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Antimicrobial Agents and Chemotherapy Nov 2011In this review, we summarize the current "state of the art" of carbapenem antibiotics and their role in our antimicrobial armamentarium. Among the β-lactams currently... (Review)
Review
In this review, we summarize the current "state of the art" of carbapenem antibiotics and their role in our antimicrobial armamentarium. Among the β-lactams currently available, carbapenems are unique because they are relatively resistant to hydrolysis by most β-lactamases, in some cases act as "slow substrates" or inhibitors of β-lactamases, and still target penicillin binding proteins. This "value-added feature" of inhibiting β-lactamases serves as a major rationale for expansion of this class of β-lactams. We describe the initial discovery and development of the carbapenem family of β-lactams. Of the early carbapenems evaluated, thienamycin demonstrated the greatest antimicrobial activity and became the parent compound for all subsequent carbapenems. To date, more than 80 compounds with mostly improved antimicrobial properties, compared to those of thienamycin, are described in the literature. We also highlight important features of the carbapenems that are presently in clinical use: imipenem-cilastatin, meropenem, ertapenem, doripenem, panipenem-betamipron, and biapenem. In closing, we emphasize some major challenges and urge the medicinal chemist to continue development of these versatile and potent compounds, as they have served us well for more than 3 decades.
Topics: Anti-Bacterial Agents; Carbapenems; Cilastatin; Cilastatin, Imipenem Drug Combination; Doripenem; Drug Combinations; Ertapenem; Humans; Imipenem; Thienamycins; beta-Alanine; beta-Lactams
PubMed: 21859938
DOI: 10.1128/AAC.00296-11 -
Clinical Infectious Diseases : An... Dec 2021Imipenem combined with the β-lactamase inhibitor relebactam has broad antibacterial activity, including against carbapenem-resistant gram-negative pathogens. We... (Randomized Controlled Trial)
Randomized Controlled Trial
A Randomized, Double-blind, Multicenter Trial Comparing Efficacy and Safety of Imipenem/Cilastatin/Relebactam Versus Piperacillin/Tazobactam in Adults With Hospital-acquired or Ventilator-associated Bacterial Pneumonia (RESTORE-IMI 2 Study).
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.
Topics: Adult; Aged; Anti-Bacterial Agents; Azabicyclo Compounds; Cilastatin; Hospitals; Humans; Imipenem; Piperacillin; Tazobactam; Ventilators, Mechanical
PubMed: 32785589
DOI: 10.1093/cid/ciaa803 -
Clinical Infectious Diseases : An... Apr 2020The β-lactamase inhibitor relebactam can restore imipenem activity against imipenem-nonsusceptible gram-negative pathogens. We evaluated imipenem/relebactam for... (Randomized Controlled Trial)
Randomized Controlled Trial
RESTORE-IMI 1: A Multicenter, Randomized, Double-blind Trial Comparing Efficacy and Safety of Imipenem/Relebactam vs Colistin Plus Imipenem in Patients With Imipenem-nonsusceptible Bacterial Infections.
BACKGROUND
The β-lactamase inhibitor relebactam can restore imipenem activity against imipenem-nonsusceptible gram-negative pathogens. We evaluated imipenem/relebactam for treating imipenem-nonsusceptible infections.
METHODS
Randomized, controlled, double-blind, phase 3 trial. Hospitalized patients with hospital-acquired/ventilator-associated pneumonia, complicated intraabdominal infection, or complicated urinary tract infection caused by imipenem-nonsusceptible (but colistin- and imipenem/relebactam-susceptible) pathogens were randomized 2:1 to 5-21 days imipenem/relebactam or colistin+imipenem. Primary endpoint: favorable overall response (defined by relevant endpoints for each infection type) in the modified microbiologic intent-to-treat (mMITT) population (qualifying baseline pathogen and ≥1 dose study treatment). Secondary endpoints: clinical response, all-cause mortality, and treatment-emergent nephrotoxicity. Safety analyses included patients with ≥1 dose study treatment.
