Composite particle formulations of colistin and meropenem with improved in-vitro bacterial killing and aerosolization for inhalation

Antibiotic combination therapy is promising for the treatment of lower respiratory tract infections caused by multi-drug resistant Gram-negative pathogens. Inhaled antibiotic therapy offers the advantage of direct delivery of the drugs to the site of infection, as compared to the parenteral administrations. In this study, we developed composite particle formulations of colistin and meropenem. The formulations were characterized for particle size, morphology, specific surface area, surface chemical composition, in-vitro aerosolization performance and in-vitro antibacterial activity. The combinations demonstrated enhanced antibacterial activity against clinical isolates of Acinetobacter baumannii N16870 and Pseudomonas aeruginosa 19147, when compared with antibiotic monotherapy. Spray-dried meropenem alone showed a poor aerosolization performance as indicated by a low fine particle fraction (FPF) of 32.5 ± 3.3%. Co-spraying with colistin improved the aerosolization of meropenem with up to a two-fold increase in the FPF. Such improvements in aerosolization can be attributed to the enrichment of colistin on the surface of composite particles as indicated by X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS), and the increases in particle porosity. Intermolecular interactions between colistin and meropenem were observed for the combination formulations as measured by FT-IR. In conclusion, our results show that co-spray drying with colistin improves the antibacterial activity and aerosol performance of meropenem and produces a formulation with synergistic bacterial killing.

Conservative management of acute calculous cholecystitis complicated by pancreatitis in an elderly woman: A case report

RATIONALE

Acute calculous cholecystitis is a prevalent disease whose diagnosis and management still face significant debate. Although the overall incidence of gallstone disease is 18.8% in European women aged 30 to 69 years, there is little data and experience in managing acute calculous cholecystitis in populations over 80 years old. The incidence of acute cholecystitis among the elderly is probably increasing. For the reason, we here highlight the advantages and disadvantage of various treatment and management opens based on a 96-year-old patient.

PATIENT CONCERNS

We present a rare case in which a 96-year-old woman suffered from abdominal pain, nausea, and lack of appetite for over a month.

DIAGNOSES

She was diagnosed with acute calculous cholecystitis and pancreatitis.

INTERVENTIONS

She was successfully treated without surgery, regaining her physical health after 5 months.

OUTCOMES

The question of how to manage acute calculous cholecystitis is extremely difficult in many aspects. The patient of very advanced age presented in this paper, not very well diagnosed and with a life-threating condition, survived because of careful treatment and reasonable decision-making.

LESSONS

The take-away from this case is that, in a high-risk senile patient, strict conservative therapy of cholecystitis may be successful, as it can avoid the complications of surgery and leave the patient with a good quality of life.

A successful treatment of necrotizing fasciitis following the surgery of distal radius plate removal: A case report and literature review

RATIONALE

Necrotizing fasciitis (NF) is defined as a rare, rapidly progressive, and highly lethal skin infection characterized by necrosis of the fascia and subcutaneous tissue.

PATIENT CONCERNS

The present study aims to discuss the case of a 35-year-old man who developed NF following a routine sterile right distal radius bone plate removal surgery.

DIAGNOSES

The patient was suspected of NF based on his clinical manifestations, laboratory tests, and imaging results. The diagnosis of NF was confirmed by histological examinations.

INTERVENTIONS

Serial prompt and extensive debridement was performed during the rapid and aggressive extension of the skin infection, together with antibiotics and supportive treatments.

OUTCOMES

The condition of the patient finally improved on the sixth day of disease progression. Skin grafting of his right forearm wound was performed successfully 2 months after the admission.

LESSONS

NF can occur during the perioperative period for routine clean radius plate removal operation in patients with no risk factor for NF. The objective is to remind the physicians to stay aware of this disease, especially its early clinical signs and symptoms. Urgent subsequent treatment, including surgical debridement, antibiotic therapy, and supporting management, is the key to ensure the survival and better prognosis of patients.

Effect of Meropenem-Vaborbactam vs Piperacillin-Tazobactam on Clinical Cure or Improvement and Microbial Eradication in Complicated Urinary Tract Infection: The TANGO I Randomized Clinical Trial

IMPORTANCE

Meropenem-vaborbactam is a combination carbapenem/beta-lactamase inhibitor and a potential treatment for severe drug-resistant gram-negative infections.

OBJECTIVE

To evaluate efficacy and adverse events of meropenem-vaborbactam in complicated urinary tract infection (UTI), including acute pyelonephritis.

DESIGN, SETTING, AND PARTICIPANTS

Phase 3, multicenter, multinational, randomized clinical trial (TANGO I) conducted November 2014 to April 2016 and enrolling patients (≥18 years) with complicated UTI, stratified by infection type and geographic region.

INTERVENTIONS

Eligible patients were randomized 1:1 to receive meropenem-vaborbactam (2g/2g over 3 hours; n = 274) or piperacillin-tazobactam (4g/0.5g over 30 minutes; n = 276) every 8 hours. After 15 or more doses, patients could be switched to oral levofloxacin if they met prespecified criteria for improvement, to complete 10 days of total treatment.

MAIN OUTCOMES AND MEASURES

Primary end point for FDA criteria was overall success (clinical cure or improvement and microbial eradication composite) at end of intravenous treatment in the microbiologic modified intent-to-treat (ITT) population. Primary end point for European Medicines Agency (EMA) criteria was microbial eradication at test-of-cure visit in the microbiologic modified ITT and microbiologic evaluable populations. Prespecified noninferiority margin was -15%. Because the protocol prespecified superiority testing in the event of noninferiority, 2-sided 95% CIs were calculated.

RESULTS

Among 550 patients randomized, 545 received study drug (mean age, 52.8 years; 361 [66.2%] women; 374 [68.6%] in the microbiologic modified ITT population; 347 [63.7%] in the microbiologic evaluable population; 508 [93.2%] completed the trial). For the FDA primary end point, overall success occurred in 189 of 192 (98.4%) with meropenem-vaborbactam vs 171 of 182 (94.0%) with piperacillin-tazobactam (difference, 4.5% [95% CI, 0.7% to 9.1%]; P < .001 for noninferiority). For the EMA primary end point, microbial eradication in the microbiologic modified ITT population occurred in 128 of 192 (66.7%) with meropenem-vaborbactam vs 105 of 182 (57.7%) with piperacillin-tazobactam (difference, 9.0% [95% CI, -0.9% to 18.7%]; P < .001 for noninferiority); microbial eradication in the microbiologic evaluable population occurred in 118 of 178 (66.3%) vs 102 of 169 (60.4%) (difference, 5.9% [95% CI, -4.2% to 16.0%]; P < .001 for noninferiority). Adverse events were reported in 106 of 272 (39.0%) with meropenem-vaborbactam vs 97 of 273 (35.5%) with piperacillin-tazobactam.

CONCLUSIONS AND RELEVANCE

Among patients with complicated UTI, including acute pyelonephritis and growth of a baseline pathogen, meropenem-vaborbactam vs piperacillin-tazobactam resulted in a composite outcome of complete resolution or improvement of symptoms along with microbial eradication that met the noninferiority criterion. Further research is needed to understand the spectrum of patients in whom meropenem-vaborbactam offers a clinical advantage.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT02166476.

Emphysematous endocarditis caused by AmpC beta-lactamase-producing Escherichia coli: A case report

RATIONALE

Infective endocarditis (IE) is a life-threatening disease, mostly caused by gram-positive bacteria. Gram-negative bacteria were identified as a causative organism in relatively small number of cases. Although, antibiotic-resistant Escherichia coli is common cause of gram-negative endocarditis, AmpC beta-lactamase (BL)-harboring E coli is very rare cause of IE. Furthermore, emphysematous endocarditis is also a very rare manifestation of E coli infection.

