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Background: Antibiotic overuse leads to the emergence of antibiotic resistance that threatens immunocompromised cancer patients. Infections caused by MDR Gram-negative pathogens are difficult to treat and associated with high mortality. Hence, empirical therapy with standard-of-care (SOC) antibiotics could be suboptimal in these vulnerable patients. New antibiotics covering potential resistant pathogens may be considered., Methods: We conducted a randomized non-inferiority study comparing safety and efficacy of imipenem/cilastatin/relebactam (IPM/REL), a β-lactam/β-lactamase inhibitor combination, with SOC antibiotics (cefepime, piperacillin/tazobactam or meropenem) in cancer patients with febrile neutropenia. Patients received at least 48 h of IV antibiotics and were assessed at end-of-IV (EOIV) therapy, test of cure (TOC; Days 21-28), and late follow-up (LFU; Days 35-42)., Results: A total of 100 patients were enrolled (49 IPM/REL and 50 SOC). Demographics and rates of documented microbiological infections were similar in both groups. In the SOC arm, 86% of antibiotics consisted of cefepime. Patients on IPM/REL had a higher favourable clinical response at EOIV than those on SOC (90% versus 74%; P = 0.042); however, responses were similar at TOC and LFU. Microbiological eradication was comparable at all three timepoints. Study drug-related adverse events and adverse events leading to drug discontinuation were similar in both groups, with no study drug-related mortality., Conclusions: Our results suggest that compared with SOC antibiotics, predominantly cefepime, IPM/REL for empirical coverage of febrile neutropenia in cancer patients is generally safe and could be associated with a better clinical outcome at EOIV. The current SOC consisting mainly of agents that do not cover for ESBL-producing and carbapenem-resistant Enterobacterales bacteria should be reconsidered., (© The Author(s) 2024. Published by Oxford University Press on behalf of British Society for Antimicrobial Chemotherapy. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Imipenem/cilastatin/relebactam is approved for the treatment of serious gram-negative bacterial infections in adults. This study assessed the pharmacokinetics (PK), safety, and tolerability of a single dose of imipenem/cilastatin/relebactam (with a fixed 2:1 ratio of imipenem/cilastatin to relebactam, and with a maximum dose of 15 mg/kg imipenem and 15 mg/kg cilastatin [≤500 mg imipenem and ≤500 mg cilastatin] and 7.5 mg/kg relebactam [≤250 mg relebactam]) in children with confirmed/suspected gram-negative bacterial infections receiving standard-of-care antibacterial therapy. In this phase 1, noncomparative study (ClinicalTrials.gov identifier, NCT03230916), PK parameters from 46 children were analyzed using both population modeling and noncompartmental analysis. The PK/pharmacodynamic (PD) target for imipenem was percent time of the dosing interval that unbound plasma concentration exceeded the minimum inhibitory concentration (%fT>MIC) of ≥30% (MIC = 2 mcg/mL). For relebactam, the PK/PD target was a free drug area under the plasma concentration-time curve (AUC) normalized to MIC (at 2 mcg/mL) of ≥8.0 (equivalent to an AUC from time zero extrapolated to infinity of ≥20.52 mcg·h/mL). Safety was assessed up to 14 days after drug infusion. For imipenem, the ranges for the geometric mean %fT>MIC and maximum concentration (C max ) across age cohorts were 56.5%-93.7% and 32.2-38.2 mcg/mL, respectively. For relebactam, the ranges of the geometric mean C max and AUC from 0 to 6 hours across age cohorts were 16.9-21.3 mcg/mL and 26.1-55.3 mcg·h/mL, respectively. In total, 8/46 (17%) children experienced ≥1 adverse events (AEs) and 2/46 (4%) children experienced nonserious AEs that were deemed drug related by the investigator. Imipenem and relebactam exceeded plasma PK/PD targets; single doses of imipenem/cilastatin/relebactam were well tolerated with no significant safety concerns identified. These results informed imipenem/cilastatin/relebactam dose selection for further pediatric clinical evaluation., (© 2023 The Authors. The Journal of Clinical Pharmacology published by Wiley Periodicals LLC on behalf of American College of Clinical Pharmacology.)

Purpose: To evaluate the effectiveness and safety of intra-arterial imipenem/cilastatin sodium (IPM/CS) infusion for painful interphalangeal joint osteoarthritis (OA)., Materials and Methods: Fifty-eight patients with interphalangeal joint OA who underwent intra-arterial IPM/CS infusion were retrospectively evaluated. Intra-arterial infusions were performed via percutaneous wrist arterial access. The Numerical Rating Scale (NRS), Functional Index for Hand Osteoarthritis (FIHOA), and Patient Global Impression of Change (PGIC) scale scores were assessed at intervals of 1, 3, 6, 12, and 18 months. Clinical success was evaluated based on PGIC., Results: All patients were followed up for at least 6 months after treatment. Of them, 30 and 6 patients were followed up for 12 and 18 months, respectively. No severe or life-threatening adverse events were encountered. The mean NRS score was 6.0 ± 1.4 at baseline, which significantly decreased to 2.8 ± 1.4, 2.2 ± 1.9, and 2.4 ± 1.9 at 1, 3, and 6 months after treatment, respectively (all P < .001). The mean NRS scores were 2.8 ± 1.7 and 2.9 ± 1.9 at 12 and 18 months, respectively, in the remaining patients. The mean FIHOA score significantly decreased from 9.8 ± 5.0 at the baseline to 4.1 ± 3.5 at 3 months (P < .001). The mean FIHOA score was 4.5 ± 3.3 at 12 months in the remaining 30 patients. The clinical success rates based on PGIC at 1, 3, 6, 12, and 18 months were 62.1%, 77.6%, 70.7%, 63.4%, and 50.0%, respectively., Conclusions: Intra-arterial IPM/CS infusion is a potential treatment option for interphalangeal joint OA refractory to medical management., (Copyright © 2023. Published by Elsevier Inc.)

Imipenem cilastatin sodium, as a member of a new generation of β-lactam antibiotics, has a broad spectrum of antibacterial activity and a very wide range of application. Thrombocytopenia has been reported as a rare adverse event in several studies of patients treated with imipenem cilastatin sodium. In this study, we present a case of thrombocytopenia associated with imipenem cilastatin sodium in an older patient. The 78-year-old male patient with pulmonary infection was initiated on anti-infection therapy with imipenem cilastatin sodium. On the 9 th day after imipenem cilastatin sodium administration, the patient experienced a sudden and dramatic decrease in platelet count. Similarly, on the 4 th day after the re-administration of imipenem cilastatin sodium for anti-infection therapy, the patient's platelet count showed a remarkable downward trend again. A time correlation between the drug therapy and the occurrence of platelet reaction was found. The patient's platelet count gradually returned to the normal level on the 6 th day after the first drug withdrawal and the 13 th day after the second drug withdrawal, respectively. Considering the widespread use of imipenem cilastatin sodium, healthcare providers should improve the notification of thrombocytopenia associated with imipenem cilastatin sodium.

Background: Imipenem combined with the β-lactamase inhibitor relebactam has broad antibacterial activity, including against carbapenem-resistant gram-negative pathogens. We evaluated efficacy and safety of imipenem/cilastatin/relebactam in treating hospital-acquired/ventilator-associated bacterial pneumonia (HABP/VABP)., Methods: This was a randomized, controlled, double-blind phase 3 trial. Adults with HABP/VABP were randomized 1:1 to imipenem/cilastatin/relebactam 500 mg/500 mg/250 mg or piperacillin/tazobactam 4 g/500 mg, intravenously every 6 hours for 7-14 days. The primary endpoint was day 28 all-cause mortality in the modified intent-to-treat (MITT) population (patients who received study therapy, excluding those with only gram-positive cocci at baseline). The key secondary endpoint was clinical response 7-14 days after completing therapy in the MITT population., Results: Of 537 randomized patients (from 113 hospitals in 27 countries), the MITT population comprised 264 imipenem/cilastatin/relebactam and 267 piperacillin/tazobactam patients; 48.6% had ventilated HABP/VABP, 47.5% APACHE II score ≥15, 24.7% moderate/severe renal impairment, 42.9% were ≥65 years old, and 66.1% were in the intensive care unit. The most common baseline pathogens were Klebsiella pneumoniae (25.6%) and Pseudomonas aeruginosa (18.9%). Imipenem/cilastatin/relebactam was noninferior (P < .001) to piperacillin/tazobactam for both endpoints: day 28 all-cause mortality was 15.9% with imipenem/cilastatin/relebactam and 21.3% with piperacillin/tazobactam (difference, -5.3% [95% confidence interval {CI}, -11.9% to 1.2%]), and favorable clinical response at early follow-up was 61.0% and 55.8%, respectively (difference, 5.0% [95% CI, -3.2% to 13.2%]). Serious adverse events (AEs) occurred in 26.7% of imipenem/cilastatin/relebactam and 32.0% of piperacillin/tazobactam patients; AEs leading to treatment discontinuation in 5.6% and 8.2%, respectively; and drug-related AEs (none fatal) in 11.7% and 9.7%, respectively., Conclusions: Imipenem/cilastatin/relebactam is an appropriate treatment option for gram-negative HABP/VABP, including in critically ill, high-risk patients., Clinical Trials Registration: NCT02493764., (© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America.)