RESULTS
Thirty-one patients received imipenem/relebactam and 16 colistin+imipenem. Among mITT patients (n = 21 imipenem/relebactam, n = 10 colistin+imipenem), 29% had Acute Physiology and Chronic Health Evaluation II scores >15, 23% had creatinine clearance <60 mL/min, and 35% were aged ≥65 years. Qualifying baseline pathogens: Pseudomonas aeruginosa (77%), Klebsiella spp. (16%), other Enterobacteriaceae (6%). Favorable overall response was observed in 71% imipenem/relebactam and 70% colistin+imipenem patients (90% confidence interval [CI] for difference, -27.5, 21.4), day 28 favorable clinical response in 71% and 40% (90% CI, 1.3, 51.5), and 28-day mortality in 10% and 30% (90% CI, -46.4, 6.7), respectively. Serious adverse events (AEs) occurred in 10% of imipenem/relebactam and 31% of colistin+imipenem patients, drug-related AEs in 16% and 31% (no drug-related deaths), and treatment-emergent nephrotoxicity in 10% and 56% (P = .002), respectively.
CONCLUSIONS
Imipenem/relebactam is an efficacious and well-tolerated treatment option for carbapenem-nonsusceptible infections.
CLINICAL TRIALS REGISTRATION
NCT02452047.
Topics: Anti-Bacterial Agents; Azabicyclo Compounds; Bacterial Infections; Colistin; Humans; Imipenem; Microbial Sensitivity Tests
PubMed: 31400759
DOI: 10.1093/cid/ciz530 -
Clinical Microbiology and Infection :... Jan 2008Among the many different structurally distinct classes of beta-lactams, the carbapenem class is regarded as that which is most potent and which has the widest spectrum... (Review)
Review
Among the many different structurally distinct classes of beta-lactams, the carbapenem class is regarded as that which is most potent and which has the widest spectrum of antimicrobial activity. Rapidly bactericidal, and demonstrating time-dependent killing, carbapenemes have a spectrum of antimicrobial activity that includes Gram-positive and Gram-negative aerobic and anaerobic pathogens. Their in-vitro activity includes extended-spectrum beta-lactamase (ESBL)-producing pathogens and carbapenems are currently considered to be the treatment of choice for serious infections due to ESBL-producing organisms. However, isolates acquiring resistance under treatment have been reported. Imipenem, meropenem and ertapenem are licensed in the European Community and panipenem and biapenem are also available in Japan and South Korea. Other carbapenemes are under development.
Topics: Anti-Bacterial Agents; Carbapenems; Ertapenem; Gram-Negative Bacteria; Gram-Negative Bacterial Infections; Gram-Positive Bacteria; Humans; Imipenem; Infusions, Parenteral; Meropenem; Thienamycins; beta-Lactam Resistance; beta-Lactamases; beta-Lactams
PubMed: 18154543
DOI: 10.1111/j.1469-0691.2007.01868.x -
Drugs Feb 2021Imipenem/cilastatin/relebactam (Recarbrio™) is an intravenously administered combination of the carbapenem imipenem, the renal dehydropeptidase-I inhibitor cilastatin,... (Review)
Review
Imipenem/cilastatin/relebactam (Recarbrio™) is an intravenously administered combination of the carbapenem imipenem, the renal dehydropeptidase-I inhibitor cilastatin, and the novel β-lactamase inhibitor relebactam. Relebactam is a potent inhibitor of class A and class C β-lactamases, conferring imipenem activity against many imipenem-nonsusceptible strains. Imipenem/cilastatin/relebactam is approved in the USA and EU for the treatment of hospital-acquired bacterial pneumonia (HABP) and ventilator-associated bacterial pneumonia (VABP) in adults and other gram-negative infections, including complicated urinary tract infections (cUTIs) [including pyelonephritis] and complicated intra-abdominal infections (cIAIs), in adults with limited or no alternative treatment options. In pivotal phase II and III trials, imipenem/cilastatin/relebactam was noninferior to piperacillin/tazobactam in patients with HABP/VABP and to imipenem/cilastatin in patients with cUTIs and cIAIs. It was also effective in imipenem-nonsusceptible infections. Imipenem/cilastatin/relebactam was generally well tolerated, with a safety profile consistent with that of imipenem/cilastatin. Available evidence indicates that imipenem/cilastatin/relebactam is an effective and generally well tolerated option for gram-negative infections in adults, including critically ill and/or high-risk patients, and a potential therapy for infections caused by carbapenem-resistant pathogens.
Topics: Anti-Bacterial Agents; Azabicyclo Compounds; Cilastatin; Drug Combinations; Gram-Negative Bacterial Infections; Humans; Imipenem; Injections, Intravenous; beta-Lactamase Inhibitors; beta-Lactamases
PubMed: 33630278
DOI: 10.1007/s40265-021-01471-8 -
BMC Microbiology Nov 2022Enterobacter cloacae complex (ECC) is a common opportunistic pathogen and is responsible for causing various infections in humans. Owing to its inducible chromosomal...