PATIENT CONCERNS

We report a case of 80-year-old female patient presenting with dizziness, fever, and altered mental status, who was finally diagnosed with emphysematous endocarditis caused by E coli harboring an AmpC BL gene.

DIAGNOSIS

Her chest computed tomography revealed air bubbles surrounding the annulus of a mitral valve and a transesophageal echocardiogram revealed a hyperechogenic mass fixed on the posteromedial side of the mitral annulus with 2 eccentric mitral regurgitation jets. Blood cultures grew E coli which harbored the DHA-type AmpC BL. The organism belonged to a B2 phylogenic group, and multilocus sequence typing analyses revealed that the strains were of ST-95.

INTERVENTIONS

She was treated with meropenem following the resistant profiles, and surgery was recommended by the healthcare professional, but denied by the patient's guardians. She was transferred to another hospital due to a refusal for further treatment.

LESSONS

Emphysematous endocarditis is an uncommon complication of E coli bacteremia. Certain phylogenetic groups may be associated with development of E coli endocarditis.

Pharmacokinetics of high-dose extended-infusion meropenem during pulmonary exacerbation in adult cystic fibrosis patients: a case series

This case series explored the pharmacokinetic/pharmacodynamic (PK/PD) characteristics of meropenem (MEM) in adult cystic fibrosis (CF) patients hospitalized for a pulmonary exacerbation. From January 2015 to June 2016, all adult patients with cystic fibrosis (CF) and chronic pulmonary infection due to meropenem (MEM)-susceptible/intermediate Pseudomonas aeruginosa who received at least 48 h of MEM as an extended 3-hour infusion for treating a pulmonary exacerbation were enrolled. MEM plasma concentrations were determined by high-performance liquid chromatography. Six adult CF patients with a median age of 47 years were included in the study. MEM showed a high Vd (mean 45.98 L, standard deviation [SD] ±34.45). A minimal PK/PD target of 40% T > minimum inhibitory concentration (MIC) with respect to the MEM MIC of P. aeruginosa strains isolated from sputum during exacerbation was achieved in 5/6 patients (83%). MEM failed to achieve this target only in one patient, whose strain showed the highest MEM MIC in our cohort (8 mg/L). In all patients, MEM was well tolerated, and no adverse events were reported. In conclusion, high-dose, extended-infusion MEM during pulmonary exacerbation showed a high Vd in six adult CF patients with high median age, and was well tolerated.

Dosing antibiotics in neonates: review of the pharmacokinetic data

Antibiotics are often used in neonates despite the absence of relevant dosing information in drug labels. For neonatal dosing, clinicians must extrapolate data from studies for adults and older children, who have strikingly different physiologies. As a result, dosing extrapolation can lead to increased toxicity or efficacy failures in neonates. Driven by these differences and recent legislation mandating the study of drugs in children and neonates, an increasing number of pharmacokinetic studies of antibiotics are being performed in neonates. These studies have led to new dosing recommendations with particular consideration for neonate body size and maturation. Herein, we highlight the available pharmacokinetic data for commonly used systemic antibiotics in neonates.

Meropenem for treating KPC-producing Klebsiella pneumoniae bloodstream infections: Should we get to the PK/PD root of the paradox?

The objective of this study was to assess the achievement of pharmacokinetic/pharmacodynamic (PK/PD) targets of meropenem (MEM) in critically-ill patients with bloodstream infections (BSI) due to Klebsiella pneumoniae-carbapenemase-producing Klebsiella pneumoniae (KPC-Kp) with MEM minimum inhibitory concentrations (MICs) ≥16 mg/L. Nineteen critically-ill patients with KPC-Kp BSI were given combination therapy including MEM, tigecycline, plus colistin or gentamicin (according to susceptibility testing). MEM was administered as an extended 3-hour infusion of 2 g every 8 hours, or adjusted according to renal function. MEM plasma concentrations were determined by high-performance liquid chromatography. PK/PD targets for MEM were defined as T > 40% 1×MIC and T > 40% 4×MIC. Possible synergisms between MEM and coadministered agents were assessed by time-kill assays based on plasma levels for MEM and on fixed plasma concentrations for the other agents. In none of 19 patients MEM reached any PK/PD target. The actual MEM MICs were 256, 512, and 1024 mg/L in 1, 3, and 15 isolates, respectively. However, theoretically, the PK/PD target of T > 40% 1×MIC could have been achieved in 95%, 68%, 32% and 0% of the isolates for MIC equal to 8, 16, 32, and 64 mg/L, respectively. No synergisms were observed between MEM and coadministered agents. In conclusion, high-dose MEM failed to reach PK/PD targets in 19 patients with BSI due to KPC-Kp with very high MEM MICs. On a theoretical basis, our results suggest a possible usefulness of MEM against resistant blood isolates with MICs up to 32 mg/L.

Meropenem by Continuous Versus Intermittent Infusion in Ventilator-Associated Pneumonia due to Gram-Negative Bacilli

Background:

It is known that β-lactam antibiotics exhibit time-dependent bactericidal activity. Several studies have found continuous infusion of meropenem more effective than intermittent infusion in maintaining constant serum concentrations in excess of the minimum inhibitory concentration. However, limited data exist on the clinical efficacy of meropenem administered by continuous infusion.

Objective:

To evaluate the clinical efficacy of continuous versus intermittent infusion of meropenem for the treatment of ventilator-associated pneumonia (VAP) due to gram-negative bacilli.

Methods:

A retrospective cohort study was conducted of patients with VAP caused by gram-negative bacilli who received initial empiric antibiotic therapy with meropenem. We analyzed 2 contemporary cohorts: one group received meropenem by continuous infusion (1 g over 360 min every 6 h), the other by intermittent infusion (1 g over 30 min every 6 h). The administration method was prescribed according to the physician's discretion. Patients received meropenem plus tobramycin for 14 days.

Results:

There were no significant differences between patient groups with regard to gender, age, APACHE-II at intensive care unit admission, diagnosis, microorganism responsible for VAP, or organ dysfunction severity at the time VAP was suspected. The group receiving medication by continuous infusion showed a greater clinical cure rate than the group treated with intermittent infusion (38 of 42, 90.47%, vs 28 of 47, 59.57%, respectively, with OR 6.44 [95% Cl 1.97 to 21.05; p < 0.001]).

Conclusions:

Meropenem administered by continuous infusion may have more clinical efficacy than intermittent infusion.

Purple Urine Bag Syndrome

Purple Urine Bag Syndrome (PUBS) refers to the purple discoloration of urine and is commonly observed in bed ridden patients with long-term urinary catheters. Although typically benign, the purple discoloration is alarming to both the patients and their attendants. This case report presents an uncommon case of PUBS in a 60-year-old lady with hypertension, type II diabetes, and chronic kidney disease stage 5, who presented to the emergency room with bilateral diabetic foot ulcers of 3 months duration, dry gangrene of ring finger and infected middle and little fingers with abscess over the palmar aspect of right hand of 20 days duration. PUBS is generally associated with alkaline urine as was observed in this patient, although it has also been reported in acidic urine. PUBS has long been documented in association with constipation and so has its association with diarrhea, a finding also observed in this case report.

A young infant with transient severe hypertriglyceridemia temporarily associated with meropenem administration: A case report and review of the literature

BACKGROUND

Slight changes in the lipid profile can be observed over the acute phase of infectious diseases. Moreover, some anti-infective drugs can modify serum lipid concentrations, although antibiotics do not seem to have a relevant, direct, or acute effect on the lipid profile.

