***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Although metronidazole ( MNZ ) has been used worldwide for more than 4 decades as a st and ard therapy for trichomoniasis , anaerobic and amebic infections , resistance to MNZ is still low . MNZ is available as oral , intravenous , and vaginal formulations , but the intravenous formulation of MNZ has not been approved in Japan . We conducted a phase 3 study to evaluate the efficacy and safety of intravenous MNZ combined with ceftriaxone ( CTRX ) in Japanese subjects with infectious peritonitis , abdominal abscess or pelvic inflammatory diseases ( PIDs ) to obtain regulatory approval . A combination of MNZ/CTRX at doses of 500 mg 3 or 4 times a day/1 or 2 g twice a day was administered intravenously to a total of 38 hospitalized subjects .  MNZ/CTRX was well tolerated and exhibited excellent clinical and bacteriological efficacy with clinical efficacy rates of 100 % ( 20/20 ) in infectious peritonitis or abdominal abscess subjects and 90.0 % ( 9/10 ) in PID subjects , and the eradication rates in infectious peritonitis or abdominal abscess subjects and PID subjects were 100 % ( 16/16 ) and 100 % ( 4/4 ) , respectively , at the test of cure . MNZ/CTRX was effective in 1 subject in whom a metallo-β-lactamase-producing Bacteroides fragilis strain ( MIC of MNZ , 2 μg/ml ) was identified . The most common treatment-related adverse event was diarrhea ( 23.7 % ) , followed by nausea ( 5.3 % ) . No new safety signals were identified . MNZ/CTRX  demonstrated excellent efficacy and was well tolerated in Japanese infectious peritonitis , abdominal abscess and PID subjects . This treatment regimen can be useful for anaerobic infections . Clinical registration number : NCT01473836 Tigecycline ( TGC ) has demonstrated clinical efficacy and safety , in comparison with imipenem/cilastatin in phase 3 clinical trials , for complicated intra-abdominal infection ( cIAI ) . The present study comprised a multicentre , open-label , r and omized study of TGC vs. ceftriaxone plus metronidazole ( CTX/MET ) for the treatment of patients with cIAI . Eligible subjects were r and omized ( 1:1 ) to receive either an initial dose of TGC  ( 100 mg ) followed by 50 mg every 12 h or CTX ( 2 g once daily ) plus MET ( 1 - 2 g daily ) , for 4 - 14 days . The primary endpoint was the clinical response in the clinical ly evaluable ( CE ) population at the test of cure ( TOC ) assessment . Of 473 r and omized subjects , 376 were CE . Among these , clinical cure rates were 70.4 % ( 133/189 ) with TGC vs. 74.3 % ( 139/187 ) with CTX/MET ( 95 % CI -13.1 to 5.1 ; p 0.009 for non-inferiority ) . Clinical cure rates for subjects with Acute Physiological and Chronic Health Evaluation II scores > or = 10 were 56.8 % ( 21/37 ) with TGC vs. 58.3 % ( 21/36 ) with CTX/MET . The microbiologic response was similar between the two treatment arms , with microbiological eradication at TOC achieved in 68.1 % ( 94/138 ) of TGC-treated subjects and 71.5 % ( 98/137 ) of CTX/MET-treated subjects . ( The most frequently reported adverse events ( AEs ) for both treatment arms were nausea ( TGC , 38.6 % vs CTX/MET , 27.7 % ) and vomiting ( TGC , 23.3 % vs CTX/MET , 17.7 % ) . Overall discontinuation rates as a result of an AE were 8.9 % and 4.8 % in TGC- and comparator-treated subjects , respectively . The results obtained in the present study demonstrate that TGC monotherapy is non-inferior to a combination regimen of CTX/MET with respect to treating subjects with cIAI BACKGROUND Appropriate antimicrobial therapy results in improved clinical outcomes in complicated intra-abdominal infections ( cIAIs ) . Recent in vitro studies have reported increasing moxifloxacin resistance of Bacteroides species , thereby caution ing empiric use in infections with these organisms . METHODS This pooled analysis of 4 r and omized clinical trials ( 2000 - 2010 ) evaluated the comparative efficacy of  moxifloxacin  in cIAIs , including infection with anaerobic organisms . The intent-to-treat population included 1209 patients who received moxifloxacin ( 745 microbiologically valid cases ) and 1193 patients who received comparator agents ( 741 microbiologically valid cases ) . RESULTS Overall clinical success rates in the per- protocol population were 85.6 % ( 817 of 955 patients ) for moxifloxacin and 87.8 % ( 860 of 979 patients ) for comparators . Of 642 pretherapy anaerobes from moxifloxacin-treated  patients , 561 ( 87.4 % ) were susceptible at ≤2 mg/L , 34 ( 5.3 % ) were intermediate at 4 mg/L , and 47 ( 7.3 % ) were resistant at ≥8 mg/L. Moxifloxacin achieved similar clinical success rates against all anaerobes including those isolated from patients infected with Bacteroides fragilis ( 158 [ 82.7 % ] of 191 patients ) , Bacteroides thetaiotaomicron ( 74 [ 82.2 % ] of 90 patients ) and Clostridium species ( 37 [ 80.4 % ] of 46 patients ) . The overall clinical success rate for all anaerobes was 82.3 % . For all anaerobes combined , the clinical success rate was 83.1 % ( 466 of 561 patients ) for a minimum inhibitory concentration ( MIC ) of ≤2 mg/L , 91.2 % ( 31 of 34 patients ) for an MIC of 4 mg/L , 82.4 % ( 14 of 17 patients ) for an MIC of 8 mg/L , 83.3 % ( 5 of 6 patients ) for an MIC of 16 mg/L , and 66.7 % ( 16 of 24 patients ) for an MIC of ≥32 mg/L. CONCLUSIONS Moxifloxacin demonstrated clinical success for intra-abdominal infections caused by both aerobic and anaerobic isolates . More than 87 % of baseline anaerobic isolates from intra-abdominal infections were susceptible to moxifloxacin , and efficacy was maintained beyond the current susceptibility breakpoint MIC of ≤2 mg/L against major anaerobes Summary In an open , r and omised , multicentre trial , the efficacy and tolerability of empirical meropenem monotherapy ( 1 g intravenously every 8 hours ) and cefotaxime ( 2 g every 8 hours ) plus metronidazole ( 0.5 g intravenously every 8 hours ) for 5 to 10 days was compared in 94 patients with serious intra-abdominal infection who required surgery . Eighty-three patients had an evaluable clinical response .  