BACKGROUND
Enterobacter cloacae complex (ECC) is a common opportunistic pathogen and is responsible for causing various infections in humans. Owing to its inducible chromosomal AmpC β-lactamase (AmpC), ECC is inherently resistant to the 1st- and 2nd- generation cephalosporins. However, whether β-lactams antibiotics enhance ECC resistance remains unclear.
RESULTS
In this study, we found that subinhibitory concentrations (SICs) of cefazolin (CFZ) and imipenem (IMP) can advance the expression of AmpC and enhance its resistance towards β-lactams through NagZ in Enterobacter cloacae (EC). Further, AmpC manifested a substantial upregulation in EC in response to SICs of CFZ and IMP. In nagZ knockout EC (ΔnagZ), the resistance to β-lactam antibiotics was rather weakened and the effect of CFZ and IMP on AmpC induction was completely abrogated. NagZ ectopic expression can rescue the induction effects of CFZ and IMP on AmpC and increase ΔnagZ resistance. More importantly, CFZ and IMP have the potential to induce the expression of AmpR's target genes in a NagZ-dependent manner.
CONCLUSIONS
Our findings suggest that NagZ is a critical determinant for CFZ and IMP to promote AmpC expression and resistance and that CFZ and IMP should be used with caution since they may aggravate ECC resistance. At the same time, this study further improves our understanding of resistance mechanisms in ECC.
Topics: Humans; Anti-Bacterial Agents; Cefazolin; Enterobacter cloacae; Imipenem; Monobactams
PubMed: 36443681
DOI: 10.1186/s12866-022-02707-7 -
Revista Espanola de Quimioterapia :... Apr 2022Imipenem combined with beta-lactamase inhibitor relebactam (IMI/REL) has an extensive bactericidal activity against Gram-negative pathogens producing class A or class C... (Review)
Review
Imipenem combined with beta-lactamase inhibitor relebactam (IMI/REL) has an extensive bactericidal activity against Gram-negative pathogens producing class A or class C beta-lactamases, not active against class B and class D. The phase 3 clinical trial (RESTORE-IMI-2), double-blind, randomized, evaluated IMI/REL vs. piperacillin-tazobactam (PIP/TAZ) for treatment of hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP), demonstrated non-inferiority at all-cause mortality at 28 days (15.9% vs 21.3%), favorable clinical response at 7-14 days end of treatment (61% vs 59.8%) and with minor serious adverse effects (26.7% vs 32%). IMI/REL is a therapeutic option in HAP and VAP at approved dosage imipenem 500 mg, cilastatin 500 mg and relebactam 250 mg once every 6h, by an IV infusion over 30 min.
Topics: Anti-Bacterial Agents; Azabicyclo Compounds; Cilastatin; Clinical Trials, Phase III as Topic; Drug Therapy, Combination; Humans; Imipenem; Patient Acuity; Pneumonia, Ventilator-Associated; Randomized Controlled Trials as Topic
PubMed: 35488826
DOI: 10.37201/req/s01.11.2022 -
Antimicrobial Agents and Chemotherapy Jul 2022Imipenem (IMI)/cilastatin/relebactam (REL) (I/R) is a novel β-lactam/β-lactamase inhibitor combination with expanded microbiologic activity against... (Review)
Review
Imipenem (IMI)/cilastatin/relebactam (REL) (I/R) is a novel β-lactam/β-lactamase inhibitor combination with expanded microbiologic activity against carbapenem-resistant non- (CR-NME) and difficult-to-treat (DTR) Pseudomonas aeruginosa. Relebactam, a bicyclic diazabicyclooctane, has no direct antimicrobial activity but provides reliable inhibition of many Ambler class A and class C enzymes. It is currently approved for the treatment of adult patients with hospital-acquired bacterial pneumonia and ventilator-associated bacterial pneumonia (HABP/VABP) and those with complicated urinary tract infections (cUTIs) and complicated intra-abdominal infections (cIAIs) when limited or no alternative treatments are available. Given the number of recently approved β-lactams with expanded activity against highly resistant Gram-negative pathogens, this review summarizes the published literature on I/R, with a focus on its similar and distinguishing characteristics relative to those of other recently approved agents. Overall, available data support its use for the treatment of patients with HABP/VABP, cUTI, and cIAI due to CR-NME and DTR P. aeruginosa. Data indicate that I/R retains some activity against CR-NME and DTR P. aeruginosa isolates that are resistant to the newer β-lactams and vice versa, suggesting that susceptibility testing be performed for all the newer agents to determine optimal treatment options for patients with CR-NME and DTR P. aeruginosa infections. Further comparative PK/PD and clinical studies are warranted to determine the optimal role of I/R, alone and in combination, for the treatment of patients with highly resistant Gram-negative infections. Until further data are available, I/R is a potential treatment for patients with CR-NME and DTR P. aeruginosa infections when the benefits outweigh the risks.