Purpose: The pharmacology, pharmacokinetics, pharmacodynamics, antimicrobial activity, efficacy, safety, and current regulatory status of imipenem/cilastatin/relebactam are reviewed., Summary: Imipenem/cilastatin/relebactam is a newly approved anti-infective combination of a well-established β-lactam and a new β-lactamase inhibitor for the treatment of complicated urinary tract infections (cUTIs), including pyelonephritis, and complicated intra-abdominal infections (cIAIs) caused by susceptible gram-negative bacteria in patients 18 years of age or older with limited or no alternative treatment options. The antibiotic is also indicated for the treatment of hospital-acquired bacterial pneumonia (HABP) and ventilator-associated bacterial pneumonia (VABP). The antibiotic is active in vitro against a wide range of pathogens, including multidrug-resistant (MDR) Pseudomonas aeruginosa and carbapenem-resistant Enterobacterales (CRE) such as Klebsiella pneumoniae carbapenemase. The addition of relebactam does not restore the activity of imipenem against metallo-β-lactamase (MBL)-producing Enterobacterales and carbapenem-resistant Acinetobacter baumannii. Two phase 3 clinical trials of imipenem/cilastatin/relebactam were conducted. In the RESTORE-IMI 1 trial, the efficacy and safety of imipenem/cilastatin/relebactam was found to be comparable to that of imipenem/cilastatin plus colistin for the treatment of infections caused by imipenem-nonsusceptible gram-negative bacteria in patients with HABP/VABP, cUTIs, and cIAIs, with a significantly lower incidence of nephrotoxicity reported with the new antibiotic. The RESTORE-IMI 2 trial demonstrated the noninferiority of imipenem/cilastatin/relebactam to piperacillin/tazobactam for the treatment of HABP/VABP. Commonly reported adverse events in clinical trials included anemia, elevated liver enzymes, electrolyte imbalances, nausea, vomiting, diarrhea, headache, fever, phlebitis and/or infusion-site reactions, and hypertension., Conclusion: Imipenem/cilastatin/relebactam is a new β-lactam/β-lactamase inhibitor combination with activity against MDR gram-negative bacteria, including many CRE but excluding MBL-producing Enterobacterales and carbapenem-resistant Acinetobacter baumannii. It is approved for the treatment of cUTIs, cIAIs, and HABP/VABP., (© American Society of Health-System Pharmacists 2021. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Relebactam/imipenem/cilastatin is approved in the United States to treat complicated urinary tract and intra-abdominal infections in patients who have limited or no alternative treatment options and hospital-acquired bacterial pneumonia (HABP)/ventilator-associated bacterial pneumonia (VABP). Initial pharmacokinetic, safety, and tolerability studies of relebactam with and without imipenem/cilastatin included mostly Caucasian participants. This study evaluated the pharmacokinetics, safety, and tolerability of relebactam/imipenem/cilastatin in 12 healthy Chinese participants after three single doses of increasing concentrations (relebactam at 125, 250, or 500 mg; cilastatin at 250, 500, or 1,000 mg; and imipenem at 250, 500, or 1,000 mg) and after multiple doses every 6 h of a single concentration (relebactam at 250 mg, cilastatin at 500 mg, and imipenem at 500 mg) for 14 days. After single doses, the area under the concentration-time curve (AUC) extrapolated to infinity (relebactam, 15.0 to 70.7 h · mg/liter; imipenem, 24.1 to 109.8 h · mg/liter; cilastatin, 18.4 to 95.3 h · mg/liter) and the AUC from 0 to 6 h (relebactam, 14.2 to 66.3 h · mg/liter; imipenem, 23.4 to 107.3 h · mg/liter; cilastatin, 18.3 to 94.4 h · mg/liter) increased in a dose-dependent manner; clearance (relebactam, 6.9 to 8.3 liters/h; imipenem, 8.6 to 10.4 liters/h; cilastatin, 10.5 to 13.6 liters/h) and half-life (relebactam, 1.4 to 1.6 h; imipenem, 1.0 to 1.2 h; cilastatin, 0.7 to 1.0 h) were consistent between doses. Pharmacokinetic parameters after multiple doses were similar to parameters after a single dose (geometric mean ratios of 0.8 to 1.0 for all three agents). Relebactam/imipenem/cilastatin was well tolerated; mild adverse events occurred during single dosing, and one participant experienced serious adverse events after multiple doses. Pharmacokinetics and safety data are comparable with data from participants of other ethnicities, supporting the use of relebactam/imipenem/cilastatin at the approved dose and schedule in Chinese patients., (Copyright © 2021 American Society for Microbiology.)

Introduction: Relebactam, a novel class A/C β-lactamase inhibitor developed as a fixed-dose combination with imipenem/cilastatin, restores imipenem activity against imipenem-nonsusceptible gram-negative pathogens., Methods: This phase 3, multicenter, open-label, noncomparative study (NCT03293485) evaluated relebactam/imipenem/cilastatin (250 mg/500 mg/500 mg) dosed every 6 h for 5-14 days in Japanese patients with complicated intra-abdominal infections (cIAIs) or complicated urinary tract infections (cUTIs), including those with secondary sepsis. Sepsis was defined as an infection-induced systemic inflammatory response syndrome, with a documented positive blood culture; patients meeting these protocol-defined criteria were evaluated for efficacy against sepsis., Results: Of 83 patients enrolled, 81 patients (cIAI, n = 37; cUTI, n = 44) received ≥1 dose of study treatment. Escherichia coli was the most common baseline pathogen isolated in both patients with cIAI and cUTI. Adverse events (AEs) were reported in 74.1% (n = 60/81) of patients, and drug-related AEs occurred in 18.5% (n = 15/81). The most common AEs were diarrhea and nausea (8.6%). Serious AEs occurred in nine patients, including one death, but none were considered treatment related. The primary efficacy endpoint for patients with cIAI was clinical response at end of treatment (EOT) in the microbiologically evaluable (ME) population, and for patients with cUTI was microbiological response at EOT in the ME population. The proportion of cIAI and cUTI patients achieving favorable responses were 85.7% (n = 24/28) and 100.0% (n = 39/39), respectively. All patients with sepsis (cIAI, n = 1; cUTI, n = 5) achieved a favorable composite clinical and microbiological response at EOT., Conclusions: A favorable safety and efficacy profile for relebactam/imipenem/cilastatin was observed in Japanese patients with cIAI and cUTI., Competing Interests: Declaration of competing interest SK was a coordinating investigator in this trial. HB, FY, HK, and KK participated as an investigator in this trial. SK, HB, FY, HK, and KK received compensation for the preparation of this manuscript from MSD K.K. MS, NA, and AT are employees of Japan Development, MSD K.K., Tokyo, Japan, and MB and AP are employees of Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, New Jersey, USA, who may own stock and/or hold stock options in Merck & Co., Inc., Kenilworth, NJ, USA. Funding for this research was provided by MSD K.K., Tokyo, Japan., (Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Aims: Two phase 1, open-label studies were conducted to investigate the effect of renal impairment (RI) and organic anion transporter (OAT) inhibition on pharmacokinetics (PK) and safety of relebactam (REL) plus imipenem/cilastatin (IMI)., Methods: Study PN005 evaluated the PK of REL (125 mg) plus IMI (250 mg) in participants with RI vs healthy controls. Study PN019 evaluated the PK of REL (250 mg) and imipenem (500 mg; dosed as IMI) with/without probenecid (1 g; OAT inhibitor) in healthy adults., Results: Geometric mean ratios (RI/healthy matched controls) of area under the concentration-time curve from time 0 to infinity (AUC 0-∞ ; 90% confidence interval) for REL, imipenem and cilastatin increased as RI increased from mild (1.6 [1.1, 2.4], 1.4 [1.1, 1.8] and 1.6 [1.0, 2.5], respectively) to severe (4.9 [3.4, 7.0], 2.5 [1.9, 3.3] and 5.6 [3.6, 8.6], respectively). For all 3 analytes, plasma and renal clearance decreased and corresponding plasma apparent terminal half-life increased with increasing RI. Geometric mean ratios ([probenecid+IMI/REL]/[IMI/REL]) of plasma exposure for REL and imipenem were 1.24 (1.19, 1.28) and 1.16 (1.13, 1.20), respectively. The dose fraction excreted (fe) in the urine decreased progressively from mild to severe RI. Probenecid reduced renal clearance of REL and imipenem by 25 and 31%, respectively. Compared with IMI/REL, coadministration of IMI/REL with probenecid yielded lower fe for REL and imipenem. In both studies, treatment was well tolerated; there were no serious adverse events or discontinuations due to adverse events., Conclusion: RI increased plasma exposure and similarly decreased clearance of REL, imipenem and cilastatin; IMI/REL dose adjustment (fixed-ratio) will be required for patients with RI. Probenecid had no clinically meaningful impact on the PK of REL or imipenem., (© 2019 The British Pharmacological Society.)

