Safety and outcomes in patients receiving arbekacin or vancomycin 

Safety and outcomes in patients receiving arbekacin or vancomycin 

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Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of ear infections. We attempted to evaluate the clinical usefulness of arbekacin in treating chronic suppurative otitis media (CSOM) by comparing its clinical efficacy and toxicity with those of vancomycin. Efficacy was classified according to bacterial elimination or bacteriologic...

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... during the medication period were more com- mon in the vancomycin group (33.3%, 12/36) than in the arbeka- cin group (5.0%, 1/20) (P = 0.020). In addition, a total of 12 ad- verse reactions were found, including two instances of hepato- toxicity, one of nephrotoxicity, eight leukopenia, two skin rash- es, and one case of drug fever in the vancomycin group (Table 4). Only one patient was treated with alternative antibiotics be- cause of an adverse reaction in the vancomycin group. ...
Context 2
... BE of the arbekacin and vancomycin groups were 85.0% and 97.2%, respectively (Table 4). The BE of the arbekacin group was 12.2% lower than that of the vancomycin group, but this was not statistically significant (P = 0.125). ...

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Staphylococcus aureus (SA) and Pseudomonas aeruginosa (PA) are known to cause biofilm-related infections. MRSA and PA have been frequently isolated from chronically infected wounds, cystic fibrosis, chronic suppurative otitis media (CSOM), and from indwelling medical devices, and these bacteria co-exist; however, their interaction with each-other o...

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... While, in the current study, the main species detected were P. aeruginosa and Klebsiella not MRSA. Levofloxacin allows single dosing regimen, which is much easier for patients especially for a long period with lower mistake chances as levofloxacin has long clearance half-life [20]. Levofloxacin 500 mg shows mild adverse reaction during the study period, which occurs in elderly patients only. ...
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Objective To evaluate levofloxacin efficiency in treatment of CSOM of sample of Iraqi patients. Patients and method This is a prospective study include 50 patients of different age group diagnosed with CSOM. Local aural toilet, then otosporin drops applied topically in clinic and each visit, after that levofloxacin prescribed as single oral daily dose for four to six weeks. Patients examined every two weeks for 8weeks then once by month for six months to evaluate the efficiency of treatment. Results 40 patients (80%) show complete dryness and healing. Discharge decreased up on visit with more dryness observed after four weeks of treatment. Signs of healing and tympanic perforation closure apparently occur about one month from initial treatment in 32 patients (80% of successful treatment). Culture sensitivity tests results were Pseudomonas Aerogenosa and , Klebsiella species in discharge materials. Conclusion levofloxacin is safe and effective drug for treatment of CSOM and promising treatment for CSOM in combination with aural toilet. The main species of microorganism detected were pseudomonas aerogenosa and, Klebsiella
... These results were very similar to our previous arbekacin/vancomycin studies which showed that arbekacin had similar bacteriological and clinical efficacy and excellence in safety in comparison to vancomycin for treating patients with MRSA infection. 5,10 Although BER and CER were not significantly different between the two groups (arbekacin vs. teicoplanin), we nevertheless observed fewer adverse reactions in the arbekacin group than in the teicoplanin group. These results suggest that arbekacin is a good alternative drug to teicoplanin or vancomycin for treatment of MRSA infection. ...
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Complications during the medication period were more commonly recorded in the teicoplanin group (36.6%, 26/71) than in the arbekacin group (18.3%, 13/71) (p=0.003) (Table 1). The BER of the arbekacin and teicoplanin groups were 72.9% (51/70) and 70.3% (45/64), respectively: The BER of the arbekacin group was 2.6% higher than that of the teicoplanin group, but this difference was not significant (p=0.835). The CER of the arbekacin group (59.4%, 41/69) was lower than that of the teicoplanin group (69.1%, 47/68), however, this difference was not statistically significant (p=0.257). These results were very similar to our previous arbekacin/vancomycin studies which showed that arbekacin had similar bacteriological and clinical efficacy and excellence in safety in comparison to vancomycin for treating patients with MRSA infection.5, 10
... In another interesting study, arbekacin was used to treat chronic suppurative otitis media (CSOM) caused by MRSA [34]. In that study, 95 patients were diagnosed with MRSA-infected CSOM. ...
