaria and 2 (4.3%) diarrhea. However, there were no significant differences in the adverse experiences between these two groups. CONCLUSIONS: This study has demonstrated that piperacillin/tazobactam is comparable with clindamycin plus gentamicin in efficacy, safety and tolerance in the treatment of surgical patients with intra-abdominal infections. The combination of piperacillin/tazobactam could potentially be the treatment of choice in adjunt to surgical management in intra-abdominal infection.

Piperacillin/tazobactam compared with ticarcillin/clavulanate in community-acquired bacterial lower respiratory tract infection.

The efficacy and safety of a new combination parenteral antibiotic, piperacillin/tazobactam, was compared with that of parenteral ticarcillin/clavulanate in the treatment of adult patients with community-acquired lower respiratory tract infections. A total of 299 patients were enrolled in this multicentre, double-blind, comparative study; 177 received piperacillin/tazobactam and 122 received ticarcillin/clavulanate. Of these, 119 met the evaluability criteria (69, piperacillin/tazobactam and 50, ticarcillin/clavulanate). The study drugs (piperacillin/tazobactam 3 g/375 mg or ticarcillin/clavulanate 3 g/100 mg) were given every 6 h by slow iv infusion for a minimum of 5 days. The favourable clinical response (cured and improved) rates of evaluable patients were 84% and 64% at endpoint (P < 0.01) for piperacillin/tazobactam and ticarcillin/clavulanate, respectively. The favourable bacteriological response at the early follow-up (eradicated and presumed eradicated) were 91% and 67% for piperacillin/tazobactam and ticarcillin/clavulanate, respectively (P < 0.01). At endpoint, 84% and 64%, respectively (P = 0.02) had a favourable response. The most common adverse experiences involved the gastrointestinal tract and occurred in 31.6% of the piperacillin/tazobactam group compared with 20.5% in the ticarcillin/clavulanate group (P = 0.02). These events were mild and generally did not affect therapy. Piperacillin/tazobactam appears to be more effective than ticarcillin/clavulanate in this patient population and is generally well tolerated.

Therapy of soft tissue infections with piperacillin/tazobactam.

The efficacy and safety of piperacillin in combination with the beta-lactamase inhibitor tazobactam were assessed in an open, multi-centre study of hospitalized patients with skin and soft tissue infections. A total of 136 patients from four countries were treated with piperacillin 4 g plus tazobactam 500 mg every 8 h. The mean duration of treatment was eight days. Clinical and bacteriological evaluations were performed one to three days and ten to 14 days post-therapy, respectively. Among 120 evaluable patients 93% were clinically cured or improved; 91% of bacteriologically evaluable patients were cured or improved. Eradication of the pathogens was observed in 85% and 95% of the evaluable patients at first and second follow-up. In 43% of the patients more than one pathogen was isolated from the wound. Persistence was commonest in patients in whom a complete surgical debridement could not be carried out. There were adverse events in 16 of the 136 patients, most commonly allergic reactions and diarrhoea. Six patients were withdrawn from the study because of side-effects.

Efficacy, safety and tolerance of parenteral piperacillin/tazobactam in the treatment of patients with lower respiratory tract infections.

An open, non-comparative multicentre study was conducted at 36 sites in six countries to test the efficacy and safety of piperacillin/tazobactam in the therapy of lower respiratory tract infections. Piperacillin 4 g and tazobactam 500 mg were administered intravenously every 8 h for a minimum of five days. Two hundred and thirty patients were enrolled: 133 were evaluable for clinical efficacy and 106 for bacteriological efficacy. The clinical response was favourable in 96% of evaluable patients and the bacterial eradication rate was 93%. Nine patients (4%) had severe adverse events related to piperacillin/tazobactam and requiring discontinuation of therapy. In this study piperacillin/tazobactam was an effective and safe drug in the treatment of hospitalized patients with lower respiratory tract infection caused by sensitive organisms.

Piperacillin-tazobactam versus imipenem-cilastatin for treatment of intra-abdominal infections.

In order to compare the clinical and microbiological efficacies and safety of piperacillin plus tazobactam with those of imipenem plus cilastatin, 134 patients with intra-abdominal infections (73 patients with appendicitis) participated in an open randomized comparative multicenter trial. A total of 40 men and 29 women (mean age, 53 years; age range, 18 to 92 years) were enrolled in the piperacillin-tazobactam group and 40 men and 25 women (mean age, 54 years; age range, 16 to 91 years) were enrolled in the imipenem-cilastatin group. The patients received either piperacillin (4 g) and tazobactam (500 mg) every 8 h or imipenem and cilastatin (500 mg each) every 8 h. Both regimens were given by intravenous infusion. A total of 113 patients were clinically evaluable. Of 55 patients who received piperacillin-tazobactam, 50 were clinically cured, while 40 of 58 patients in the imipenem-cilastatin group were clinically cured. The differences were significant (Wilcoxon test; P = 0.005). There were 4 failures or relapses in the piperacillin-tazobactam group and 18 failures or relapses in the imipenem-cilastatin group. The microorganisms isolated were eradicated in similar proportions in the two patient groups. Adverse reactions, mainly gastrointestinal disturbances and nausea, were noted in 13 patients who received piperacillin-tazobactam and in 14 patients who received imipenem-cilastatin. Results of the present study show that piperacillin-tazobactam is effective and safe for the treatment of intra-abdominal infections.

Clinical efficacy and safety of sulbactam/ampicillin in patients suffering from chronic liver disease.

Sulbactam is a new beta-lactamase inhibitor with pharmacokinetic characteristics in humans similar to those of ampicillin. A total of 41 patients hospitalized in the Clinic of Infectious Diseases, University of Naples, for chronic liver diseases, were treated with sulbactam/ampicillin (ratio 1:2) for urinary, respiratory, biliary tract or soft tissue infections. Sulbactam/ampicillin was administered im or iv at a dosage of 3-9 g/day depending on the site and severity of the infection. All the patients treated with sulbactam/ampicillin had clinical signs and symptoms of infection, and all the organisms isolated were sensitive to sulbactam/ampicillin (MIC less than 16 mg/l). For both Gram-positive and Gram-negative bacteria the sulbactam/ampicillin MICs were much lower than the ampicillin MICs. In agreement with the favourable in-vitro results, we observed good therapeutic efficacy. 85% of the patients recovered or improved within a few days of therapy, with no clinical relapses, and in 81% of the infections the responsible bacteria were completely eradicated. We observed a low number of side effects (3/41 oral candidosis; 3/41 pain at the im injection site) and no change in the blood chemistry tests.

Pharmacokinetic and therapeutic trial of sultamicillin in acute sinusitis.

Sultamicillin, an antibiotic combining ampicillin and the beta-lactamase inhibitor sulbactam, was administered to 13 patients diagnosed as having acute sinusitis. Specimens from sinus were obtained for all 13 patients by transantral puncture. Pharmacokinetics, bacteriology, and therapeutic efficacy were assessed. Eighty-five percent (11 of 13) were cured; two treatment failures were subsequently shown to have chronic (rather than acute) sinusitis during surgical exploration. Diarrhea was frequently encountered, and Clostridium difficile-associated enteritis was documented for one patient. Beta-lactamase-producing organisms were not encountered in this study; however, this study provides impetus for further controlled clinical trials.