Objectives: The primary objective of this study was to establish a novel method to assess the effect of imipenem/cilastatin (IMP) on liver function laboratory indexes in Chinese underage inpatients (inpatients aged <18 year-old)., Methods: A retrospective study was conducted in 188 underage inpatients who received IMP in Xiangya Hospital from January 2016 to April 2018. Demographic data and clinical information of these inpatients were collected. As there was no reference interval of minors, the occurrence of abnormal liver function was estimated by that of adults, temporarily. A new concept (mean-variance induced by drug, MVID) was introduced to analyze the characteristics of total bilirubin (TBil), direct bilirubin (DBil), alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Effect of MVID of TBil, DBil, ALT and AST in different patients (aged<1 year old and aged ≥ 1 year old) were compared by Mann-Whitney U test., Results: Estimating by reference intervals of adults, 57.4% underage inpatients (108/188) had abnormal liver function. According to the probability distribution curve of MVID, IMP can cause the increase of AST in 24% (0.62-0.38) Chinese underage inpatients, and the increase of ALT in 20% (0.60-0.40) Chinese underage inpatients. And liver protecting drugs can decrease MVID of ALT and AST. There were not statistically significant differences in MVID of TBil, DBil, ALT and AST in different patients (aged<1 year old and aged ≥ 1 year old); P value was 0.711, 0.734, 0.067 and 0.086, respectively., Conclusion: IMP can affect the liver function of 20-24% Chinese underage inpatients mainly by increasing the AST and ALT. IMP may induce hepatocellular injury, but not cholestasis. And liver protecting drugs can reverse the side effects caused by IMP. Age may not affect the effect of IMP on liver function., Competing Interests: The authors have declared that no competing interests exist.

Background: Burn patients are prone to infections which often necessitate broad antibiotic coverage. Vancomycin is a common antibiotic after burn injury and is administered alone (V), or in combination with imipenem-cilastin (V/IC) or piperacillin-tazobactam (V/PT). Sparse reports indicate that the combination V/PT is associated with increased renal dysfunction. The purpose of this study was to evaluate the short-term impact of the three antibiotic administration types on renal dysfunction., Methods: All pediatric and adult patients admitted to our centers between 2004 and 2016 with a burn injury were included in this retrospective review if they met the criteria of exposition to either V, V/IC, or V/PT for at least 48 h, had normal baseline creatinine, and no pre-existing renal dysfunction. Creatinine was monitored for 7 days after initial exposure; the absolute and relative increase was calculated, and patient renal outcomes were classified according to the Kidney Disease Improving Global Outcomes (KDIGO) criteria depending on creatinine increases and estimated creatinine clearance. Secondary endpoints (demographic and clinical data, incidences of septicemia, and renal replacement therapy) were analyzed. Antibiotic doses were modeled in logistic and linear multivariable regression models to predict categorical KDIGO events and relative creatinine increase., Results: Out of 1449 patients who were screened, 718 met the inclusion criteria, 246 were adults, and 472 were children. Between the study cohorts V, V/IC, and V/PT, patient characteristics at admission were comparable. V/PT administration was associated with a statistically higher serum creatinine, and lower creatinine clearance compared to patients receiving V alone or V/IC in adults and children after burn injury. The incidence of KDIGO stages 1, 2, and 3 was higher after V/PT treatment. In children, the incidence of KDIGO stage 3 following administration of V/PT was greater than after V/IC. In adults, the incidence of renal replacement therapy was higher after V/PT compared with V or V/IC. Multivariate modeling demonstrated that V/PT is an independent predictor of renal dysfunction., Conclusion: Co-administration of vancomycin and piperacillin-tazobactam is associated with increased renal dysfunction in pediatric and adult burn patients when compared to vancomycin alone or vancomycin plus imipenem-cilastin. The mechanism of this increased nephrotoxicity remains elusive and warrants further scientific evaluation.

Objectives: The β-lactamase inhibitor relebactam can restore imipenem activity against imipenem non-susceptible pathogens., Methods: To explore relebactam's safety, tolerability and efficacy, we conducted a randomized (1:1:1), controlled, Phase 2 trial comparing imipenem/cilastatin+relebactam 250 mg, imipenem/cilastatin+relebactam 125 mg and imipenem/cilastatin alone in adults with complicated urinary tract infections (cUTI) or acute pyelonephritis, regardless of baseline pathogen susceptibility. Treatment was administered intravenously every 6 h for 4-14 days, with optional step-down to oral ciprofloxacin. The primary endpoint was favourable microbiological response rate (pathogen eradication) at discontinuation of intravenous therapy (DCIV) in the microbiologically evaluable (ME) population. Non-inferiority of imipenem/cilastatin+relebactam over imipenem/cilastatin alone was defined as lower bounds of the 95% CI for treatment differences being above -15%., Results: At DCIV, 71 patients in the imipenem/cilastatin + 250 mg relebactam, 79 in the imipenem/cilastatin + 125 mg relebactam and 80 in the imipenem/cilastatin-only group were ME; 51.7% had cUTI and 48.3% acute pyelonephritis. Microbiological response rates were 95.5%, 98.6% and 98.7%, respectively, confirming non-inferiority of both imipenem/cilastatin + relebactam doses to imipenem/cilastatin alone. Clinical response rates were 97.1%, 98.7% and 98.8%, respectively. All 23 ME patients with imipenem non-susceptible pathogens had favourable DCIV microbiological responses (100% in each group). Among all 298 patients treated, 28.3%, 29.3% and 30.0% of patients, respectively, had treatment-emergent adverse events. The most common treatment-related adverse events across groups (1.0%-4.0%) were diarrhoea, nausea and headache., Conclusions: Imipenem/cilastatin + relebactam (250 or 125 mg) was as effective as imipenem/cilastatin alone for treatment of cUTI. Both relebactam-containing regimens were well tolerated. (NCT01505634)., (© The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Background: Elderly patients, in particular, have been reported to develop psychiatric side effects from antibiotics. Clarithromycin, quinolones, sulfamethoxazole-trimethoprim, isoniazid, penicillin, and cephalosporins have been reported to cause psychosis. This case report bridges a void in the medical literature with regards to the psychiatric adverse effects of imipenem-cilastatin., Case Presentation: A 64-year-old Hispanic man in septic shock due to urinary tract infection was initiated on imipenem-cilastatin and mechanically ventilated, following admission to hospital. His mentation was normal for 72 hours after extubation and discontinuation of sedatives and opioids, following which he was noted to be in acute psychosis. Our patient's imipenem-cilastatin dose had been increased 24 hours prior to his violent visual and auditory hallucinations because his renal function had improved. The physical examination and laboratory tests did not reveal evidence of a new central nervous infection or endocrinopathy. His mentation improved after his antibiotic was switched to ceftriaxone, based on culture and sensitivity testing. Similar psychiatric symptoms developed 2 months later when he was treated with imipenem for a recurrent urinary tract infection. His symptoms again resolved with modification of his antibiotic regimen., Conclusions: Endocrine dysfunctions (thyroid, adrenal, and pituitary disorders) and toxic ingestions are medical disorders known to cause brief psychotic episodes. Fluoroquinolones, penicillins, and trimethoprim-sulfamethoxazole are common antibiotics associated with this rare adverse effect. Several pharmacokinetic hypotheses have been proposed for this adverse effect: (1) N-methyl-D-aspartate receptor hypofunctioning, (2) sequential blockade of folic acid production, (3) inhibition of prostaglandin E2 and proinflammatory cytokine production, (4) increased central dopamine turnover, and (5) accumulation of toxic levels of the drug. Pre-existing psychopathology, relevant comorbidities, slow acetylation status, and increased permeability of the blood-brain barrier have been suggested to make patients more prone to developing psychosis. According to the literature, this psychiatric manifestation resolves within 2 weeks of discontinuing the offending agent. There appears to be underreporting of the psychiatric manifestations of imipenem-cilastatin, contrary to post-marketing surveillance data. It is imperative that physicians recognize these psychiatric side effects of antibiotics, because they are a fundamental treatment option.

Drugs, toxins, and infections are known to cause acute eosinophilic pneumonia. Daptomycin and minocycline are the commonly reported antibiotics associated with acute eosinophilic pneumonia. In this study, we present a case of imipenem/cilastatin-induced acute eosinophilic pneumonia. The patient presented with fever, acute hypoxic respiratory distress, and diffuse ground-glass opacities on the chest CT a day after the initiation of imipenem/cilastatin. Patient also developed peripheral eosinophilia. A reinstitution of imipenem/cilastatin resulted in recurrence of the signs and symptoms. A bronchoscopy with bronchoalveolar lavage showed 780 nucleated cells/mm(3) with 15% eosinophil. The patient's clinical condition improved significantly after the discontinuation of imipenem/cilastatin therapy and the treatment with corticosteroid., (2016 BMJ Publishing Group Ltd.)