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Arbekacin is a broad-spectrum aminoglycoside used to treat methicillin-resistant Staphylococcus aureus (MRSA). Arbekacin has antibacterial activities against high-level gentamicin-resistant Enterococci, multidrug-resistant Pseudomonas aeruginosa, and Acinetobacter baumannii et al. Here, we reviewed in vitro data on arbekacin in Staphylococci and Gram-negative microorganisms. We also reviewed clinical studies for clinical efficacy and microbiologic efficacy data in patients with identified MRSA and suspected MRSA infections. The overall clinical efficacy ranged from 66.7% to 89.7%. The microbiologic efficacy rate ranged from 46.2% to 83%. In comparative studies between arbekacin and glycopeptides, arbekacin was similar to other glycopeptides with respect to clinical and microbiological efficacy rates. Combination trials with other antibiotics suggest that arbekacin will be a promising strategy to control Enterococcus spp. multi-drug resistant P. aeruginosa. The major adverse reaction was nephrotoxicity/hepatotoxicity, but patients recovered from most adverse reactions without any severe complications. Based on these results, arbekacin could be a good alternative to vancomycin/teicoplanin in MRSA treatment. Finally, therapeutic drug monitoring is recommended to maximize clinical efficacy and decrease nephrotoxicity.
... Arbekacin (ABK) is a unique aminoglycoside with concentration-dependent bactericidal activity and prolonged post-antibiotic effects against MRSA, but it has been commercially available only in several Asian countries. Although more than 2 decades of experience has shown its efficacy in MRSA infections, ABK has not yet been evaluated in cancer patients, including those with hematological malignancies [11][12][13][14][15]. Whereas no benefit has been shown for combination therapy with aminoglycosides and β-lactams as the initial antibiotic regimen for fever in neutropenic patients with cancer [16,17], ABK has the potential to cover drug-resistant gram-positive bacteria, as well as drug-resistant gram-negative bacteria, with synergistic effects when accompanied by various β-lactams [18,19]. ...
... To date, the clinical efficacy of ABK for MRSA infection has been reported as having a roughly 65-95 % success rate, primarily in Japan and Korea, where ABK has been widely distributed [11][12][13][14][15]. However, the efficacy of ABK in proven MRSA infections in patients with hematological malignancies was not sufficiently evaluated in this study and thus remains uncertain. ...
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We performed a clinical trial to investigate the efficacy and safety of arbekacin (ABK), a unique aminoglycoside with activity against methicillin-resistant Staphylococcus aureus (MRSA), in patients with hematological malignancies complicated by high-risk infections. ABK was administered intravenously at a dose of approximately 5 mg/kg with various broad-spectrum β-lactams, followed by therapeutic drug monitoring (TDM). A total of 54 febrile or infectious episodes were registered, and TDM was performed in 44 (81 %) cases. The absolute neutrophil count was below 500/μl in 49 (91 %) cases, and cytotoxic chemotherapy was being administered in 47 (87 %) cases. Before initiation of ABK, 52 (96 %) patients had received fluoroquinolones (n = 37) and/or broad-spectrum β-lactams (n = 34). There were 10 cases of documented infections including one of MRSA pneumonia, and 44 cases of febrile neutropenia. The efficacy at the end of treatment was 80 % for all patients, and efficacy was significantly higher in patients attaining maximum concentrations ≥16 µg/ml or receiving TDM-guided dose-adjustment of ABK (n = 19, 95 vs. 71 %, P = 0.039). Renal toxicity was observed in six cases (11 %) but was generally acceptable. This study demonstrated that TDM-guided ABK administration may be applicable under limited conditions for patients with hematological malignancies.