METHODS

A 75-day-old breastfed Caucasian female, born at term after a regular pregnancy, was hospitalized for osteomyelitis. She was immediately treated with intravenous meropenem and vancomycin. Therapy was effective, but after 22 days of treatment, her blood was found to be viscous with a purple shade.

RESULTS

A fasting blood sample showed serum triglycerides of 966 mg/dL, total cholesterol of 258 mg/dL, and high-density lipoprotein cholesterol of 15 mg/dL. Secondary causes of hyperlipidemia and primary hereditary disorders were ruled out. Thereafter, the possibility that antibiotics may have had a role in the hypertriglyceridemia was considered, and meropenem was discontinued. After 72 hours of meropenem discontinuation, a sharp modification of lipid variables was observed, and further testing showed a complete normalization of the lipid profile.

CONCLUSION

In this child with osteomyelitis, the increase in serum triglycerides appeared suddenly after 3 weeks of meropenem treatment and resolved quickly after meropenem discontinuation, thus highlighting the possible association between meropenem and lipid profile alterations. Monitoring the lipid profile should be considered in cases of long-term treatment with meropenem, and further studies on meropenem safety should include evaluation of the lipid profile.

Is high-dose β-lactam therapy associated with excessive drug toxicity in critically ill patients?

BACKGROUND

β-lactam antibiotics may necessitate higher than licensed drug doses to achieve therapeutic exposures in critically ill patients. Therapeutic drug monitoring can be used to guide dosing so as to maximise therapeutic effect whilst reducing the likelihood of exposure-related toxicity.

METHODS

A retrospective review of critically ill patients identified those that received higher than licensed doses of either meropenem (3-6 g/day) or piperacillin-tazobactam (16 g-2 g/day) (i.e. high-dose group) guided by therapeutic drug monitoring. β-lactam-associated toxicities were compared with a patient group of similar age, sex, body mass index and admission diagnosis that received licensed doses of either antibiotic.

RESULTS

Mean daily doses were more than 40% higher in the high-dose groups for each antibiotic. There were no significant differences between the high-dose and licensed-dose groups in terms of hepatocellular derangement (17.9% vs. 31.8%, P=0.25 for meropenem and 17.4% vs. 16.0%, P=0.90 for piperacillin-tazobactam), cholestasis (28.0% vs. 13.6%, P=0.32 for meropenem and 13.0% vs. 4.0%, P=0.26 for piperacillin-tazobactam), need for continuous renal replacement therapy (0% vs. 9.1%, P=0.10 for meropenem and 0% vs. 8.0%, P=0.16 for piperacillin-tazobactam), seizure incidence (7.1% vs. 4.5%, P=0.70 for meropenem and nil for either piperacillin-tazobactam group), thrombocytopenia (9.1% vs. 10.7%, P=0.85 for meropenem and 4.0% vs. 4.3% for piperacillin-tazobactam), or neutropenia (4.5% vs. 3.6%, P=0.95 for meropenem and 0.0% vs. 4.3% for piperacillin-tazobactam).

CONCLUSIONS

Higher than licensed doses of meropenem and piperacillin-tazobactam guided by therapeutic drug monitoring were not associated with additional toxicities. Larger prospective studies are required to confirm the clinical utility of higher than licensed dosing.

A single dose of meropenem is superior to ciprofloxacin in preventing infections after transrectal ultrasound-guided prostate biopsies in the era of quinolone resistance

PURPOSE

To evaluate the efficacy of meropenem single dose before transrectal prostate biopsy, instead of ciprofloxacin in the era of fluoroquinolones resistance.

METHODS

This prospective study included patients with indications for prostatic biopsy from January to December 2014. Those with known resistance in fluoroquinolones or meropenem or with decreased creatinine clearance were excluded. Patients were randomized into two groups, and statistical analysis was carried out. Group A received a 3-day course of ciprofloxacin 500 bid per os starting the day before biopsy. Group B received 1 g meropenem intravenously 1 h prior to the procedure. Patients were followed up for 15 days, and those with lower urinary tract symptoms (LUTS) and fever were called for hospitalization. Urine and blood cultures were obtained.

RESULTS

A total of 110 patients, 52-75 years old (mean 67.5, median 66) participated in the study, allocated in Groups A and B. After the procedure, 18 patients (32.7 %) of Group A reported macroscopic hematuria, while 10 (18.2 %) reported rectal blood loss. Nine patients (16.3 %) presented because of fever and LUTS. One of them developed septic shock and died in the ICU. Cultures revealed multi-resistant E. coli with high sensitivity to meropenem, and patients were treated accordingly. In Group B, 20 (36.3 %) patients presented with macroscopic hematuria and 9 (16.3 %) with rectal blood loss. One patient returned to hospital with LUTS and fever. Cultures revealed Klebsiella pneumoniae sensitive to colimycine.

CONCLUSIONS

A single dose of meropenem prior to prostate biopsy is a safe and effective way to avoid the possible infectious complications in high-risk patients.

[Results of a post-marketing surveillance of meropenem administered over 2 g/day for serious infectious diseases]

The post-marketing surveillance of meropenem (Meropen®) administered over 2g/day for serious infectious diseases was conducted between August 2011 and June 2013 to evaluate safety and efficacy under actual clinical use. There were 382 and 322 evaluable cases for safety and efficacy respectively, of 399 case cards collected from 87 institutions. In safety analysis, the incidence of adverse drug reactions (ADRs) associated with use of meropenem (including abnormal laboratory findings) was 19.1% (73/382 cases), and the main ADRs were hepatic function abnormal, aspartate aminotransferase increased, alanine aminotransferase increased, liver disorder, and diarrhoea, which were similar to these observed in the post-marketing surveillances of meropenem conducted before. In efficacy analysis, the efficacy was 73.6% (237/322 cases), which is as same as 71.4% (3214/4504 cases) of post-marketing surveillance of meropenem conducted after first approval under 2 g/day for infectious diseases. These results confirmed meropenem (Meropen®) is one of the useful antimicrobial agents for serious infectious diseases.

Central skull base osteomyelitis: a rare but life-threatening disease

We present the case of a 70-year-old non-diabetic patient who presented to the emergency department with unrelenting otalgia. A severe otitis externa (OE) and mastoiditis were treated with broad spectrum antibiotics and surgical drainage. No bacteria was isolated from surgical samples. Because the otalgia persisted, a magnetic resonance (MR) was performed and showed an infiltrating process at the skull base. Biopsies failed to prove malignancy or granulomatosis. The patient's neurological state deteriorated. The suspicion of a skull base osteomyelitis (SBO) was raised and proven by CT-guided biopsies that grew Pseudomonas aeruginosa. Meropenem and ciprofloxacin, given for 8 weeks, lead to a fast clinical improvement and a full recovery. SBO is uncommon, often complicating severe OE. Pseudomonas aeruginosa is the main pathogen. Prompt diagnosis and adequate antibiotherapy are required to lower mortality and morbidity. The diagnosis may be delayed because of unawareness and large differential diagnosis including solid neoplasic tumours, malignant hemopathies and granulomatosis.