The present study is a non-inferiority study based on a descriptive and comparative case series for comparison of generic vs. original intravenous antimicrobials in septic oncology patients at an oncology private ICU. 1906 cancer patients admitted to Arturo Lopez Perez Foundation, Chile, were included in this study. After recruitment, a first retrospective group of 206 septic cancer patients recorded from 1st January, 2008 until July 14th, 2010, treated with original antibiotics (cefoperazone-sulbactam, imipenem-cilastatin, piperacillin-tazobactam) were included for analyses and a second prospective group of 143 septic cancer patients recorded from July 15th, 2010 until January 02, 2013, treated with the same but generic antibiotics were also included for comparisons. The trial protocol was developed in accordance with Helsinki and Good Clinical Practices recommendations. The results of this study showed no significant differences between the 2 groups in days of treatment, rate of success and lab test determinations (white cell count, PCR and procalcitonin), with lower, but not significant, total bed days and CPU bed days for generic antibiotics. Therefore, we conclude that the safety and efficacy of the generic antibiotics cefactam®, imipen® and Piperazam® are not inferior to original antibiotics for the treatment of severe sepsis in hospitalised patients at the Arturo Lopez Perez Foundation., (© Georg Thieme Verlag KG Stuttgart · New York.)

The efficacy and toxicity of several drugs now used to treat multidrug-resistant tuberculosis (MDR-TB) have not been fully evaluated. We searched three databases for studies assessing efficacy in MDR-TB or safety during prolonged treatment of any mycobacterial infections, of drugs classified by the World Health Organization as having uncertain efficacy for MDR-TB (group 5). We included 83 out of 4002 studies identified. Evidence was inadequate for meropenem, imipenem and terizidone. For MDR-TB treatment, clarithromycin had no efficacy in two studies (risk difference (RD) -0.13, 95% CI -0.40-0.14) and amoxicillin-clavulanate had no efficacy in two other studies (RD 0.07, 95% CI -0.21-0.35). The largest number of studies described prolonged use for treatment of non-tuberculous mycobacteria. Azithromycin was not associated with excess serious adverse events (SAEs). Clarithromycin was not associated with excess SAEs in eight controlled trials in HIV-infected patients (RD 0.00, 95% CI -0.02-0.02), nor in six uncontrolled studies in HIV-uninfected patients, whereas six uncontrolled studies in HIV-infected patients clarithromycin caused substantial SAEs (proportion 0.20, 95% CI 0.12-0.27). For most group 5 drugs we found inadequate evidence of safety for prolonged use or for efficacy for MDR-TB, although macrolides appeared to be safe in prolonged use., (Copyright ©ERS 2015.)

French guidelines recommend central intravenous (i.v.) infusion for high concentrations of vancomycin, but peripheral intravenous (p.i.v.) infusion is often preferred in intensive care units. Vancomycin infusion has been implicated in cases of phlebitis, with endothelial toxicity depending on the drug concentration and the duration of the infusion. Vancomycin is frequently infused in combination with other i.v. antibiotics through the same administrative Y site, but the local toxicity of such combinations has been poorly evaluated. Such an assessment could improve vancomycin infusion procedures in hospitals. Human umbilical vein endothelial cells (HUVEC) were challenged with clinical doses of vancomycin over 24 h with or without other i.v. antibiotics. Cell death was measured with the alamarBlue test. We observed an excess cellular death rate without any synergistic effect but dependent on the numbers of combined infusions when vancomycin and erythromycin or gentamicin were infused through the same Y site. Incompatibility between vancomycin and piperacillin-tazobactam was not observed in our study, and rinsing the cells between the two antibiotic infusions did not reduce endothelial toxicity. No endothelial toxicity of imipenem-cilastatin was observed when combined with vancomycin. p.i.v. vancomycin infusion in combination with other medications requires new recommendations to prevent phlebitis, including limiting coinfusion on the same line, reducing the infusion rate, and choosing an intermittent infusion method. Further studies need to be carried out to explore other drug combinations in long-term vancomycin p.i.v. therapy so as to gain insight into the mechanisms of drug incompatibility under multidrug infusion conditions., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)

Background: We conducted a randomized controlled trial to evaluate the clinical efficacy and safety of intravenous doripenem (DRPM) in patients with biliary tract infection requiring biliary drainage in comparison with imipenem/cilastatin (IPM/CS)., Methods: After the initial collection of bile, patients were randomly assigned by the registration system of the Clinical Research Organization to receive intravenous drip infusion of DRPM 0.5 g or IPM/CS 0.5 g three times daily in a randomized, open-label manner., Results: A total of 127 patients were enrolled in the trial (DRPM 62, IPM/CS 65). The characteristics of the 122 patients evaluated for efficacy were well balanced, except for the percentage of patients previously receiving antimicrobials, which was higher in the DRPM group than in the IPM/CS group. The clinical response rate was not significantly different between the DRPM group (93.1 %, 54/58 patients) and the IPM/CS group (93.8 %, 60/64). Non-inferiority assessment using confidence intervals demonstrated the non-inferiority of DRPM-IPM/CS. The incidence of adverse events, for which a causal relationship with either treatment was not ruled out, was 3.3 % (2/60) in the DRPM group and 3.1 % (2/65) in the IPM/CS group, and none was serious., Conclusions: The clinical efficacy of DRPM in treating moderate or severe biliary tract infection requiring drainage was comparable to that of IPM/CS. DRPM was associated with no serious adverse events and a low incidence of adverse events. The results of this trial demonstrate that DRPM is a useful therapeutic option for moderate or severe biliary tract infection.

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)., (Copyright © 2014 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

Objectives: A consensus exists among clinicians that imipenem/cilastatin is the most epileptogenic carbapenem, despite inconsistencies in the literature., Methods: We conducted a meta-analysis of all randomized controlled trials comparing carbapenems with each other or with non-carbapenem antibiotics to assess the risk of seizures for imipenem, meropenem, ertapenem and doripenem., Results: In the risk difference (RD) analysis, there were increased patients with seizure (2 per 1000 persons, 95% CI 0.001, 0.004) among recipients of carbapenems versus non-carbapenem antibiotics. This difference was largely attributed to imipenem as its use was associated with an additional 4 patients per 1000 with seizure (95% CI 0.002, 0.007) compared with non-carbapenem antibiotics, whereas none of the other carbapenems was associated with increased seizure. Similarly, in the pooled OR analysis, carbapenems were associated with a significant increase in the risk of seizures relative to non-carbapenem comparator antibiotics (OR 1.87, 95% CI 1.35, 2.59). The ORs for risk of seizures from imipenem, meropenem, ertapenem and doripenem compared with other antibiotics were 3.50 (95% CI 2.23, 5.49), 1.04 (95% CI 0.61, 1.77), 1.32 (95% CI 0.22, 7.74) and 0.44 (95% CI 0.13, 1.53), respectively. In studies directly comparing imipenem and meropenem, there was no difference in epileptogenicity in either RD or pooled OR analyses., Conclusions: The absolute risk of seizures with carbapenems was low, albeit higher than with non-carbapenem antibiotics. Although imipenem was more epileptogenic than non-carbapenem antibiotics, there was no statistically significant difference in the imipenem versus meropenem head-to-head comparison., (© The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

Objective: We sought to evaluate the safety of imipenem and meropenem in the treatment of infections in neurosurgical patients., Methods: An observational retrospective study was conducted of consecutive cases treated with imipenem from Sept. 2007 to Sept. 2009 and meropenem within 1 year from Sept. 2008 in Beijing Tiantan Hospital, China. Data including the dosage and duration of the drug use, occurrence of seizures and mortality outcome was collected from the electronic pharmacy records. The incidence of epilepsy, epileptic standardized morbidity rate (SMR) were reported. Attention was paid to the relationship between the use of imipenem/meropenem and the incidence of epilepsy., Results: The imipenem patients within two years amounted to 71, with mean age 45.9±20.2 years, male to female ratio 46/25. The incidence of epilepsy was 11.3% (8 cases). Among them, 1 case occurred during treatment (1/633, 1.6/1000 patient-days), and the remaining 7 cases occurred before treatment (7/2819, 2.5/1000 patient-days), with the standardized incidence rate 0.64, 95% CI (0.08-5.18).The meropenem patients within one year amounted to 92, mean age 45.1±19.4 years, male to female ratio 51/41. The incidence of epilepsy was 6.5% (6 cases). 2 occurred during treatment (2/582, 2.0/1000 patients-hospital days) and 4 before treatment (4/2047, 3.4/1000 patients-inpatient days), standardized incidence rate 1.76, 95% CI (0.32-9.63)., Conclusion: Despite many other epileptogenic factors, imipenem or meropenem did not increase the risk of seizures in neurosurgical patients. There was not further risk for patients with pre-existing seizures or creatinine clearance abnormalities when dosed appropriate.

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.

