Treatment Of cIAI Research Articles

Efficacy of tigecycline for the treatment of complicated intra-abdominal infections in real-life clinical practice from five European observational studies

Tigecycline is a broad-spectrum antibiotic approved for the treatment of complicated intra-abdominal infections (cIAIs). The efficacy of tigecycline when administered as monotherapy or in combination with other antibacterials in the treatment of cIAIs in routine clinical practice is described. Individual patient-level data were pooled from five European observational studies (July 2006 to October 2011). A total of 785 cIAI patients who received tigecycline were included (mean age 63.1 ± 14.0 years). Of these, 56.6% were in intensive care units, 65.6% acquired their infection in hospital, 88.1% had at least one comorbidity and 65.7% had secondary peritonitis. The mean Acute Physiology and Chronic Health Evaluation (APACHE) II and Sequential Organ Failure Assessment (SOFA) scores at the beginning of treatment were 16.9 ± 7.6 (n = 614) and 7.0 ± 4.2 (n = 108), respectively, indicating high disease severity. Escherichia coli (41.8%), Enterococcus faecium (40.1%) and Enterococcus faecalis (21.1%) were the most frequently isolated pathogens; 49.1% of infections were polymicrobial and 17.5% were due to resistant pathogens. Overall, 54.8% (n = 430) received tigecycline as monotherapy and 45.2% (n = 355) as combination therapy for a mean duration of 10.6 days. Clinical response rates at the end of treatment were 77.4% for all patients (567/733), 80.6% for patients who received tigecycline as monotherapy (329/408), 75.2% for patients with a nosocomial infection (354/471), 75.8% for patients with an APACHE II score >15 (250/330) and 54.2% (32/59) for patients with a SOFA score ≥ 7. In these real-life studies, tigecycline, alone and in combination, achieved favourable clinical response rates in patients with cIAI with a high severity of illness.

Moxifloxacin is non-inferior to combination therapy with ceftriaxone plus metronidazole in patients with community-origin complicated intra-abdominal infections

Management of community-origin complicated intra-abdominal infections (cIAIs) requires surgical intervention and antimicrobial therapy. This multinational, randomised, double-blind clinical trial carried out in Asia compared the efficacy and safety of moxifloxacin monotherapy and ceftriaxone/metronidazole combination therapy in adults with confirmed or suspected cIAI. Patients received surgical intervention and either intravenous (i.v.) moxifloxacin 400 mg once daily or i.v. ceftriaxone 2 g once daily plus i.v. metronidazole 500 mg twice daily. A total of 364 patients were randomised [intent-to-treat (ITT), moxifloxacin N = 180, comparator N = 181; per-protocol (PP), moxifloxacin N = 174, comparator N = 171]. The most common cIAI diagnosis was complicated appendicitis. Moxifloxacin was non-inferior to ceftriaxone/metronidazole in terms of clinical response at test-of-cure in the PP population [clinical cure, 90.2% for moxifloxacin vs. 96.5% for ceftriaxone/metronidazole; 95% confidence interval (CI) of the difference −11.7 to −1.7] and in the ITT population (87.2% for moxifloxacin vs. 91.2% for ceftriaxone/metronidazole; 95% CI −10.7 to 1.9). Bacteriological cure rates in the microbiologically evaluable population support the clinical results (89.4% for moxifloxacin vs. 95.9% for ceftriaxone/metronidazole; 95% CI −13.3 to −0.6). The incidence of treatment-emergent adverse events was similar for both treatment groups (moxifloxacin 31.7% vs. comparator 24.3%). These results confirm previous findings that moxifloxacin plus adequate source control is an appropriate treatment of cIAI.