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Background: Vancomycin is a glycopeptide antibiotic with a high risk of acute liver injury. Resveratrol is believed to protect the liver against toxicity. Aim: To investigate the ability of resveratrol to attenuate vancomycin-induced liver toxicity in rats injected with vancomycin. Method: Twenty-four adult male Wistar rats were distributed into three groups. The control group received only a vehicle, while the treated group received either vancomycin 200 (mg/kg, i. p.) only or vancomycin (200 mg/kg, i. p.) with resveratrol (20 mg/kg, oral gavage). All groups received their dose once daily for 7 days. Hepatic damage was assessed by measuring biochemical parameter levels in serum, aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH). Also, antioxidants and inflammation biomarkers such as Interleukin-6 (IL-6), malondialdehyde (MDA), nitric oxide (NO), and glutathione (GSH) were measured. Furthermore, the vancomycin-induced pathological changes in the liver were evaluated by histopathological studies. Results: In the vancomycin-treated group, hepatic serum biomarkers such as AST, ALT, ALP, IL-6, and MDA were elevated, while NO and GSH were depleted. However, resveratrol co-treatment with vancomycin prevented the elevation of AST, ALT, ALP, IL-6, and MDA and it protected the liver from NO and GSH depletion. Also, regarding vancomycin-induced degeneration of hepatocytes, resveratrol co-treatment with vancomycin prevented such degeneration and improved mononuclear cells in the liver. Conclusion: The results showed that oral administration of resveratrol has a significant hepatoprotective effect against vancomycin-induced hepatotoxicity.
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Background: Chronic suppurative otitis media (CSOM), sometimes referred to as chronic otitis media (COM), is a chronic inflammation and often polymicrobial infection (involving more than one micro-organism) of the middle ear and mastoid cavity, characterised by ear discharge (otorrhoea) through a perforated tympanic membrane. The predominant symptoms of CSOM are ear discharge and hearing loss. Antibiotics are the most common treatment for CSOM, which act to kill or inhibit the growth of micro-organisms that may be responsible for the infection. Antibiotics can be administered both topically and systemically, and can be used alone or in addition to other treatments for CSOM such as ear cleaning (aural toileting). Objectives: To assess the effects of topical versus systemic antibiotics for people with CSOM. Search methods: The Cochrane ENT Information Specialist searched the Cochrane ENT Register; Central Register of Controlled Trials (CENTRAL via the Cochrane Register of Studies); Ovid MEDLINE; Ovid Embase; CINAHL; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the search was 16 March 2020. Selection criteria: We included randomised controlled trials (RCTs) with at least a one-week follow-up involving patients (adults and children) who had chronic ear discharge of unknown cause or CSOM, where the ear discharge had continued for more than two weeks. The studies compared topical antibiotics against systemic (oral, injection) antibiotics. We separated studies according to whether they compared the same type of antibiotic in both treatment groups, or different types of antibiotics. For each comparison we considered whether there was background treatment for both treatment groups, for example aural toileting (ear cleaning). Data collection and analysis: We used the standard Cochrane methodological procedures. We used GRADE to assess the certainty of the evidence for each outcome. Our primary outcomes were: resolution of ear discharge or 'dry ear' (whether otoscopically confirmed or not, measured at between one week and up to two weeks, two weeks up to four weeks, and after four weeks), health-related quality of life using a validated instrument, ear pain (otalgia) or discomfort or local irritation. Secondary outcomes included hearing, serious complications and ototoxicity measured in several ways. Main results: Six studies (445 participants), all with high risk of bias, were included. All but two studies included patients with confirmed CSOM, where perforation of the ear drum was clearly documented. None of the studies reported results for resolution of ear discharge after four weeks or health-related quality of life. 1. Topical versus systemic administration of the same type of antibiotics (quinolones) Four studies (325 participants) compared topical versus systemic (oral) administration of ciprofloxacin. Three studies reported resolution of ear discharge at one to two weeks and found that the topical administration may slightly increase resolution (risk ratio (RR) 1.48, 95% confidence interval (CI) 1.24 to 1.76; 285 participants; 3 studies; I2 = 0%; low-certainty evidence). In these studies, aural toileting was either not mentioned, or limited to the first visit. Three studies (265 participants) reported that they did not suspect ototoxicity in any participants, but it is unclear how this was measured (very low-certainty evidence). No studies reported the outcomes of ear pain or serious complications. No studies reported results for hearing, despite it being measured in three studies. 