Cefozopran, meropenem, or imipenem-cilastatin compared with cefepime as empirical therapy in febrile neutropenic adult patients: A multicenter prospective randomized trial

We conducted an open-label, randomized study to evaluate the clinical efficacy of cefozopran, meropenem or imipenem-cilastatin using cefepime as a control in febrile neutropenia (FN) patients. Three hundred and seventy-six patients received cefepime, cefozopran, meropenem or imipenem-cilastatinas initial therapy for FN. The primary endpoint was the non-inferiority of response rates including modification at day 7 in cefozopran, meropenem or imipenem-cilastatin patients compared with cefepime in the per-protocol population (delta = 10%). The response rates for cefozopran, meropenem and imipenem-cilastatin were not significantly different compared with cefepime (cefozopran: 54/90 (60%), meropenem: 60/92 (65%), and IPM/CS: 63/88 (72%) versus cefepime: 56/85 (66%) (p = 0.44, 1.0 and 0.51, respectively)), and the differences in treatment success for cefozopran, meropenem and imipenem-cilastatin compared with cefepime were -5.9% (95% confidence interval (CI): -20.1-8.4), -0.7% (95% CI: -14.6-13.3), and 5.7% (95% CI: -8.1-19.4), respectively. The same tendency was seen in the modified intention-to-treat population. Based on the evaluation of initial drug efficacy performed on days 3-5, there was no significant difference between the four drugs. In the subgroup with an absolute neutrophil count ≤ 100 × 10(6)/L for longer than seven days, there was significantly better efficacy in the carbapenem arm compared to 4th generation beta-lactams (52% versus 27% at days 3-5, p = 0.006, and 76% versus 48% at day 7, p = 0.002). Our results suggest that the effects of these four drugs as empiric therapy were virtually the same for adult FN patients, although non-inferiority was shown only in imipenem-cilastatin compared with cefepime (clinical trial number: UMIN000000462).

Lemierre's Syndrome Associated with Periodontal Injury-derived Odontogenic Infection that Did Not Respond to Meropenem

A 33-year-old previously healthy man injured his gums and subsequently developed dyspnea and fever. A chest X-ray showed nodules and infiltrates in both lungs, and the patient was initially diagnosed with pneumonia and administered meropenem hydrate, although his symptoms did not improve. A blood culture identified Fusobacterium necrophorum, and thrombophlebitis in the internal jugular vein of the neck was observed on computed tomography and ultrasound scans. We replaced the meropenem with clindamycin, sulbactam/ampicillin and metronidazole, and the patient's symptoms improved.

Severe Sepsis due to Otogenic Pneumococcal Meningitis with Pneumocephalus without Meningeal Symptoms

The absence of meningeal signs and symptoms is rare in patients with bacterial meningitis and may lead to a delay in diagnosis and treatment. Furthermore, the onset of bacterial meningitis associated with pneumocephalus is a rare complication of ear infections. We herein report a rare case of otogenic meningitis complicated by pneumocephalus that was initially missed due to the absence of typical meningeal signs and symptoms and later diagnosed correctly based on a thorough review of the patient's systems.

Sphenoid Sinusitis Complicated by Pneumococcal Meningitis and an Infectious Aneurysm in the Intracavernous Carotid Artery

A 61-year-old Japanese woman presented with a headache and appetite loss lasting for nine days and was admitted to our hospital, where she was diagnosed with pneumococcal meningitis associated with acute sphenoid sinusitis. While the administration of meropenem and dexamethasone ameliorated the meningitis, right third and sixth nerve palsy suddenly developed 10 days after admission. CT angiography subsequently demonstrated an aneurysm in the cavernous portion of the right internal carotid artery. This is the first reported case of sphenoid sinusitis simultaneously complicated by both pneumococcal meningitis and an infectious aneurysm in the intracavernous carotid artery.

Successful Treatment of Early-Diagnosed Primary Phlegmonous Gastritis

A 64-year-old man presented with epigastralgia and nausea after an acute exacerbation of chronic pancreatitis. Abdominal computed tomography revealed remarkable thickening of the gastric wall and intramural hypodense areas. Esophagogastroduodenoscopy showed a large gastric ulcer surrounded by an edematous mucosa and mucopus. The results of a culture from a biopsy of the lesion indicated phlegmonous gastritis. The patient was successfully treated with an antibiotic without gastrectomy.

Extended versus bolus infusion of meropenem and piperacillin: a pharmacokinetic analysis

BACKGROUND

Extended infusion of beta-lactam antibiotics has been advocated as a method for optimizing antibiotic exposure in critically ill patients. The objective of this study was to compare the pharmacokinetics/pharmacodynamics of extended infusion versus bolus infusion of piperacillin and meropenem in critically ill patients with normal renal function.

METHODS

A prospective study of 3 hours extended infusion of meropenem and piperacillin in critically ill patients without renal dysfunction. Results from the extended infusion cohort were compared to previously published bolus infusion data in critically ill patients.

RESULTS

Twenty extended infusion patients (15 piperacillin, 5 meropenem) were compared with 13 bolus infusion patients (8 piperacillin, 5 meropenem). The demographic and clinical characteristics between both groups were not statistically different. Significant pharmacokinetic differences were observed in median (interquartile range) Cmax for both meropenem (extended infusion 17 [12.6-21.9] vs. bolus 85.2 [66.7-140.3]; P=0.01) and piperacillin (extended infusion 76.2 [57.7-92.6] vs. bolus 240.2 [168.5-275.4]; P=0.001). Considerable pharmacokinetic variability existed in each group for both drugs. Compared to bolus infusion, fT>MIC using extended infusion was higher for both drugs: 96% (IQR 71-100%) compared to 77% (IQR 41-93%) for piperacillin (P=0.05) and 82% (IQR 63-89%) compared to 51% (IQR 48-63%) for meropenem (P=0.095); assuming a MIC of 16 mg/L and 2 mg/L respectively.

CONCLUSION

This study confirms that extended infusion in critically ill patients result in advantageous pharmacokinetic profiles by increasing the fT>MIC for piperacillin and meropenem. In a significant subpopulation of critically ill patients with normal renal function, a 100% fT>MIC target is not reached, even with 3-hour extended infusions.

Multicenter, double-blind, randomized, phase II trial to assess the safety and efficacy of ceftolozane-tazobactam plus metronidazole compared with meropenem in adult patients with complicated intra-abdominal infections

Ceftolozane-tazobactam (TOL-TAZ) is a novel antibacterial with activity against Pseudomonas aeruginosa and other common Gram-negative pathogens, including extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae, that are associated with complicated intra-abdominal infections (cIAIs). This prospective, double-blind, randomized, multicenter, phase II trial assessed patient clinical and microbiological responses to and the safety of TOL-TAZ plus metronidazole compared with those of meropenem. Hospitalized adults with cIAIs that required surgical intervention were randomized (2:1) to receive intravenous (i.v.) TOL-TAZ (1.5 g [containing 1,000 mg TOL and 500 mg TAZ] every 8 h [q8h]) with or without i.v. metronidazole (500 mg q8h) or i.v. meropenem (1 g q8h) for 4 to 7 days. The primary endpoint was the clinical response at the test-of-cure visit in the microbiologically modified intent-to-treat (mMITT) and microbiologically evaluable (ME) populations. Secondary measures included the patients' microbiological response and safety. In total, 82 patients received TOL-TAZ (90.2% with metronidazole), and 39 received meropenem. For the mMITT population, clinical cure was seen in 83.6% of the patients (51/61; 95% confidence interval [CI], 71.9 to 91.8) who received TOL-TAZ and 96.0% of the patients (24/25; 95% CI, 79.6 to 99.9) who received meropenem (difference, -12.4%; 95% CI, -34.9% to 11.1%); in the ME population, clinical cure was seen in 88.7% and 95.8% of the patients (difference, -7.1%; 95% CI, -30.7% to 16.9%) who received TOL-TAZ and meropenem, respectively. TOL-TAZ demonstrated microbiological success against Escherichia coli (89.5%), Klebsiella pneumoniae (100%), and P. aeruginosa (100%). The adverse event rates were similar in the groups (50.0% with TOL-TAZ and 48.8% with meropenem). TOL-TAZ in combination with metronidazole was well tolerated and resulted in clinical and microbiological success rates supportive of further clinical development in patients with cIAIs. (This study has been registered at ClinicalTrials.gov under registration no. NCT01147640.).