In a previous phase 3 study, the cure rates that occurred in patients with hospital-acquired pneumonia treated with tigecycline at the approved dose were lower than those seen with patients treated with imipenem and cilastatin (imipenem/cilastatin). We hypothesized that a higher dose of tigecycline is necessary in patients with hospital-acquired pneumonia. This phase 2 study compared the safety and efficacy of two higher doses of tigecycline with imipenem/cilastatin in subjects with hospital-acquired pneumonia. Subjects with hospital-acquired pneumonia were randomized to receive one of two doses of tigecycline (150 mg followed by 75 mg every 12 h or 200 mg followed by 100 mg every 12 h) or 1 g of imipenem/cilastatin every 8 h. Empirical adjunctive therapy was administered for initial coverage of methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa infection, depending on the randomization regimen. Clinical response, defined as cure, failure of treatment, or indeterminate outcome, was assessed 10 to 21 days after the last day of therapy. In the clinically evaluable population, clinical cure with tigecycline 100 mg (17/20, 85.0%) was numerically higher than with tigecycline 75 mg (16/23, 69.6%) and imipenem/cilastatin (18/24, 75.0%). No new safety signals with the high-dose tigecycline were identified. A numerically higher clinical response was observed with the 100-mg dose of tigecycline. This supports our hypothesis that a higher area under the concentration-time curve over 24 h in the steady state divided by the MIC (AUC/MIC ratio) may be necessary to achieve clinical cure in patients with hospital-acquired pneumonia. Further studies are necessary. (The ClinicalTrials.gov identifier for this clinical trial is NCT00707239.).

Objectives: The aim of this prospective phase II, randomized, investigator-blinded study (NCT00690378) was to compare the efficacy and safety of ceftazidime-avibactam and imipenem-cilastatin in hospitalized adults with serious complicated urinary tract infection (cUTI) due to Gram-negative pathogens., Patients and Methods: Patients aged between 18 and 90 years with cUTI were enrolled and stratified by infection type (acute pyelonephritis or other cUTI) and randomized 1:1 to receive intravenous ceftazidime 500 mg plus avibactam 125 mg every 8 hours or imipenem-cilastatin 500 mg every 6 hours. Patients meeting pre-specified improvement criteria after 4 days could be switched to oral ciprofloxacin. Patients were treated for a total of 7-14 days. The primary efficacy objective was a favorable microbiological response at the test-of-cure (TOC) visit 5-9 days post-therapy in microbiologically evaluable (ME) patients., Results: Overall, 135 patients received study therapy (safety population); 62 were included in the ME population (ceftazidime-avibactam, n = 27; imipenem-cilastatin, n = 35). The predominant uropathogen was Escherichia coli. Favorable microbiological response was achieved in 70.4% of ME patients receiving ceftazidime-avibactam and 71.4% receiving imipenem-cilastatin at the TOC visit (observed difference -1.1% [95% CI: -27.2%, 25.0%]). Among ME patients with ceftazidime-resistant uropathogens, response was observed in 6/7 (85.7%) receiving ceftazidime-avibactam. Adverse events were observed in 67.6% and 76.1% of patients receiving ceftazidime-avibactam and imipenem-cilastatin, respectively. Limitations of the study include the small number of patients in the ME population., Conclusion: The results suggest that the efficacy and safety of ceftazidime-avibactam may be similar to that of imipenem-cilastatin.

Objective: To evaluate the efficacy and safety of domestic imipenem cilastatin sodium for the treatments of severe aspiration pneumonia., Methods: A randomize, open, parallel-controlled trial was conducted. Sixty-eight patients with severe aspiration pneumonia were divided into trial group (n=36) and control group (n=32) by random distribution method. The application of trial group domestic imipenem cilastatin sodium was 1.0 g intravenous drip, every 6-8 hours for 7-14 days. The control group application with imported injection imipenem cilastatin sodium was 1.0 g intravenous drip, every 6-8 hours for 7-14 days. The highest daily temperature (T), heart rate (HR), breathing rate (RR), pulse blood oxygen saturation (SpO(2)), blood oxygen partial pressure (PaO(2)), inhaled oxygen concentration (FiO(2)), oxygenation index (PaO(2)/FiO(2)), airway peak pressure (Paw), minute ventilation (MV) and white blood count (WBC), pro calcitonin (PCT), high-sensitivity C-reactive protein (hs-CRP) index before and 1, 3, 7 days after treatment, and liver and kidney function, chest X-rays, and sputum cultures of drug sensitive test were conducted. And the effectiveness and safety were determined according to the standards., Results: After treatment indexes of the two groups were obviously improved, i. e. T, HR, RR, Paw, MV, the WBC, PCT, CRP were gradually declined, PaO(2)/FiO(2) was gradually raised. There were statistical significance before and 3 days after treatment in the trial and the control group [T: 37.35±0.91 centigrade vs. 38.43±1.06 centigrade, 37.28±0.88 centigrade vs. 38.35±1.11 centigrade; HR: 90.25±10.60 bpm vs. 118.94±15.46 bpm, 89.31±11.17 bpm vs. 124.34±17.87 bpm; RR: 25.14±3.17 bpm vs. 32.28±4.49 bpm, 24.81±2.43 bpm vs. 33.13±4.17 bpm; Paw: 23.03±3.04 cm H(2)O vs. 33.22±4.59 cm H(2)O, 22.75±3.22 cm H(2)O vs. 33.63±4.79 cm H(2)O; MV: 8.67±1.26 L/min vs. 11.80±2.01 L/min, 8.88±1.45 L/min vs. 13.21±2.90 L/min; WBC: 11.26±1.96 ×10(9)/L vs. 14.57±3.10 ×10(9)/L, 12.28±3.38 ×10(9)/L vs. 15.25±4.93 ×10(9)/L; PCT: 6.90±5.46 μg/L vs. 16.97±7.93 μg/L, 6.17±6.13 μg/L vs. 21.26±11.54 μg/L; CRP: 85.50±37.91 mg/L vs. 120.17±45.47 mg/L, 94.31±38.51 mg/L vs. 142.34±53.57 mg/L; PaO(2)/ FiO(2): 182.06±40.88 mm Hg vs. 98.67±20.62 mm Hg, 184.09±43.78 mm Hg vs. 96.22±22.59 mm Hg, all P<0.05]. There was no significant change in SpO(2) before and after treatment in two groups. And the total clinical effective rate in trial and control group were 83.4% and 81.2%, adverse reaction rate were 13.9% and 9.4%, bacterial removal rate were 90.3% and 87.0% respectively, and there was no significant difference between the two groups (all P>0.05)., Conclusion: Domestic imipenem cilastatin sodium can effectively control severe aspiration pneumonia, and it is safe and effective antibiotics.

To compare efficacy and safety of a tigecycline regimen with an imipenem/cilastatin regimen in hospital-acquired pneumonia patients, a phase 3, multicenter, randomized, double-blind, study evaluated 945 patients. Coprimary end points were clinical response in clinically evaluable (CE) and clinical modified intent-to-treat (c-mITT) populations at test-of-cure. Cure rates were 67.9% for tigecycline and 78.2% for imipenem (CE patients) and 62.7% and 67.6% (c-mITT patients), respectively. A statistical interaction occurred between ventilator-associated pneumonia (VAP) and non-VAP subgroups, with significantly lower cure rates in tigecycline VAP patients compared to imipenem; in non-VAP patients, tigecycline was noninferior to imipenem. Overall mortality did not differ between the tigecycline (14.1%) and imipenem regimens (12.2%), although more deaths occurred in VAP patients treated with tigecycline than imipenem. Overall, the tigecycline regimen was noninferior to the imipenem/cilastatin regimen for the c-mITT but not the CE population; this difference appears to have been driven by results in VAP patients., (Copyright © 2010. Published by Elsevier Inc.)

In this prospective, randomized, open-label clinical trial, we compared the efficacy and safety of two antibiotic regimens for severe diabetic foot infections (DFI). Sixty-two in-patients with DFI received either piperacillin/tazobactam (Pip-Tazo, n = 30) (4.5 g intravenously every 8h) or imipenem/cilastatin (IMP, n = 32) (0.5 g intravenously every 6h). The mean duration of treatment was 21 days for Pip-Tazo and 24 days for IMP. Twenty-two (73.3%) patients in the Pip-Tazo group and 26 (81.2%) patients in the IMP group had DFI associated with osteomyelitis. Successful clinical response was seen in 14 (46.7%) patients in the Pip-Tazo group and in nine (28.1%) patients in the IMP group [relative risk (RR) 1.6 (95% CI 0.84-3.25), p 0.130]. Two patients in the IMP group and none in the PIP-Tazo group relapsed [RR 2 (0.94-4.24), p 0.058]. Eighty-nine microorganisms were isolated: 38 (43%) Gram-positive and 51(57%) Gram-negative. Among patients with positive culture, 47 (96%) had complete and two (4%) had partial microbiological response. Microbiological response rates were similar in both groups (p 1.000). Amputation was performed in 18 (60%) and 22 (69%) patients in the Pip-Tazo and IMP groups (p 0.739) respectively. Side effects were more common in the Pip-Tazo group (30% vs. 9.4%), but they were generally mild and reversible. In conclusion, although the sample size was small and the results did not reach statistical significance, Pip-Tazo produced a better clinical response rate than IMP in the treatment of severe DFI. There was no significant difference between the treatment groups with respect to microbiological response, relapse and amputation rates.