2. Topical versus systemic administration of different types of antibiotics (quinolones versus aminoglycosides) One study (60 participants) compared topical ciprofloxacin versus gentamicin injected intramuscularly. No aural toileting was reported. Resolution of ear discharge was not measured at one to two weeks. The study did not report any 'side effects' from which we assumed that no ear pain, suspected ototoxicity or serious complications occurred (very low-certainty evidence). The study stated that "no worsening of the audiometric function related to local or parenteral therapy was observed". 3. Topical versus systemic administration of different types of antibiotics (quinolones versus amoxicillin-clavulanic acid) One study compared topical ofloxacin with amoxicillin-clavulanic acid with all participants receiving suction ear cleaning at the first visit. It is uncertain if there is a difference between the two groups in resolution of ear discharge at one to two weeks due to study limitations and the very small sample size (RR 2.93, 95% CI 1.50 to 5.72; 56 participants; very low-certainty evidence). It is unclear if there is a difference between topical quinolone compared with oral amoxicillin-clavulanic acid with regards to ear pain, hearing or suspected ototoxicity (very low-certainty evidence). No studies reported the outcome of serious complications. Authors' conclusions: There was a limited amount of low-quality evidence available, from studies completed over 15 years ago, to examine whether topical or systemic antibiotics are more effective in achieving resolution of ear discharge for people with CSOM. However, amongst this uncertainty there is some evidence to suggest that the topical administration of antibiotics may be more effective than systemic administration of antibiotics in achieving resolution of ear discharge (dry ear). There is limited evidence available regarding different types of antibiotics. It is not possible to determine with any certainty whether or not topical quinolones are better or worse than systemic aminoglycosides. These two groups of compounds have different adverse effect profiles, but there is insufficient evidence from the included studies to make any comment about these. In general, adverse effects were poorly reported.
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Background: Chronic suppurative otitis media (CSOM) is a chronic inflammation and infection of the middle ear and mastoid cavity, characterised by ear discharge (otorrhoea) through a perforated tympanic membrane. The predominant symptoms of CSOM are ear discharge and hearing loss. Systemic antibiotics are a commonly used treatment option for CSOM, which act to kill or inhibit the growth of micro-organisms that may be responsible for the infection. Antibiotics can be used alone or in addition to other treatments for CSOM. Objectives: To assess the effects of systemic antibiotics for people with CSOM. Search methods: The Cochrane ENT Information Specialist searched the Cochrane ENT Register; Central Register of Controlled Trials (CENTRAL via the Cochrane Register of Studies); Ovid MEDLINE; Ovid Embase; CINAHL; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the search was 16 March 2020. Selection criteria: We included randomised controlled trials comparing systemic antibiotics (oral, injection) against placebo/no treatment or other systemic antibiotics with at least a one-week follow-up period, involving patients with chronic (at least two weeks) ear discharge of unknown cause or due to CSOM. Other treatments were allowed if both treatment and control arms also received it. Data collection and analysis: We used the standard Cochrane methodological procedures. We used GRADE to assess the certainty of the evidence for each outcome. Our primary outcomes were: resolution of ear discharge or 'dry ear' (whether otoscopically confirmed or not, measured at between one week and up to two weeks, two weeks to up to four weeks, and after four weeks); health-related quality of life using a validated instrument; ear pain (otalgia) or discomfort or local irritation. Secondary outcomes included hearing, serious complications and ototoxicity measured in several ways. Main results: We included 18 studies (2135 participants) with unclear or high risk of bias. 1. Systemic antibiotics versus no treatment/placebo It is very uncertain if there is a difference between systemic (intravenous) antibiotics and placebo in the resolution of ear discharge at between one and two weeks (risk ratio (RR) 8.47, 95% confidence interval (CI) 1.88 to 38.21; 33 participants; 1 study; very low-certainty evidence). The study did not report results for resolution of ear discharge after two weeks. Health-related quality of life was not reported. The evidence is very uncertain for hearing and serious (intracranial) complications. Ear pain and suspected ototoxicity were not reported. 