Pharmacokinetics of short versus extended infusion meropenem dosing in critically ill patients: a pilot study

OBJECTIVE

To test whether a prolonged 3-hour infusion of meropenem 500mg achieves an equivalent proportion of time above the minimal inhibitory concentration (MIC) (%TMIC) to that of meropenem 1000mg given over 30 minutes.

DESIGN, SETTING AND PARTICIPANTS

A randomised crossover study in 10 critically ill patients.

METHOD

We administered meropenem as a 1000mg, 30-minute infusion or as a 500mg, 3-hour infusion. We determined serial plasma concentrations for each dosing episode and performed comparisons of %TMIC at different MICs.

OUTCOME MEASURES

The percentage of time that meropenem was above its MIC.

RESULTS

For low MICs (≤2 mg/L), both regimens attained a %TMIC >40% in all patients. For an MIC of 4mg/L, this target was attained in all but one patient, but with an MIC of 8mg/L, three patients in each group had a %TMIC <40%. There was no difference in target attainment between the two regimens for MICs up to 8mg/L. There was marked variability in the pharmacokinetic and hence the pharmacokinetic-pharmacodynamic parameters between individuals. Several patients had elevated creatinine clearances and, with both regimens, their target attainment was poor.

CONCLUSIONS

Meropenem at 1000mg over 30 minutes achieved a similar %TMIC to meropenem at 500mg given over 3 hours. Meropenem pharmacokinetics were highly variable from individual to individual.

Continuous infusions of meropenem in ambulatory care: clinical efficacy, safety and stability

OBJECTIVES

Concerns regarding the clinical impact of meropenem instability in continuous infusion (CI) devices may contribute to inconsistent uptake of this method of administration across outpatient parenteral antimicrobial therapy (OPAT) services.

METHODS

We retrospectively reviewed the clinical efficacy and safety of CIs of meropenem in two Australian tertiary hospitals and assessed its stability under simulated OPAT conditions including in elastomeric infusion devices containing 1% (2.4 g) or 2% (4.8 g) concentrations at either 'room temperature' or 'cooled' conditions. Infusate aliquots were assayed at different time-points over 24 hours.

RESULTS

Forty-one (82%) of 50 patients had clinical improvement or were cured. Adverse patient outcomes including hemato-, hepato- and nephrotoxicity were infrequent. Cooled infusers with 1% meropenem had a mean 24-hour recovery of 90.3%. Recoveries of 1% and 2% meropenem at room temperature and 2% under cooled conditions were 88%, 83% and 87%, respectively. Patients receiving 1% meropenem are likely to receive >95% of the maximum deliverable dose (MDD) over a 24-hour period whilst patients receiving 2% meropenem should receive 93% and 87% of the MDD under cooled and room temperature conditions, respectively.

CONCLUSIONS

Meropenem infusers are likely to deliver ∼95% MDD and maintain effective plasma concentrations throughout the dosing period. These data reflect our local favourable clinical experience with meropenem CIs.

[Case of sever septic shock following transurethral lithotripsy]

A 62-year-old man was scheduled for transurethral lithotripsy. Systemic shivering, vomiting and decreased blood pressure occurred after extubation. Blood gas analysis showed metabolic acidosis. After 45 minute observation, he became unconsciousness. He was reintubated. Elevated procalcitonin (PCT) and endotoxin activity assay (EAA) brought us to the diagnosis of severe septic shock. He was treated by a standard therapy conforming to early goal direct therapy and PMX-DHP with CHDF. He showed full recovery, and was discharged 9 days after the procedure. TUL is commonly performed, but it seldom leads to sepsis. We need to pay a careful attention peri- and postoperatively.

The effect of borneol on the concentration of meropenem in rat brain and blood

Meropenem is a carbapenem antibiotic with a wide spectrum of activity against both Gram-positive and Gram-negative bacteria. Because of its clinical efficacy, meropenem is an excellent choice for the treatment of serious infections in both adults and children. The knowledge of tissue concentrations of antibiotic in an infection site is valuable for the prediction of treatment outcome. The aim of the present study is to investigate the effect of borneol on the concentration of meropenem in rat brain and blood and to find the potential relationships of the combined use of medicine and traditional Chinese medicine. Analysis of meropenem in the dialysates was achieved using the microdialysis technique and HPLC. At 40 min after the administration of an intraperitoneal injection of meropenem, the concentration of meropenem in brain in borneol+meropenem group was 2.25 (0.35) μg ml(-1), which was significantly higher than that in meropenem group [1.20 (0.12) μg ml(-1); P < 0.01]. Within 80 min of drug administration, the AUCbrain/AUCblood (area under the curve, AUC) in the borneol+meropenem group was 1.2 times that of the meropenem group. Borneol can increase the concentration of meropenem in the cerebrospinal fluid, but has no influence on its blood concentration. This study represents a successful application of the microdialysis technique, which is an effective method for the study of pharmacokinetics of meropenem.

In vitro efficacy of antibiotic beads in treating abdominal vascular graft infections

OBJECTIVE

Abdominal aortic vascular graft infection often involves several different organisms. Antibiotic polymethyl methacrylate (PMMA) beads may be effective in controlling infection after débridement, but bacterial species identification and antibiotic susceptibility are often not available at the time of operation, generating a need for a broad-spectrum drug combination for empirical use. We sought to determine an effective antibiotic in PMMA beads for use in abdominal vascular graft infection.

METHODS

PMMA beads were impregnated with combinations of antibiotics, consisting of daptomycin, tobramycin, and meropenem. Antibiotics were selected on the basis of activity spectrum and heat stability. Beads were placed on separate agar plates with vancomycin-resistant Enterococcus faecalis, Klebsiella pneumoniae, Staphylococcus epidermidis, and methicillin-resistant Staphylococcus aureus. Antibiotic inhibition was recorded by use of a modified agar-based disk-diffusion method.

RESULTS

Daptomycin alone was not active against K. pneumoniae (average = 0 mm). Tobramycin alone was not active against vancomycin-resistant E. faecalis, K. pneumoniae, or methicillin-resistant S. aureus. Tobramycin and daptomycin in combination had moderate broad-spectrum activity with 8- to 14-mm mean inhibition halos. Meropenem showed strong activity against all tested organisms with >15-mm mean inhibition halos. The addition of daptomycin to meropenem provided improved coverage of gram-positive organisms. The presence of tobramycin reduced the efficacy of meropenem.

CONCLUSIONS

Antibiotic PMMA beads containing 10% meropenem with 2.5% daptomycin had excellent in vitro activity against typical bacterial species associated with abdominal vascular graft infections. The addition of antibiotic beads may be a useful adjunct in managing such cases. Further studies are required to determine efficacy in clinical practice.

Development and validation of stability-indicating HPLC method for simultaneous determination of meropenem and potassium clavulanate

A stability-indicating LC assay method was developed and validated for a simultaneous determination of meropenem and potassium clavulanate in the presence of degradation products formed during acid-base hydrolysis, oxidation and thermolysis. The isocratic RP-HPLC method was developed with a LiChrospher RP-18 (250 mm x 4.6 mm, 5 microm) column and gradient elution of 12 mmol/L ammonium acetate and acetonitrile. The flow rate of the mobile phase was 1.0 mL/min, the detection wavelength 220 nm and the temperature 303 K. The method was validated with regard to linearity, accuracy, precision, selectivity and robustness, and was applied successfully for the determination of meropenem and potassium clavulanate separately as well as jointly in pharmaceutical formulations.