Moxifloxacin for the Treatment of Patients with Complicated Intra-abdominal Infections (the AIDA Study)

This prospective, randomized, open, international, multicenter study of adults with complicated intra-abdominal infections (cIAI) compared the efficacy and safety of sequential intravenous (i.v.) to oral (p.o.) moxifloxacin 400 mg once daily, with that of i.v. ceftriaxone 2 g once daily, plus metronidazole 500 mg three times daily, followed by p.o. amoxicillin/clavulanate 625 mg three times daily. The primary efficacy variable was clinical cure at test of cure (TOC) (day 28-42 after study entry) in the per protocol (PP) population. Of 595 patients in the study, 511 patients were valid for PP analysis (246 moxifloxacin, 265 ceftriaxone/metronidazole). Sequential moxifloxacin was noninferior to the comparator regimen - clinical cure rates at TOC were 80.9% ver-sus 82.3% (moxifloxacin versus ceftriaxone/metronidazole; 95% CI -8.9, 4.2%). The incidence of adverse events was comparable between the two treatment groups. Therefore, sequential moxifloxacin monotherapy is as effective and safe as combination therapy with i.v. ceftriaxone plus i.v. metronidazole followed by oral amoxicillin/clavulanate for the treatment of cIAI.

Doripenem monohydrate, a broad-spectrum carbapenem antibiotic

Background: Doripenem monohydrate, a broad-spectrum carbapenem antibiotic, has been approved by the US Food and Drug Administration for the treatment of complicated intra-abdominal infections (cIAIs) and complicated urinary tract infections (cUTIs). Objective: This article reviews available information on doripenem in the management of patients with complicated bacterial infections, including its chemistry, spectrum of activity, resistance mechanisms, pharmacokinetics, pharmacodynamics, drug interactions, therapeutic efficacy, tolerability, and dosing and administration. Also discussed are pharmacoeconomic considerations associated with doripenem. Methods: Pertinent English-language literature was identified from searches of MEDLINE (1996–October 2008) and BIOSIS (1993–October 2008). Search terms included, but were not limited to, doripenem, S-4661, spectrum of activity, resistance, pharmacology, pharmacokinetics, pharmacodynamics, adverse events, and therapeutic use. Additional publications were found by searching the reference lists of identified articles and reviewing abstracts from meetings of the Interscience Conference on Antimicrobial Agents and Chemotherapy (2003–2007). Results: Doripenem is a parenteral carbapenem antibiotic with in vitro activity against gram-positive, gram-negative, and anaerobic organisms. It is stable against a wide variety of β-lactamases, including extended-spectrum and AmpC β-lactamases; it is, however, inactivated by organisms that produce class A enzymes, KPC enzymes, class B metallo-β-lactamases, and class D enzymes. Doripenem is eliminated primarily in the urine (68%–80% unchanged). It should be used cautiously in patients receiving valproic acid, as combined use may lead to a precipitous decline in serum concentrations of valproic acid. A large Phase III study in the treatment of cIAIs found doripenem noninferior to meropenem (clinical cure rates, 83.9% and 85.9%, respectively; difference, −2.1; 95% CI, −9.8 to 5.6). A Phase III study in the treatment of cIAIs, including pyelonephritis, found doripenem non-inferior to levofloxacin (clinical cure rates, 95.1% and 90.2%, respectively; 95% CI, 0.2 to 9.6). With respect to the treatment of nosocomial pneumonia, one Phase III study found doripenem noninferior to imipenem (clinical cure rates, 68.3% and 64.8%, respectively; difference, 3.5%; 95% CI, −9.1 to 16.1), and another found it noninferior to piperacillin/tazobactam (clinical cure rates, 81.3% and 79.8%, respectively; difference, 1.5%; 95% CI, −9.1 to 12.1). Adverse events with doripenem were similar to those of other antibiotics with which it has been compared. Adverse events in clinical trials of doripenem have included anaphylaxis and rash (l%-5%), gastrointestinal effects (25%–32%, including nausea [1.1%–12.0%], diarrhea [1.9%–11.0%], and vomiting [1.5%-6.6%]), and central nervous system effects (headache [2.1%–16.0%], insomnia [3.7%], anxiety [2.9%], and, rarely, seizures). Conclusions: In Phase III studies, doripenem was noninferior to meropenem in the treatment of cIAIs; noninferior to levofloxacin in the treatment of cUTIs; and noninferior to imipenem and piperacillin/tazobactam in the treatment of nosocomial pneumonia. As with all new antibiotics, because of the risk of selecting for resistant organisms, use of doripenem should be reserved for infections in which a multidrug-resistant gram-negative organism, polymicrobial infection, or Pseudomonas aeruginosa is suspected.