2. Systemic antibiotics versus no treatment/placebo (both study arms received topical antibiotics) Six studies were included of which five presented useable data. There may be little or no difference in the resolution of ear discharge at between one to two weeks for oral ciprofloxacin compared to placebo or no treatment when ciprofloxacin ear drops were used in both intervention arms (RR 1.02, 95% CI 0.93 to 1.12; 390 participants; low-certainty evidence). No results after two weeks were reported. Health-related quality of life was not reported. The evidence is very uncertain for ear pain, serious complications and suspected ototoxicity. 3. Systemic antibiotics versus no treatment/placebo (both study arms received other background treatments) Two studies used topical antibiotics plus steroids as background treatment in both arms. It is very uncertain if there is a difference in resolution of ear discharge between metronidazole and placebo at four weeks (RR 0.91, 95% CI 0.51 to 1.65; 40 participants; 1 study; very low-certainty evidence). This study did not report other outcomes. It is also very uncertain if resolution of ear discharge at six weeks was improved with co-trimoxazole compared to placebo (RR 1.54, 95% CI 1.09 to 2.16; 98 participants; 1 study; very low-certainty evidence). Resolution of ear discharge was not reported at other time points. From the narrative report there was no evidence of a difference between groups for health-related quality of life, hearing or serious complications (very low-certainty evidence). One study (136 participants) used topical antiseptics as background treatment in both arms and found similar resolution of ear discharge between the amoxicillin and no treatment groups at three to four months (RR 1.03, 95% CI 0.75 to 1.41; 136 participants; 1 study; very low-certainty evidence). The narrative report indicated no evidence of differences in hearing or suspected ototoxicity (both very low-certainty evidence). No other outcomes were reported. 4. Different types of systemic antibiotics This is a summary of four comparisons, where different antibiotics were compared to each other. Eight studies compared different types of systemic antibiotics against each other: quinolones against beta-lactams (four studies), lincosamides against nitroimidazoles (one study) and comparisons of different types of beta-lactams (three studies). It was not possible to conclude if there was one class or type of systemic antibiotic that was better in terms of resolution of ear discharge. The studies did not report adverse events well. Authors' conclusions: There was a limited amount of evidence available to examine whether systemic antibiotics are effective in achieving resolution of ear discharge for people with CSOM. When used alone (with or without aural toileting), we are very uncertain if systemic antibiotics are more effective than placebo or no treatment. When added to an effective intervention such as topical antibiotics, there seems to be little or no difference in resolution of ear discharge (low-certainty evidence). Data were only available for certain classes of antibiotics and it is very uncertain whether one class of systemic antibiotic may be more effective than another. Adverse effects of systemic antibiotics were poorly reported in the studies included. As we found very sparse evidence for their efficacy, the possibility of adverse events may detract from their use for CSOM.
Article
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Background: Chronic suppurative otitis media (CSOM) is a chronic inflammation and often polymicrobial infection of the middle ear and mastoid cavity, characterised by ear discharge (otorrhoea) through a perforated tympanic membrane. The predominant symptoms of CSOM are ear discharge and hearing loss. Topical antibiotics act to kill or inhibit the growth of micro-organisms that may be responsible for the infection. Antibiotics can be used alone or in addition to other treatments for CSOM, such as steroids, antiseptics or ear cleaning (aural toileting). Antibiotics are commonly prescribed in combined preparations with steroids. Objectives: To assess the effects of adding a topical steroid to topical antibiotics in the treatment of people with chronic suppurative otitis media (CSOM). Search methods: The Cochrane ENT Information Specialist searched the Cochrane ENT Register; Central Register of Controlled Trials (CENTRAL via the Cochrane Register of Studies); Ovid MEDLINE; Ovid Embase; CINAHL; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the search was 16 March 2020. Selection criteria: We included randomised controlled trials (RCTs) with at least a one-week follow-up involving participants (adults and children) who had chronic ear discharge of unknown cause or CSOM, where the ear discharge had continued for more than two weeks. The interventions were any combination of a topical antibiotic agent(s) of any class and a topical corticosteroid (steroid) of any class, applied directly into the ear canal as ear drops, powders or irrigations, or as part of an aural toileting procedure. The two main comparisons were topical antibiotic and steroid