Pharmacodynamics of meropenem in critically ill patients with ventilator-associated pneumonia

BACKGROUND

Pharmacokinetic changes have been found in critically ill patients, including ventilator-associated pneumonia (VAP) when compared with healthy volunteers leading to fluctuation of plasma concentrations.

OBJECTIVE

To compare the probability of target attainment (PTA) and cumulative fraction of response (CFR) for meropenem between administration by a bolus injection and a 3-hour infusion.

MATERIAL AND METHOD

The study was a randomized three-way crossover in nine patients with VAP. Each patient received meropenem in three regimens consecutively: (i) a bolus injection of 1 g every eight hours (q8h) for 24 hours; (ii) a 3-hour infusion of 1 g q8h for 24 hours; and (iii) a 3-hour infusion of 2 g q8h for 24 hours. The pharmacodynamic analysis of meropenem was performed to determine the PTA by using the Monte Carlo simulation and the study used susceptibility patterns obtained from EUCAST and MYSTIC for assessment of CFR.

RESULTS

For an MIC of 4 microg/ml, the PTAs achieving 40% T > MIC following a bolus injection of 1 g q8h, a 3-hour infusion of 1 g q8h, and a 3-hour infusion of 2 g q8h were 87.71%, 98.80%, and 99.90%, respectively. Only the 3-hour infusion regimens were predicted to achieve a CFR > or = 90% against E. coli, Klebsiella spp., P. aeruginosa, and Acinetobacter spp.

CONCLUSION

A 3-hour infusion of 2 g of meropenem regimen was predicted to have the highest PTA rates. Only the prolonged infusion regimens achieved a high CFR against E. coli, Klebsiella spp., P. aeruginosa, and Acinetobacter spp.

Susceptibility to antibiotics of aerobic bacteria isolated from community acquired secondary peritonitis in children: therapeutic guidelines might not always fit with and everyday experience

Appendicitis is a frequent clinical condition in normal children that may be complicated by community-acquired secondary peritonitis (CASP). We evaluated the potential efficacy of different drugs for initial treatment of this condition, as recommended by recent Consensus Conference and Guidelines for paediatric patients. Susceptibility to ampicillin-sulbactam, ertapenem, gentamycin, piperacillin, piperacillin-tazobactam, vancomycin, and teicoplanin was evaluated according to EUCST 2012 recommendations in aerobic bacteria isolated from peritoneal fluid in CASP diagnosed from 2005 to 2011 at 'Istituto Giannina Gaslini', Genoa, Italy. A total of 114 strains were analysed: 83 E. coli, 15 P. aeruginosa, 6 Enterococci, and 10 other Gram-negatives. Resistance to ampicillin-sulbactam was detected in 37% of strains, while ertapenem showed a potential resistance of 13% (all P. aeruginosa strains). However, the combination of these drugs with gentamicin would have been increased the efficacy of the treatment to 99 and 100%, respectively. Resistance to piperacillin-tazobactam was 3%, while no strain was resistant to meropenem. Our data suggest that monotherapy with ampicillin-sulbactam or ertapenem for community-acquired secondary peritonitis would present a non-negligible rate of failure, but the addition of gentamycin to these drugs could reset to zero this risk. On the contrary, monotherapy with piperacillin-tazobactam or meropenem is highly effective.

Meropenem Monotherapy for the Treatment of Hospital- Acquired Pneumonia: Results of a Multicenter Trial

The efficacy and tolerability of meropenem as empirical treatment in patients with hospital-acquired pneumonia was determined in a prospective, open-label, non-randomized trial. Patients from 28 centers in the USA received meropenem 1 g every 8 h intravenously. Of 255 patients enrolled, 111 were evaluable for efficacy, including 60 patients with ventilator-associated pneumonia. At end of treatment 74% of patients had a satisfactory clinical response and 64% had this response at follow-up, which could last up to 28 days after treatment. In patients with ventilator-associated pneumonia, a satisfactory clinical response was observed in 68% at the end of treatment and 63% at follow-up. The overall satisfactory response rate for individual pretreatment pathogens ranged from 65% to 100%. This study demonstrates that meropenem monotherapy is effective and well tolerated for patients with hospital-acquired pneumonia, including a subgroup of patients with ventilator-associated pneumonia.

Adverse events associated with meropenem versus imipenem/cilastatin therapy in a large retrospective cohort of hospitalized infants

BACKGROUND

Carbapenems are commonly used in hospitalized infants despite a lack of complete safety data and associations with seizures in older children. We compared the incidence of adverse events in hospitalized infants receiving meropenem versus imipenem/cilastatin.

METHODS

We conducted a retrospective cohort study of 5566 infants treated with meropenem or imipenem/cilastatin in neonatal intensive care units managed by the Pediatrix Medical Group between 1997 and 2010. Multivariable conditional logistic regression was performed to evaluate the association between carbapenem therapy and adverse events, controlling for infant factors and severity of illness.

RESULTS

Adverse events were more common with use of meropenem compared with imipenem/cilastatin (62.8/1000 infant days versus 40.7/1000 infant days, P < 0.001). There was no difference in seizures with meropenem versus imipenem/cilastatin (adjusted odds ratio 0.96; 95% confidence interval: 0.68, 1.32). The incidence of death, as well as the combined outcome of death or seizure, was lower with meropenem use-odds ratio 0.68 (0.50, 0.88) and odds ratio 0.77 (0.62, 0.95), respectively.

CONCLUSION

In this cohort of infants, meropenem was associated with more frequent but less severe adverse events when compared with imipenem/cilastatin.

Workshop on treatment of and postexposure prophylaxis for Burkholderia pseudomallei and B. mallei Infection, 2010

The US Public Health Emergency Medical Countermeasures Enterprise convened subject matter experts at the 2010 HHS Burkholderia Workshop to develop consensus recommendations for postexposure prophylaxis against and treatment for Burkholderia pseudomallei and B. mallei infections, which cause melioidosis and glanders, respectively. Drugs recommended by consensus of the participants are ceftazidime or meropenem for initial intensive therapy, and trimethoprim/sulfamethoxazole or amoxicillin/clavulanic acid for eradication therapy. For postexposure prophylaxis, recommended drugs are trimethoprim/sulfamethoxazole or co-amoxiclav. To improve the timely diagnosis of melioidosis and glanders, further development and wide distribution of rapid diagnostic assays were also recommended. Standardized animal models and B. pseudomallei strains are needed for further development of therapeutic options. Training for laboratory technicians and physicians would facilitate better diagnosis and treatment options.

Bacillus cereus fasciitis: a unique pathogen and clinically challenging sequela of inoculation

Bacillus cereus is an aerobic, spore-forming, gram-positive rod. It has historically been associated with "fried rice syndrome," a foodborne diarrheal and emetic illness resulting from eating fried rice dishes that have been sitting at room temperature for hours. We report the case of a 9-year-old boy who developed culture-positive B cereus fasciitis of the right lower extremity after being impaled on a tree branch. This case report further elucidates and emphasizes the importance of recognizing B cereus as a possible cause of severe soft-tissue infection. It must be included in the differential diagnosis of gas gangrene and necrotizing fasciitis.