Efficacy and tolerability of IV doripenem versus meropenem in adults with complicated intra-abdominal infection: A phase III, prospective, multicenter, randomized, double-blind, noninferiority study

Background: Complicated intra-abdominal infections (cIAIs) require surgical intervention and empiric antibacterial therapy. Doripenem, a broad-spectrum carbapenem, provides coverage of key gram-negative and -positive aerobes and anaerobes encountered in cIAI. Objective: This study was designed to compare the efficacy and safety profile of doripenem and meropenem in hospitalized adult patients with cIAI. Methods: In this prospective, multicenter, doubleblind, noninferiority study, hospitalized adults with cIAI were randomly assigned to receive doripenem 500 mg IV q8h or meropenem 1 g IV q8h. After a minimum of 9 doses and adequate clinical improvement (relative to before the start of IV study drug, decreased body temperature and white blood cell count, improved or absent signs and symptoms of cIAI, and return of normal bowel function), patients could be switched to oral amoxicillin/clavulanate. Antibacterial therapy (IV plus subsequent oral) was given for a total of 5 to 14 days. The coprimary efficacy end points were the clinical cure rate (complete resolution or significant improvement of signs or symptoms of the index infection) in patients microbiologically evaluable (≥1 baseline pathogen isolated from an intra-abdominal culture that was susceptible to both IV study drug therapies) at the test-of-cure (TOC) visit (21-60 days after the completion of study drug therapy) and the clinical cure rate in the microbiological modified intent-to-treat (mMITT) population (a bacterial pathogen identified at baseline, regardless of its susceptibility to the study drug). Noninferiority was concluded if the lower limit of the 2-sided 95% CI for the difference (doripenem minus meropenem) in the proportion of patients classified as clinical cures was ≥-15%. Results: A total of 476 patients were enrolled. The microbiologically evaluable population (319 patients) was 62.7% male and 67.7% white, with a mean age and weight of 46.7 years and 77.2 kg, respectively. In this population, doripenem and meropenem were associated with clinical cure rates at the TOC visit of 85.9% and 85.3%, respectively. The corresponding treatment difference was 0.6% (95% CI, -7.7% to 9.0%); this difference was not statistically significant. Similarly, in the mMITT population (385 patients), the clinical cure rates were 77.9% and 78.9%, respectively, and the corresponding 1.0% treatment difference was not statistically significant (95% CI, -9.7% to 7.7%). Clinical cure rates were not significantly different between the 2 treatment arms in key subgroups (eg, age, sex, race, baseline Acute Physiology and Chronic Health Evaluation II score, primary infection site). Microbiological eradication rates for common pathogens isolated at study entry were not significantly different between the 2 treatment groups. Doripenem was well tolerated in the population studied. In the intent-to-treat population (471 patients), 83.0% and 78.0% of patients experienced ≥1 adverse event (AE) and 13.2% and 14.0% experienced ≥1 serious AE in the doripenem and meropenem treatment arms, respectively. In the doripenem and meropenem treatment arms, AEs resulted in study drug discontinuation in 5.1% and 2.1% of patients and death in 2.1% and 3.0% of patients, respectively. Conclusions: The present study found that doripenem (500 mg q8h) was effective in the treatment of cIAI, was therapeutically noninferior to meropenem (1 g q8h), with a safety profile not significantly different from that of meropenem in this selected population of patients with cIAI.