compared to a) placebo or no intervention and b) another topical antibiotic. Data collection and analysis: We used the standard Cochrane methodological procedures. We used GRADE to assess the certainty of the evidence for each outcome. Our primary outcomes were: resolution of ear discharge or 'dry ear' (whether otoscopically confirmed or not), measured at between one week and up to two weeks, two weeks to up to four weeks and after four weeks; health-related quality of life; ear pain (otalgia) or discomfort or local irritation. Secondary outcomes included hearing, serious complications and ototoxicity. Main results: We included 17 studies addressing 11 treatment comparisons. A total of 1901 participants were included, with one study (40 ears) not reporting the number of participants recruited, which we therefore could not account for. No studies reported health-related quality of life. The main comparisons were: 1. Topical antibiotics with steroids versus placebo or no treatment Three studies (210 participants) compared a topical antibiotic-steroid to saline or no treatment. Resolution of discharge was not reported at between one to two weeks. One study (50 'high-risk' children) reported results at more than four weeks by ear and we could not adjust the results to by person. The study reported that 58% (of 41 ears) resolved with topical antibiotics compared with 50% (of 26 ears) with no treatment, but the evidence is very uncertain. One study (123 participants) noted minor side effects in 16% of participants in both the intervention and placebo groups (very low-certainty evidence). One study (123 participants) reported no change in bone-conduction hearing thresholds and reported no difference in tinnitus or balance problems between groups (very low-certainty evidence). One study (50 participants) reported serious complications, but it was not clear which group these patients were from, or whether the complications occurred pre- or post-treatment. One study (123 participants) reported that no side effects occurred in any participants (very low-certainty evidence). 2. Topical antibiotics with steroids versus topical antibiotics (same antibiotics) only Four studies (475 participants) were included in this comparison. Three studies (340 participants) compared topical antibiotic-steroid combinations to topical antibiotics alone. The evidence suggests little or no difference in resolution of discharge at one to two weeks: 82.7% versus 76.6% (risk ratio (RR) 1.08, 95% confidence interval (CI) 0.96 to 1.21; 335 participants; 3 studies (4 study arms); low-certainty evidence). No results for resolution of discharge after four weeks were reported. One study (110 participants) reported local itchiness but as there was only one episode in each group it is uncertain whether there is a difference (very low-certainty evidence). Three studies (395 participants) investigated suspected ototoxicity but it was not possible to determine whether there were differences between the groups for this outcome (very low-certainty evidence). No study reported serious complications. 3. Topical antibiotics with steroids compared to topical antibiotics alone (different antibiotics) Nine studies (981 participants plus 40 ears) evaluated a range of comparisons of topical non-quinolone antibiotic-steroid combinations versus topical quinolone antibiotics alone. Resolution of discharge may be greater with quinolone topical antibiotics alone at between one to two weeks compared with non-quinolone topical antibiotics with steroids: 82.1% versus 63.2% (RR 0.77, 95% CI 0.71 to 0.84; 7 studies; 903 participants, low-certainty evidence). Results for resolution of ear discharge after four weeks were not reported. One study (52 participants) reported usable data on ear pain, two studies (419 participants) reported hearing outcomes and one study (52 participants) reported balance problems. It was not possible to determine whether there were significant differences between the groups for these outcomes (very low-certainty evidence). Two studies (149 participants) reported no serious complications (very low-certainty evidence). Authors' conclusions: We are uncertain about the effectiveness of topical antibiotics with steroids in improving the resolution of ear discharge in patients with CSOM because of the limited amount of low-certainty evidence available. Amongst this uncertainty, we found no evidence that the addition of steroids to topical antibiotics affects the resolution of ear discharge. There is also low-certainty evidence that some types of topical antibiotics (without steroids) may be better than topical antibiotic/steroid combinations in improving resolution of discharge. There is also uncertainty about the relative effectiveness of different types of antibiotics; it is not possible to determine with any certainty whether or not quinolones are better or worse than aminoglycosides. These two groups of compounds have different adverse effect profiles, but there is insufficient evidence from the included studies to make any comment about these. In general, adverse effects were poorly reported.