Background: Tigecycline, a first-in-class broad-spectrum glycylcycline antibiotic, has broad-spectrum in vitro activity against bacteria commonly encountered in complicated intra-abdominal infections (cIAIs), including aerobic and facultative Gram-positive and Gram-negative bacteria and anaerobic bacteria. In the current trial, tigecycline was evaluated for safety and efficacy vs. imipenem/cilastatin in hospitalized Chinese patients with cIAIs., Methods: In this phase 3, multicenter, open-label study, patients were randomly assigned to receive IV tigecycline or imipenem/cilastatin for /=1 dose of study drug and comprised the modified intent-to-treat population. In the microbiologically evaluable population, 86.5% (45 of 52) of tigecycline- and 97.9% (47 of 48) of imipenem/cilastatin-treated patients were cured at the test-of-cure assessment (12-37 days after therapy); in the microbiologic modified intent-to-treat population, cure rates were 81.7% (49 of 60) and 90.9% (50 of 55), respectively. The overall incidence of treatment-emergent adverse events was 80.4% for tigecycline vs. 53.9% after imipenem/cilastatin therapy (P < 0.001), primarily due to gastrointestinal-related events, especially nausea (21.6% vs. 3.9%; P < 0.001) and vomiting (12.4% vs. 2.0%; P = 0.005)., Conclusions: Clinical cure rates for tigecycline were consistent with those found in global cIAI studies. The overall safety profile was also consistent with that observed in global studies of tigecycline for treatment of cIAI, as well as that observed in analyses of Chinese patients in those studies; no novel trends were observed., Trial Registration: ClinicalTrials.gov NCT00136201.

Background: Biapenem is an injectable carbapenem antibiotic. A clinical study was designed to evaluate its efficacy and safety in the treatment of respiratory and urinary infections compared to imipenem/cilastatin., Methods: A total of 216 patients with respiratory or urinary tract infections were enrolled into this multicenter, open-label, randomized controlled clinical study. Each patient was randomly assigned to either the treatment or control group; 106 patients in each group were included in the ITT analyses. The patients were given biapenem 300 mg or imipenem/cilastatin 500 mg/500 mg two or three times daily, i.v. g.t.t. for 7-14 days according to their conditions., Results: The cure and effective rates were 67.92 and 88.68% in the biapenem group and 76.02 and 93.40% in the imipenem/cilastatin group, the bacterial eradication rates were 93.83 and 98.82%, and the adverse-event rates were 6.54 and 7.41%, respectively. There were no significant differences between the two groups (p > 0.05)., Conclusion: Biapenem is as effective and well-tolerated as imipenem/cilastatin for the treatment of intermediate and severe bacterial infections., (Copyright © 2010 S. Karger AG, Basel.)

Background: Several generic imipenem/cilastatin formulations have been approved by Thai FDA and a generic imipenem/cilastatin (Yungjin) has been available in SirirajHospital since 2007. Since imipenem/cilastatin is usually given to the patients with serious hospital-acquired infections, the generic imipenem/cilastatin must be therapeutically equivalent to the original imipenem/cilastatin. The objective of the study was to compare effectiveness and safety of generic imipenem/cilastatin with original imipenem/cilastatin for therapy of infections in hospitalized patients at Siriraj Hospital., Material and Method: Medical records of adult hospitalized patients at Siriraj Hospital who received imipenem/cilastatin at least 48 hours during June 2007 to September 2008 were reviewed. The effectiveness data of 300 patients who received original imipenem/cilastatin were compared with those of 300 patients who received generic imipenem/cilastatin in order to determine if a difference in composite favorable outcome of both formulations was within 10%., Results: The demographics, clinical features of infections, site of infections, type of causative organisms and concomitant antibiotics of the patients in both groups were not significantly different. The overall favorable outcomes in the original imipenem/cilastatin and the generic imipenem/cilastatin groups were 65% and 58.7% respectively (absolute difference 6.3%, 95% CI -1.4% to 14%). Cure rates of infections in the original imipenem/cilastatin and the generic imipenem/cilastatin groups were 35% and 28.7% respectively (absolute difference 6.3%, 95% CI -1.1% to 13.7%). Super-infection rates in the original imipenem/cilastatin and the generic imipenem/cilastatin groups were 4.7% and 9% respectively (absolute difference -4.3%, 95% CI -8.5% to 0.3%). Mortality due to infections in the original imipenem/cilastatin and the generic imipenem/cilastatin groups were 18.3% and 21.3% respectively (absolute difference -3%, 95% CI -9.4% to 3.4%). Overall mortality in the original imipenem/cilastatin and the generic imipenem/cilastatin groups were 35.3% and 43% respectively (absolute difference -7.7%, 95% CI -15.3% to 0.1%). The occurrence of adverse events in the patients in both groups was not significantly different., Conclusion: Although the point estimate of composite favorable outcome of the patients who received generic imipenem/cilastatin (Yungjin) was < 10% of those who received original imipenem/cilastatin (Tienam), generic imipenem/cilastatin showed a trend for therapeutic non-equivalence to original imipenem/cilastatin because the upper limits of 95% confidence interval of differences of several important clinical outcomes were more than 10%.

Background: Administration of imipenem-cilastatin to patients with IgE-mediated hypersensitivity to beta-lactams has always been considered potentially harmful. Recent studies have demonstrated the tolerability of carbapenems (imipenem-cilastatin and meropenem) in patients with IgE-mediated hypersensitivity to beta-lactams; there are no studies on this topic regarding patients with cell-mediated allergy to beta-lactams. The aim of this study is to assess cross-reactivity and tolerability of imipenem in patients with cell-mediated allergy to beta-lactams., Methods: From our database we selected 73 patients with cell-mediated allergy to beta-lactams, diagnosed by means of immediate-type skin tests, delayed reading intradermal tests, patch tests and detection of specific IgE. Patients with negative patch tests with imipenem-cilastatin underwent an intramuscular test dosing., Results: Our patients had a total of 94 nonimmediate reactions to penicillins. All patients had positive patch tests and/or delayed reading intradermal tests for at least one of the penicillin reagent tested and negative immediate-type skin tests and specific IgE. Four patients out of 73 had a positive patch tests to at least one penicillin reagent and imipenem-cilastatin showing cross-reactivity. Sixty-four patients underwent the imipenem-cilastatin intramuscular test dosing and none of them had a clinical reaction., Conclusions: Our rate of cross-reactivity between imipenem-cilastatin and other beta-lactams was 5.5%. This result is different from previous findings and this may be explained by the fact that we investigated patients with cell-mediated allergy to beta-lactams. Patients with cell-mediated allergy to beta-lactams should undergo patch tests and a tolerance challenge test before treatment with imipenem-cilastatin.

Tebipenem pivoxil (TBPM-PI), the first oral carbapenem antibiotic both in Japan and abroad, was examined on its convulsive liability. We used ICR male mice and Sprague-Dawley male rats to examine the pro-convulsive effect and anticonvulsive effect of TBPM-PI and its active metabolite, TBPM. (1) When mice were treated with TBPM-PI (30-1000 mg/kg, p.o.) or TBPM (10-300 mg/kg, i.v.), no convulsion was noted at any dose level. When rats were treated with TBPM (300 mg/kg, i.v.), no convulsant effects were noted in electroencephalography or behavioral observation. In intraventricular injection of TBPM in mice, clonic convulsion was observed in 7/10 animals at 100 microg but no effect at 30 microg. On the other hand, the administration of 10/10 microg imipenem/cilastatin (IPM/CS) resulted in clonic convulsion in all animals and tonic convulsion in 3/10 animals, and 4/10 animals died. The administration of 100 microg meropenem did not cause any effects. (2) When mice were co-administered with pentylenetetrazole (45 mg/kg: maximum dose level at which no convulsion is induced) and TBPM-PI (30-300 mg/kg, p.o.) or TBPM (300 mg/kg, i.v.), convulsion enhancing effect was not noted. On the other hand, the co-administration of pentylenetetrazole with IPM/CS (300/300 mg/kg, i.v.) enhanced a convulsive effect of pentylenetetrazole. (3) When mice were treated with TBPM-PI (30-300 mg/kg, p.o.) or TBPM (100 mg/kg, i.v.), inhibitory effect was not noted on convulsions induced by electrostimulation, pentylenetetrazole or strychinine. In conclusion, there were no pro-convulsive effects or anticonvulsive effect in the oral administration of TBPM-PI or intravenous administration of TBPM. Pro-convulsive effect was observed in the intraventricular injection of TBPM as in the case of other carbapenem antibiotics, but such action was weaker than that in IPM/CS administration. Accordingly, the risk of occurrence of convulsion related to TBPM-PI administration was low compared to IPM/CS administration, and TBPM-PI was considered to be less potential to induce convulsions in clinical use.