Bacillus cereus necrotizing pneumonia in a patient with nephrotic syndrome

Bacillus cereus (B. cereus) is a Gram-positive rod that is widely distributed in the environment and can be a cause of food poisoning. We herein present a case of B. cereus necrotizing pneumonia in a patient with nephrotic syndrome under corticosteroid treatment after developing transient gastroenteritis symptoms. B. cereus was isolated from bronchial lavage fluid and transbronchial biopsy specimens. A multiplex polymerase chain reaction analysis of the toxin genes revealed a strain possessing enterotoxicity. The patient recovered after one week of intravenous meropenem followed by a combination of oral moxifloxacin and clindamycin. B. cereus is a pathogen that causes necrotizing pneumonia in immunocompromised hosts.

[Bactericidal effect of levofloxacin injection in combination with meropenem against Pseudomonas aeruginosa using an in vitro simulation model with a hollow fiber system]

An in vitro human plasma concentration simulation model with a hollow fiber system was established and used to evaluate the bactericidal effect of levofloxacin (LVFX) 500mg q.d. in combination with meropenem (MEPM) 1000mg t.i.d. against Pseudomonas aeruginosa. Six clinical isolates of P. aeruginosa which had MEPM MICs of 2 - 16 microg/mL, LVFX MICs of 2 microg/mL, and fractional inhibitory concentration (FIC) indices by the in vitro checkerboard method of 0.625-1 were used. In the treatment with MEPM alone, initial viable counts (10(6)-10(7) CFU/ mL) decreased, but did not reach below the detection limit (100 CFU/mL) and the regrowth of bacteria was observed. In the treatment with LVFX alone, viable counts decreased once below the detection limit, although increased after treatment for 24 hours. On the other hand, in the treatment with LVFX-MEPM combination, more potent bactericidal effects were observed compared to LVFX or MEPM alone in all strains. Especially, in the strains with MEPM MICs of 2 and 4 microg/mL, viable counts rapidly decreased below the detection limit and no regrowth was observed until 24 hours. These results suggested that LVFX-MEPM has a potential to be an effective combination against P. aeruginosa by synergistic rapid bactericidal action in clinical settings, even in the strain against which no significant synergy is confirmed by the traditional in vitro checkerboard method.

Dosing nomograms for attaining optimum concentrations of meropenem by continuous infusion in critically ill patients with severe gram-negative infections: a pharmacokinetics/pharmacodynamics-based approach

The worrisome increase in Gram-negative bacteria with borderline susceptibility to carbapenems and of carbapenemase-producing Enterobacteriaceae has significantly undermined their efficacy. Continuous infusion may be the best way to maximize the time-dependent activity of meropenem. The aim of this study was to create dosing nomograms in relation to different creatinine clearance (CL(Cr)) estimates for use in daily clinical practice to target the steady-state concentrations (C(ss)s) of meropenem during continuous infusion at 8 to 16 mg/liter (after the administration of an initial loading dose of 1 to 2 g over 30 min). The correlation between meropenem clearance (CL(m)) and CL(Cr) was retrospectively assessed in a cohort of critically ill patients (group 1, n = 67) to create a formula for dosage calculation to target C(ss). The performance of this formula was validated in a similar cohort (group 2, n = 56) by comparison of the observed and the predicted C(ss)s. A significant relationship between CL(m) and CL(Cr) was observed in group 1 (r = 0.72, P < 0.001). The application of the formula to meropenem dosing in group 2, infusion rate (g/24 h) = [0.078 × CL(Cr) (ml/min) + 2.85] × target C(ss) × (24/1,000), led to a significant correlation between the observed and the predicted C(ss)s (r = 0.92, P < 0.001). Dosing nomograms based on CL(Cr) were created to target the meropenem C(ss) at 8, 12, and 16 mg/liter in critically ill patients. These nomograms could be helpful in improving the treatment of severe Gram-negative infections with meropenem, especially in the presence of borderline susceptible pathogens or even of carbapenemase producers and/or of pathophysiological conditions which may enhance meropenem clearance.

[A severe falciparum malaria case successfully treated by exchange transfusion as an adjunct therapy]

Plasmodium falciparum malaria is a type of malaria with high fatality rate despite optimal antimalarial treatment. Exchange transfusion (ET) is successfully used as a means of supportive therapy in severe P. falciparum malaria cases with hyperparasitemia. Herein, we present a case with hyperparasitemia, who received erythrocyte ET therapy due to lack of clinical response to antimalarial treatment. A 24-year-old male patient was admitted to our emergency clinic with the complaints of fever that persisted for 10 days, headache, nausea-vomiting, and impaired consciousness. Medical history revealed that he had been working in Sudan, Africa and returned back 12 days ago. On physical examination; he had fever, hypotension, tachycardia, subicterus and impaired cooperation. Laboratory examination revealed pancytopenia, elevated C-reactive protein, hyperbilirubinemia, hyponatremia, elevated creatinine level and hematuria. On thick blood smear and thin blood smear examinations, multiple (> 5%) trophozoites and gametocytes indicating P.falciparum species were observed. The case was diagnosed as P.falciparum malaria and parenteral fluid support, dopamine infusion, meropenem (IV), doxycycline (PO) and quinine sulphate (PO) were initiated in the intensive care unit. On reevaluation of the patient on the third day of hospitalization, it was observed that arterial hypotension and fever were persistent, anemia and trombocytopenia deteriorated and on thick blood smear parasitemiea was not decreased. It was decided to apply automated erythrocyte ET. After ET, patient's medical status was quickly improved and patient was discharged on the 7th day of hospitalization. In conclusion, it was noted that in addition to antimalarial treatment, erythrocyte ET may provide dramatic improvement in severe cases of P.falciparum malaria with hyperparasitemia.

Treating pneumonia in critical care in the United Kingdom following failure of initial antibiotic: a cost-utility analysis comparing meropenem with piperacillin/tazobactam

BACKGROUND

Treating patients admitted to critical care with severe pneumonia requires timely intervention with an effective antibiotic. This reduces the risk of dying of pneumonia and minimises complications associated with a prolonged stay in critical care.

OBJECTIVE

To compare the cost-effectiveness of meropenem 1 g/8 h with piperacillin/tazobactam 4.5 g/8 h for treating pneumonia in UK critical care.

METHODS

A Markov model was built to estimate lifetime costs and quality-adjusted life years (QALYs) of using meropenem versus piperacillin/tazobactam to treat severe pneumonia. Estimates of effectiveness, utility weights and costs were obtained from published sources. Probabilistic sensitivity analysis was conducted to address uncertainty in the model results.

RESULTS

Cost of treating a patient with severe pneumonia was estimated as £19,026 with meropenem and £19,978 with piperacillin/tazobactam, respectively. QALYs gained were 4.768 with meropenem and 4.654 with piperacillin/tazobactam. Probabilistic sensitivity analysis showed meropenem to be consistently less costly and more effective than piperacillin/tazobactam.

CONCLUSION

The additional efficacy of meropenem translates into more patients surviving critical care and leaving this high-cost service more quickly than if they had been treated with piperacillin/tazobactam. As meropenem is more effective and less expensive than piperacillin/tazobactam at treating patients with severe pneumonia, it is the dominant treatment option.

[Pharmacokinetics of meropenem administered with prolonged infusion time in patients receiving continuous veno-venous hemofiltration]

OBJECTIVE

To demonstrate the pharmacokinetic profile of meropenem when administered by 3-hour infusion in patients undergoing continuous veno-venous hemofiltration (CVVH).

METHODS

The study was conducted in 10 patients, who were treated with CVVH. Each subject received meropenem in 3-hour infusion of 500 mg every 6 hours. Blood samples were collected before infusion (0 hour) and 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 6 hours (just before the infusion of the next dose) after the beginning of the fourth infusion. The concentrations of meropenem in plasma were measured by high-performance liquid chromatography method, and mean serum meropenem concentration-time curve was plotted.