Significantly more patients in the meropenem group had a satisfactory clinical response at the end of treatment ( 41/43 [ 95.3 % ] vs 30/40 [ 75.0 % ] ; p=0.008 ) . The bacteriological response was also higher in the meropenem group ( 31/33 vs 26/32 ) . In the bacteriologically evaluable population , a satisfactory clinical response was observed in 31/33 of those who received meropenem compared to 24/32 of the cefotaxime/metronidazole recipients ( p=0.03 ) . Empirical meropenem monotherapy should prove a useful alternative to the currently st and ard combination treatment for serious intraabdominal infections . ZusammenfassungIn einer offenen , r and omisierten Multicenter-Studie wurden die Wirksamkeit und Verträglichkeit einer initialen Monotherapie mit Meropenem ( MEM , 1 g 3 × tägl . i.v . ) mit der etablierten Kombinationstherapie Cefotaxim ( CTX ) plus Metronidazol ( MTR ) ( 2 g CTX+0.5 g MTR 3 × tägl . i.v . ) verglichen . 94 Patienten mit operationspflichtigen schweren intraabdominellen Infektionen wurden einbezogen . Davon waren 83 Patienten bezüglich klinischem Ansprechen auswertbar . Die klinische Wirksamkeit war in der MEM-Gruppe signifikant höher ( 41/43 Pat.=95.3 % vs 30/40 Pat.=75 % ; p=0.008 ) . Das bakteriologische Ansprechen war in der MEM-Gruppe ebenfalls höher i m Vergleich zur Kombinationsgruppe ( 31/33 vs 26/32 ) , der Unterschied war jedoch statistisch nicht signifikant . In der bakteriologisch auswertbaren Population war das klinische Ansprechen in der MEM-Gruppe signifikant höher als i m Vergleichskollektiv ( 31/33 vs 24/32 ; p=0.03 ) . MEM erscheint somit für die initiale empirische Monotherapie bei schweren intraabdominellen Infektionen geeignet OBJECTIVES Avibactam , a novel non-β-lactam β-lactamase inhibitor , restores the in vitro activity of ceftazidime against class A , C and some class D β-lactamase-producing pathogens , including those commonly associated with complicated intra-abdominal infections ( cIAIs ) . This r and omized , active-controlled , double-blind , Phase II trial ( NCT00752219 ) aim ed to evaluate the safety and efficacy of ceftazidime/avibactam plus metronidazole compared with meropenem in hospitalized patients with cIAI . METHODS Adults with confirmed cIAI requiring surgical intervention and antibiotics were r and omized 1 : 1 to receive intravenously either ( i ) 2000 mg of ceftazidime plus 500 mg of avibactam plus a separate infusion of 500 mg of metronidazole or ( ii ) 1000 mg of meropenem plus placebo every 8 h for a minimum of 5 days and a maximum of 14 days . The primary efficacy endpoint was the clinical response in microbiologically evaluable ( ME ) patients at the test-of-cure ( TOC ) visit 2 weeks after the last dose of study therapy . RESULTS Overall , 101 patients received ceftazidime/avibactam plus metronidazole ; 102 received meropenem . The median duration of treatment was 6.0 and 6.5 days , respectively . Favourable clinical response at the TOC visit in the ME population was observed in 91.2 % ( 62/68 ) and 93.4 % ( 71/76 ) of patients in the ceftazidime/avibactam plus metronidazole and meropenem groups , respectively ( observed difference : -2.2 % ; 95 % CI : -20.4 % , 12.2 % ) . The incidence of treatment-emergent adverse events was similar for ceftazidime/avibactam plus metronidazole ( 64.4 % ) and meropenem ( 57.8 % ) . CONCLUSIONS Ceftazidime/avibactam plus metronidazole was effective and generally well tolerated in patients with cIAI , with a favourable clinical response rate in the ME population of > 90 % , similar to that of meropenem In a r and omized , double-blind clinical trial conducted at 13 medical centers , meropenem ( 1,000 mg given iv every 8 hours ) was compared with the combination of clindamycin ( 900 mg every 8 hours ) plus tobramycin ( 5 mg/[kg.d ] in three divided doses ) given iv for the treatment of intra-abdominal infections that required surgery and parenteral antibiotic therapy . At the end of treatment ,  efficacy data  on patients who met study inclusion criteria ( intent-to-treat ) were available for 132 of 215 patients in the meropenem group and 134 of 212 patients in the clindamycin/tobramycin group ; 120 ( 91 % ) of 132 intent-to-treat patients in the meropenem group were cured , 115 ( 86 % ) of 134 intent-to-treat patients in the clindamycin/tobramycin group were cured ( P value , not significant ) . Of the patients treated with mer 
    Output:
    
Combined therapy with metronidazole is as effective and safe as carbapenem in treatment of cIAI .
Therefore , combined therapy with metronidazole offers an effective alternative to carbapenem with low risk of drug resistance