Background and Aims: This study addresses whether antibiotic prophylaxis is beneficial for acute necrotizing pancreatitis., Methods: This randomized, controlled trial enrolled 276 patients with severe acute pancreatitis. There were 56 patients with 30% or more necrosis proved by contrast-enhanced computerized tomography who were eligible for randomization: 29 in the study group and 27 in the control group, who received i.v. imipenem-cilastatin (3 x 500 mg/day) within 72 h of the onset of symptoms for 7-14 days, and no antibiotic prophylaxis, respectively. The primary end-point was the incidence of infectious complication. The secondary end-points were mortality, the incidence of necrosectomy for infected necrosis, the incidence of organ complication and hospital courses., Results: Characteristics of baseline data were similar in the two groups. No significant differences were found in the incidence of infected pancreatic necrosis (37% vs 27.6%), mortality (10.3% vs 14.8%) and the incidence of operative necrosectomy (29.6% vs 34.6%) between the study group and the control group (P > 0.05). The incidence of extrapancreatic infections, organ complications and hospital courses between the groups were also not significantly different. However, a significantly increased incidence of fungal infection was observed in the study group versus the control group (36.1% vs 14.2%, P < 0.05)., Conclusion: There was no benefit in the outcomes when antibiotic prophylaxis was routinely used in patients with acute necrotizing pancreatitis.

A 73-year-old, ASA I patient scheduled for transurethral resection of the prostate under subarachnoid anesthesia received, prior to the beginning of the surgery, intravenous imipenem/cilastatin 1 g for a urinary infection with multiresistant Escherichia coli. The patient developed seizures during the surgical procedure. Central nervous toxicity of imipenem/cilastatin might have been the cause of the seizures. After appropriate management, the patient recovered well and was discharged without complications. The differential diagnosis between systemic toxicity of local anesthetics and imipenem-related seizures is discussed.

Background: Infection in the intensive care unit (ICU) empirically requires broad-spectrum antibiotics. Imipenem/cilastatin, often reserved for more serious hospital-acquired infections, is thought to be associated with a higher risk of seizures than other penicillins and carbapenems. We sought to evaluate the safety of imipenem/cilastatin in the treatment of infections, including meningitis, in neurocritical care patients., Methods: Pertinent literature was identified through MEDLINE (1966-2007) using search terms imipenem, seizure, carbapenem, and meropenem. A review of the literature is presented., Results: Carbapenem antibiotics remain active against most Gram-positive and Gram-negative organisms, and are often used in critically ill patients. Drug-induced seizures are a rare but serious adverse effect, with carbapenems being one of the most common classes of antibiotics associated with seizures. Seizure rates in patients treated with imipenem/cilastatin and meropenem are similar. One small pediatric study of 21 patients showed a high incidence of seizures and is often cited as the reason imipenem should not be used in meningitis. However, many studies noting seizures with both meropenem and imipenem/cilastatin attribute this to patients with lower body weight, elderly, or those with impaired renal function., Conclusions: When dosed appropriately, imipenem/cilastatin may be used to treat serious infections in critically ill patients with central nervous system (CNS) disorders or injury with minimal seizure risk. Imipenem/cilastatin safety data is lacking for meningitis and cautious use is warranted.

CW-270031 is a novel synthesized carbapenem antibiotic with a broad antimicrobial activity. Carbapenem antibiotics are well known for their nephrotoxicity. In this study, we evaluated the nephrotoxicity potential of this compound in rabbits, which are known for being more sensitive than other animals to renal insult. CW-270031 was administered to NZW male rabbits via an ear vein (200 mg/kg, single injection). Blood samples were collected on 2, 3, and 4 days after treatment. Urea nitrogen and creatinine in plasma were quantified. Four days after the treatment, all animals were autopsied and histopathological examinations were performed on their kidneys, revealing that cephaloridine and imipenem were highly nephrotoxic, and cefazolin had mild renal toxicity, whereas CW-270031 as well as meropenem and tienam had no toxicity to the kidney. The present findings suggest that CW-270031 is a potential carbapenem antibiotic with no nephrotoxicity.

Strong data are lacking on the cross-reactivity between individual carbapenems. We describe a 48-year-old woman with ventilator-associated Pseudomonas aeruginosa pneumonia who received an 8-day course of imipenem-cilastatin and experienced a delayed (i.e., nonimmediate) hypersensitivity reaction, evidenced by an extensive erythematous macular morbilliform rash and an increased eosinophil count. Eight days after completion of therapy, the pneumonia returned, and it was decided to avoid using imipenem-cilastatin; she was administered a 14-day course of meropenem. To our knowledge, this is the first report of a nonimmediate hypersensitivity reaction to imipenem-cilastatin without cross-reactivity to meropenem. This suggests that if carbapenem therapy is unavoidable, meropenem may be cautiously administered in patients with a known allergy to imipenem-cilastatin.

Imipenem is often used in treatment of acute exacerbations of severe chronic obstructive pulmonary disease (COPD). Superinfection following imipenem therapy is a common cause of treatment failure and high economic burden. This study is aimed to explore any clinical factors which determine the risk of superinfection after imipenem treatment in acute exacerbations of severe COPD. A prospective observational study was conducted in a 5-bed respiratory intensive care unit of a Chinese University hospital. Fifty-one patients with acute exacerbations of severe COPD who were hospitalised and treated with imipenem for more than 3 days were enrolled during 1.5 year. The associations between the risk of superinfection and potential factors were analysed by logistic regression. Forty-seven out of 51 patients (92.2%) had their symptoms and signs improved at the end of imipenem treatment. Superinfections were developed in 12 patients, and the superinfection rate was as high as 30.8% (12 out of 39 patients with definite bacteriologic responses). The frequent superinfecting organisms were Stenotrophomonas maltophilia and Pseudomonas aeruginosa. Among a wide range of potential risk factors, we found that lower blood pH, previous cephalosporines treatment and longer period of imipenem treatment are independently associated with a higher risk of superinfection. The risk of superinfection following imipenem treatment in hospitalised patients with acute exacerbations of COPD was high. Lower blood pH, previous cephalosporines treatment and longer period of imipenem treatment all increased the risk of superinfection.

Background: Piperacillin/tazobactam (P/T) with its broad spectrum of antibacterial activity is used widely for the treatment of moderate to severe polymicrobial nosocomial infections., Patients and Methods: The efficacy and safety of P/T was compared with imipenem/cilastatin (I/C) in patients with established nosocomial pneumonia. This multicentre study took place from January 1999 to December 2001. Due to difficulties in recruiting sufficient patients it was terminated prematurely. In all, 221 patients were randomly assigned to either P/T at 4 g/0.5 g (n = 110) or I/C at 1 g/1 g (n = 111). Additional aminoglycoside therapy was mandatory if Pseudomonas aeruginosa was present. The ITT population (107 P/T and 110 I/C patients) was used for the analysis of efficacy., Results: The clinical efficacy was equally good for the P/T and I/C groups; 71% [95% CI 61.3, 79.2] vs 77.3% [95% CI 68.1, 84.5] at the end of therapy, 66.4% [95% CI 56.5, 75] vs 70% [95% CI 60.4, 78.2] on day 3, a nd 59.8% [95% CI 49.9, 69] vs 66.4% [95% CI 56.6, 74.9] on day 14 after therapy, respectively. Proven or assumed bacterial eradication at the end of therapy was 45.8% (P/T) and 52.7% (I/C). Treatment-related adverse events (AE) were recorded in 30% of P/T patients and 25.2% I/C patients. There were ten serious treatment-related AEs in the P/T group and five in the I/C group., Conclusion: Although numbers were inadequate for full statistical evaluation, P/T and I/C were similarly effective in the treatment of severe nosocomially acquired pneumonia.

Objective: To evaluate the clinical usefulness of sulbactam/ampicillin therapy for community-acquired pneumonia in the elderly., Methodology: A randomized prospective clinical study was conducted in the elderly patients with moderate-to-severe community-acquired bacterial pneumonia., Results: Overall clinical efficacy of sulbactam/ampicillin therapy (6 g/day) in these patients (efficacy rate: 91.4%) was comparable to that of imipenem/cilastatin therapy (1 g/day; efficacy rate: 87.5%), when each therapy was administered intravenously twice daily for 7-14 days. With regard to clinical efficacy based on disease severity, bacteriological efficacy, improvement of chest X-ray findings and adverse reactions, the two therapies were comparable., Conclusion: These results suggest that sulbactam/ampicillin therapy has excellent efficacy and tolerability and that it may be highly effective, even in severe cases of pneumonia. This regimen may thus serve as first-line treatment for the treatment of community-acquired pneumonia in elderly patients.