RESULTS

Peak plasma drug concentrations measured 3 hours post-infusion were (25.05 ± 5.64) mg/L, and trough levels after 6 hours of infusion were (13.03 ± 3.01) mg/L. The area under the plasma concentration-time curve (AUC) was (118.42 ± 26.78) mg x h⁻¹ x L⁻². The elimination half-life (T1/2) was (3.74 ± 0.55) hours. The mean residence time (MRT) was (4.99 ± 0.84) hours. The volume of distribution (Vb) was (22.85 ± 9.85) L and clearance of meropenem (CL) was (4.49 ± 1.32) L/h. The percentage of time that the serum drug concentration was above the minimum inhibitory concentration (MIC) accounting for the interval time of infusion (%T>MIC) was 100% (MIC 8 mg/L) in all the 10 patients.

CONCLUSION

Based on these data, we concluded that satisfactory pharmacodynamic parameters could be attained in CVVH patients treated with meropenem by a prolonged infusion time of 3 hours with a dosage of 500 mg for every 6 hours.

Effective antibiotics in combination against extreme drug-resistant Pseudomonas aeruginosa with decreased susceptibility to polymyxin B

OBJECTIVE

Extreme drug-resistant Pseudomonas aeruginosa (XDR-PA) with decreased susceptibility to polymyxin B (PB) has emerged in Singapore, causing infections in immunocompromised hosts. Combination therapy may be the only viable therapeutic option until new antibiotics become available. The objective of this study is to assess the in vitro activity of various antibiotics against local XDR-PA isolates.

METHODS

PA isolates from all public hospitals in Singapore were systematically collected between 2006 and 2007. MICs were determined according to CLSI guidelines. All XDR-PA isolates identified were genotyped using a PCR-based method. Time-kill studies (TKS) were performed with approximately 10(5) CFU/ml at baseline using clinically achievable unbound concentrations of amikacin (A), levofloxacin (L), meropenem (M), rifampicin (R) and PB alone and in combination. Bactericidal activity (primary endpoint) was defined as a ≥3 log(10) CFU/ml decrease in the colony count from the initial inoculum at 24 hours.

RESULTS

22 clinical XDR-PA isolates with PB MIC 2-16 µg/ml were collected. From clonal typing, 5 clonal groups were identified and nine isolates exhibited clonal diversity. In TKS, meropenem plus PB, amikacin plus meropenem, amikacin plus rifampicin, amikacin plus PB exhibited bactericidal activity in 8/22, 3/22, 1/22 and 6/22 isolates at 24 hours respectively. Against the remaining ten isolates where none of the dual-drug combination achieved bactericidal activity against, only the triple-antibiotic combinations of ARP and AMP achieved bactericidal activity against 7/10 and 6/10 isolates respectively.

CONCLUSION

Bactericidal activity with sustained killing effect of ≥99.9% is critical for eradicating XDR-PA infections, especially in immunocompromised hosts. These findings underscore the difficulty of developing combination therapeutic options against XDR-PA, demonstrating that at least 3 antibiotics are required in combination and that efficacy is strain dependant.

[Current clinical practice in the treatment of febrile neutropenia (FN)]

Because of the refractory and recurrent nature of febrile neutropenia (FN), definite diagnosis and early empiric treatment with antibiotics are important for FN patients. With this background, guidelines for FN treatment have been published in Japan and overseas, although a treatment method appropriate for clinical practice in Japan has not yet been established. Therefore, we conducted a survey of actual practice, including trends in prescription of antibiotics for FN, in the hope that it would help establish a definitive treatment for FN in Japan. The survey results confirmed that FN patients under care of hematology departments accounted for the largest proportion, followed by pediatrics (hematology), pulmonary medicine, medical oncology, and respiratory surgery, and the proportions of patients diagnosed with FN and those receiving antibiotics in hematology departments are larger than in other departments. Across all departments, cefepime (CFPM) is most frequently used as the initial treatment of choice, accounting for 35.9% of prescriptions, followed by meropenem (MEPM) (24.3%). These drugs are selected because they exhibit high potency and wide coverage against organisms that are presumed to cause FN, and their costs are covered by insurance, while the existence of insurance coverage is the major determining factor for treatment in Japan. Among second-line drugs, MEPM is most frequently used, accounting for 46.3% of prescriptions. The guidelines are commonly used as the basis for treatment, accounting for 52.0% of all departments, especially the guidelines established by the Japan Febrile Neutropenia Study Group. On the other hand, the percentage of departments that have introduced a hospital protocol and clinical path is only 13.0% in total. To provide appropriate treatment for FN patients, insurance coverage and introduction of a hospital protocol and clinical path based on guidelines and evidence are essential. The current situation, in which these are not implemented, is not desirable. The survey results show that the guidelines need to be revised to more closely reflect the actual situation in Japan and hospital protocols and clinical paths need to be introduced.

[Antibacterial therapy of severe intra-abdominal infections]

The experience of meropenem (Mepenam, manufactured by Corporation ARTERIUM, Ukraine) application as empirical therapy in severe intraabdominal infections was presented. The diseases outcome and the preparation efficacy were estimated, recommendations concerning its application in the treatment of severe intraabdominal infections were done.

[Case of meningitis caused by group B Streptococcus treated with high dose of meropenem]

We reported a case of meningitis caused by group B Streptococcus treated with high dose of meropenem (MEPM). A 67-year-old male was suffering from lumbago, fever up, vomiting and convulsion. He had received tumor resection of spinal cord at 40 years old. At the first consultation to our hospital, he had felt strong neck stiffness with Glasgow Coma Scale 5 (El, V1, M3), and his body temperature was 37.0 degrees C. His laboratory findings were as follows; white blood cell count 14600/microL, C-reactive protein 4.39mg/dL, and marked elevation of the cell count in the cerebrospinal fluid. We had administered high dose of meropenem, 6 g/day, and also vancomycin (VCM) on therapeutic drug monitoring. Since his clinical symptoms and laboratory findings had not shown adequate response after 4 days later, we had changed VCM to linezolid 1200 mg/day, and had also continued MEPM, which had resulted in prompt resolution of the clinical symptoms and laboratory findings. Microbiological examination for cerebrospinal fluid has yielded a growth of serotype III group B Streptococcus (Streptococcus agalactiae). Since there have been few data on 6 g/day MEPM against meningitis in spite of recommendation in several guidelines, further studies would be necessary including pharmacokinetic-pharmacodynamic analysis.

[Successful treatment of brain stem and thalamic abscesses with high-dose meropenem]

The incidence of brain abscess remains high, despite the development of novel antibiotics. Vancomycin or carbapenems, which are third-generation cephems, are recommended as standard therapy for bacterial meningitis or brain abscess. The effectiveness of the high-dose meropenem therapy on brain abscess has occasionally been reported. We experienced 2 consecutive cases of brain abscess in adults. The first patient was a 67-year-old man with diplopia, dizziness, and dysesthesia on the left upper and lower extremities. Images of T1-weighted magnetic resonance imaging (MRI) with contrast medium and diffusion-weighted MRI showed a ring enhancing cystic lesion and a high intensity lesion, respectively, in the right pons. The second patient was a 37-year-old man who complained of right hemiparesis. MRI revealed a ring-enhancing cystic mass in the left thalamus. On the basis of MRI findings, patients were diagnosed with brain abscess and were given high-dose meropenem (6g/day) continuously for 2 months. The abscess resolved completely after treatment with meropenem administered intravenously. Further, neurological deficits caused by abscess successfully improved. High-dose meropenem therapy should be considered as an effective treatment for brain abscess, even in the brain stem and basal ganglia, where it is quite difficult to achieve surgical access.