Topics: Adult; Anti-Bacterial Agents; Azabicyclo Compounds; Carbapenems; Humans; Imipenem; Microbial Sensitivity Tests; Pneumonia, Bacterial; Pseudomonas aeruginosa; beta-Lactamase Inhibitors
PubMed: 35727059
DOI: 10.1128/aac.00256-22 -
Diagnostic Microbiology and Infectious... Jun 2023A total of 35,360 Enterobacterales isolates were consecutively collected from 75 US medical centers in 2018-2022. Among these isolates, 2612 (7.4%) were categorized as...
Ceftazidime-avibactam, meropenem-vaborbactam, and imipenem-relebactam activities against multidrug-resistant Enterobacterales from United States Medical Centers (2018-2022).
A total of 35,360 Enterobacterales isolates were consecutively collected from 75 US medical centers in 2018-2022. Among these isolates, 2612 (7.4%) were categorized as multidrug-resistant (MDR). Isolates were susceptibility tested by reference broth microdilution methods. Carbapenem-resistant Enterobacterales (CRE) were screened for carbapenemase (CPE) genes by whole genome sequencing. The highest MDR rates was observed among Klebsiella pneumoniae (12.2%), followed by Raoultella spp. (10.9%) and Providencia stuartii (9.8%). Ceftazidime-avibactam and meropenem-vaborbactam were very active and showed identical susceptibility rates against MDR isolates (97.9%). Imipenem-relebactam (93.5% susceptible [S]) exhibited slightly lower susceptibility rates due to its limited activity against Morganellaceae family. The most active β-lactamase inhibitor combination (BLI) against CRE isolates (n = 310) was ceftazidime-avibactam (84.2%S), followed by meropenem-vaborbactam (81.9%S) and imipenem-relebactam (74.8%S). All 3 BLIs were very active against KPC producers and none were active against MBL producers. Ceftazidime-avibactam exhibited greater activity against OXA-48-type producers than meropenem-vaborbactam and imipenem-vaborbactam.
Topics: United States; Humans; Meropenem; Anti-Bacterial Agents; Ceftazidime; Azabicyclo Compounds; Drug Combinations; Imipenem; beta-Lactamases; Carbapenems; Microbial Sensitivity Tests
PubMed: 37060707
DOI: 10.1016/j.diagmicrobio.2023.115945 -
International Journal of Antimicrobial... Oct 2023Mycobacterium abscessus is an emerging infection in people living with lung diseases, including cystic fibrosis (CF) and bronchiectasis, and it has limited treatment...
OBJECTIVES
Mycobacterium abscessus is an emerging infection in people living with lung diseases, including cystic fibrosis (CF) and bronchiectasis, and it has limited treatment options and low cure rates. The off-label use of novel antibiotics developed for other bacterial pathogens offers potential new therapeutic options. We aimed to describe the in vitro activity of imipenem, imipenem-relebactam and tedizolid against comparator antibiotics in M. abscessus isolates from Australian patients with and without CF.
METHODS
We performed susceptibility testing for imipenem-relebactam, tedizolid and comparator antibiotics by Clinical and Laboratory Standards Institute (CLSI) criteria against 102 clinical M. abscessus isolates, including 46 from people with CF.
RESULTS
In this study, the minimum inhibitory concentration (MICs) of imipenem-relebactam was one-fold dilution less than of imipenem alone. The MIC and MIC of imipenem-relebactam were 8 and 16 mg/L, respectively, whereas for imipenem they were 16 and 32 mg/L. Tedizolid had an MIC and MIC of 2 and 4 mg/L, respectively. Forty non-CF isolates had linezolid susceptibility performed, with MIC and MIC values of 16 and 32 mg/L, respectively, measured.
CONCLUSIONS
This study shows lower MICs for imipenem-relebactam and tedizolid compared to other more commonly used antibiotics and supports their consideration in clinical trials for M. abscessus treatment.
Topics: Humans; Mycobacterium abscessus; Australia; Anti-Bacterial Agents; Imipenem; Microbial Sensitivity Tests
PubMed: 37517624
DOI: 10.1016/j.ijantimicag.2023.106938