Background: Complicated intra-abdominal infections (cIAI) remain challenging to treat because of their polymicrobial etiology including multi-drug resistant bacteria. The efficacy and safety of tigecycline, an expanded broad-spectrum glycylcycline antibiotic, was compared with imipenem/cilastatin (IMI/CIS) in patients with cIAI., Methods: A prospective, double-blind, multinational trial was conducted in which patients with cIAI randomly received intravenous (IV) tigecycline (100 mg initial dose, then 50 mg every 12 hours [q12h]) or IV IMI/CIS (500/500 mg q6h or adjusted for renal dysfunction) for 5 to14 days. Clinical response at the test-of-cure (TOC) visit (14-35 days after therapy) for microbiologically evaluable (ME) and microbiological modified intent-to-treat (m-mITT) populations were the co-primary efficacy endpoint populations., Results: A total of 825 patients received >or= 1 dose of study drug. The primary diagnoses for the ME group were complicated appendicitis (59%), and intestinal (8.8%) and gastric/duodenal perforations (4.6%). For the ME group, clinical cure rates at TOC were 80.6% (199/247) for tigecycline versus 82.4% (210/255) for IMI/CIS (95% CI -8.4, 5.1 for non-inferiority tigecycline versus IMI/CIS). Corresponding clinical cure rates within the m-mITT population were 73.5% (227/309) for tigecycline versus 78.2% (244/312) for IMI/CIS (95% CI -11.0, 2.5). Nausea (31.0% tigecycline, 24.8% IMI/CIS [P = 0.052]), vomiting (25.7% tigecycline, 19.4% IMI/CIS [P = 0.037]), and diarrhea (21.3% tigecycline, 18.9% IMI/CIS [P = 0.435]) were the most frequently reported adverse events., Conclusion: This study demonstrates that tigecycline is as efficacious as imipenem/cilastatin in the treatment of patients with cIAI.

Background: Meropenem, a broad-spectrum carbapenem with potent in vitro activity, is postulated to be an effective monotherapy for the treatment of complicated skin and skin structure infections (cSSSI)., Methods: This multicenter, international, double-blind, randomized, prospective study of hospitalized patients with cSSSI evaluated the efficacy, safety, and tolerability of meropenem (500 mg IV q8h) versus imipenem-cilastatin (500 mg IV q8h). The primary efficacy endpoint was clinical outcome at follow-up in the clinically evaluable (CE) and modified intent-to-treat populations (MITT; patients who met eligibility criteria and received at least one dose of study drug). The study aimed to demonstrate non-inferiority (delta of 10%, 95% confidence intervals) in clinical response in the CE population. Clinical responses for all pathogens at follow-up were assessed in the fully evaluable population (CE population with baseline pathogen and follow-up cultures)., Results: In total, 1,076 patients were enrolled. Of these, 692 patients comprised the MITT population (334 and 358 patients randomized to meropenem and imipenem-cilastatin, respectively) and 548 the CE population (261 and 287 patients randomized to meropenem and imipenem-cilastatin, respectively). Cure rates were 86.2% (meropenem) and 82.9% (imipenemcilastatin; 95% CI, -2.8, 9.3) in the CE population and 73.1% (meropenem) and 74.9% (imipenem-cilastatin; 95% CI, -8.4, 4.7) in the MITT population. The frequencies of adverse events and drug-related adverse events were similar between treatment groups., Conclusion: In one of the largest studies conducted to date of hospitalized patients with cSSSI, meropenem, 500 mg IV q8h had comparable safety and efficacy to imipenem-cilastatin, 500 mg IV q8h.

This pooled analysis includes 2 phase 3, double-blind trials designed to evaluate the safety and efficacy of tigecycline, versus that of imipenem-cilastatin, in 1642 adults with complicated intra-abdominal infections. Patients were randomized to receive either tigecycline (initial dose of 100 mg, followed by 50 mg intravenously every 12 h) or imipenem-cilastatin (500/500 mg intravenously every 6 h) for 5-14 days. The primary end point was the clinical response at the test-of-cure visit (12-42 days after therapy) in the co-primary end point microbiologically evaluable and microbiological modified intent-to-treat populations. For the microbiologically evaluable group, clinical cure rates were 86.1% (441/512) for tigecycline, versus 86.2% (442/513) for imipenem-cilastatin (95% confidence interval for the difference, -4.5% to 4.4%; P < .0001 for noninferiority). Clinical cure rates in the microbiological modified intent-to-treat population were 80.2% (506/631) for tigecycline, versus 81.5% (514/631) for imipenem-cilastatin (95% confidence interval for the difference, -5.8% to 3.2%; P < .0001 for noninferiority). Nausea (24.4% tigecycline, 19.0% imipenem-cilastatin [P = .01]), vomiting (19.2% tigecycline, 14.3% imipenem-cilastatin [P = .008]), and diarrhea (13.8% tigecycline, 13.2% imipenem-cilastatin [P = .719]) were the most frequently reported adverse events. This pooled analysis demonstrates that tigecycline was efficacious and well tolerated in the treatment of patients with complicated intra-abdominal infections.

Imipenem (thienamycin formamidine), a broad-spectrum beta-lactam antibiotic, is always used in combination with cilastatin in order to avoid the premature breakdown of imipenem by renal tubular dipeptidase. As this dipeptidase also hydrolyzes the glutathione metabolite cysteinylglycine, the therapeutic association of imipenem and cilastatin might cause an accumulation of the aminothiol cysteinylglycine. We demonstrate here that when patients are treated with imipenem-cilastatin, their plasma levels of cysteinylglycine are significantly and specifically increased, while cysteine levels are decreased and homocysteine levels are unaffected. We conclude that antibiotic treatment using imipenem-cilastatin induces important metabolic changes that should not remain unrecognized.

Antibiotic-induced severe neutropenia and less frequently agranulocytosis has been reported. In most of these cases a relatively normal myelopoiesis is found. We report on the first case of agranulocytosis with histological evidence of pure white cell aplasia associated with imipenem-cilastatin treatment.

Objectives: The purpose of this retrospective study was to ascertain the clinical safety of administering carbapenems, namely imipenem/cilastatin and meropenem, in patients with a history of penicillin allergy compared with administering carbapenems in patients with no reported penicillin allergy. Carbapenems are similar in chemical structure to the penicillins and therefore are associated with a risk for allergic cross-hypersensitivity. Carbapenems are commonly avoided in patients with a reported penicillin allergy on the basis of a potential cross-hypersensitivity with penicillin, however, very few studies have been conducted describing the incidence of cross-hypersensitivity between penicillin and carbapenems., Methods: A retrospective review was conducted in a total of 266 patients who were administered either imipenem/cilastatin or meropenem. The patients were admitted to the Cleveland Clinic Health System--Eastern Region Hospitals during the years 2001 and 2002., Results: Fifteen of the 163 patients (9.2%) with reported penicillin allergy developed a hypersensitivity reaction to meropenem or imipenem/cilastatin whereas 3.9% of the 103 patients without penicillin allergy developed a hypersensitivity reaction to meropenem or imipenem/cilastatin. These results are not statistically significant., Conclusions: Based on this study and other similar studies, the true incidence of cross-hypersensitivity reactions between penicillin and carbapenems may be lower than previously reported. Carbapenem use may be reasonable for penicillin allergic patients if caution is exercised.

The effects of phenytoin (PHT) and phenobarbital (PHB) on EEG activity and behavior was studied in the model of epilepsy induced by intracerebroventricular (i.c.v.) administration of imipenem/cilastatin (Imi/Cil). Under intraperitoneal (i.p.) sodium pentobarbital anesthesia adult male Wistar albino rats were implanted with electrodes and cannulas were placed into the right lateral ventricle. Animals were divided into groups: 1) Imi/Cil (100/100 microg, i.c.v.), 2) PHT (40 mg/kg) + Imi/Cil (100/100 microg, i.c.v), 3) PHT (80 mg/kg) + Imi/Cil (100/100 microg, i.c.v.), 4) PHT (160 mg/kg) + Imi/Cil (100/100 microg, i.c.v.), 5) PHB (50 mg/kg) + Imi/Cil (100/100 microg, i.c.v.), and 6) PHB (80 mg/kg) + Imi/Cil (100/100 microg, i.c.v.). PHT and PHB were injected intraperitoneally (i.p.) 1 h before Imi/Cil. Seizures were scored according to the scale: 0--normal behavior; 1--twitching, 2--head nodding, forelimb clonus, 3--rearing, and 4--clonic-tonic convulsions. Imi/Cil provoked maximal seizures in all animals, and all rats died 10 - 18 min after the injection. Epileptiform activity preceded behavioral seizures. Clonic-tonic seizures were associated with continuous bursts of high-frequency high-amplitude spikes in the EEG. PHT and PHB suppressed Imi/Cil-induced seizures dose-dependently. PHB reduced epileptiform discharges during behavioral seizures elicited by Imi/Cil, while PHT had no effect on EEG epileptic phenomena. These results suggest that PHT acts as anticonvulsant, and PHB as anticonvulsant and antiepileptic agent in the model of epilepsy induced by Imi/Cil.