Article
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Background: Chronic suppurative otitis media (CSOM), sometimes referred to as chronic otitis media (COM), is a chronic inflammation and often polymicrobial infection (involving more than one micro-organism) of the middle ear and mastoid cavity, characterised by ear discharge (otorrhoea) through a perforated tympanic membrane. The predominant symptoms of CSOM are ear discharge and hearing loss. Topical antibiotics, the most common treatment for CSOM, act to kill or inhibit the growth of micro-organisms that may be responsible for the infection. Antibiotics can be used alone or in addition to other treatments for CSOM, such as antiseptics or ear cleaning (aural toileting). Objectives: To assess the effects of topical antibiotics (without steroids) for people with CSOM. Search methods: The Cochrane ENT Information Specialist searched the Cochrane ENT Register; Central Register of Controlled Trials (CENTRAL via the Cochrane Register of Studies); Ovid MEDLINE; Ovid Embase; CINAHL; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the search was 1 April 2019. Selection criteria: We included randomised controlled trials (RCTs) with at least a one-week follow-up involving participants (adults and children) who had chronic ear discharge of unknown cause or CSOM, where the ear discharge had continued for more than two weeks. The interventions were any single, or combination of, topical antibiotic agent(s) of any class, applied directly into the ear canal as ear drops, powders or irrigations, or as part of an aural toileting procedure. The two main comparisons were topical antibiotic compared to a) placebo or no intervention and b) another topical antibiotic (e.g. topical antibiotic A versus topical antibiotic B). Within each comparison we separated studies where both groups of participants had received topical antibiotic a) alone or with aural toileting and b) on top of background treatment (such as systemic antibiotics). Data collection and analysis: We used the standard Cochrane methodological procedures. We used GRADE to assess the certainty of the evidence for each outcome. Our primary outcomes were: resolution of ear discharge or 'dry ear' (whether otoscopically confirmed or not), measured at between one week and up to two weeks, two weeks to up to four weeks and after four weeks; health-related quality of life using a validated instrument; ear pain (otalgia) or discomfort or local irritation. Secondary outcomes included hearing, serious complications and ototoxicity measured in several ways. Main results: We included 17 studies with a total of 2198 participants. Twelve studies reported the sample size in terms of participants (not ears); these had a total of 1797 participants. The remaining five studies reported both the number of participants and ears, representing 401 participants, or 510 ears. A: Topical antibiotics versus placebo or no treatment (with aural toilet in both arms and no other background treatment) One small study compared a topical antibiotic (ciprofloxacin) with placebo (saline). All participants received aural toilet. Although ciprofloxacin was better than saline in terms of resolution of discharge at one to two weeks: 84% versus 12% (risk ratio (RR) 6.74, 95% confidence interval (CI) 1.82 to 24.99; 35 participants, very low-certainty evidence), the very low certainty of the evidence means that it is very uncertain whether or not one intervention is better or worse than the other. The study authors reported that "no medical side-effects and worsening of audiological measurements related to this topical medication were detected" (very low-certainty evidence). B: Topical antibiotics versus placebo or no treatment (with use of oral antibiotics in both arms) Four studies compared topical ciprofloxacin to no treatment (three studies; 190 participants) or topical ceftizoxime to no treatment (one study; 248 participants). In each study all participants received the same antibiotic systemically (oral ciprofloxacin, injected ceftizoxime). In at least one study all participants received aural toilet. Useable data were only available from the first three studies; ciprofloxacin was better than no treatment, resolution of discharge occurring in 88.2% versus 60% at one to two weeks (RR 1.47, 95% CI 1.20 to 1.80; 2 studies, 150 participants; low-certainty evidence). None of the studies reported ear pain or discomfort/local irritation. C: Comparisons of different topical antibiotics The certainty of evidence for all outcomes in these comparisons is very low. Quinolones versus aminoglycosides Seven studies compared an aminoglycoside (gentamicin, neomycin or tobramycin) with ciprofloxacin (734 participants) or ofloxacin (214 participants). Whilst resolution of discharge at one to two weeks was higher in the quinolones group the very low certainty of the evidence means that it is very uncertain whether or not one intervention is better or worse than the other (RR 1.95, 95% CI 0.88 to 4.29; 6 studies, 694 participants). One study measured ear pain and reported no difference between the groups. Quinolones versus aminoglycosides/polymyxin B combination ±gramicidin We identified three studies but data on our primary outcome were only available in one study. Comparing ciprofloxacin to a neomycin/polymyxin B/gramicidin combination, for an unknown treatment duration (likely four weeks), ciprofloxacin was better (RR 1.12, 95% CI 1.03 to 1.22, 186 participants). A "few" patients experienced local irritation upon the first instillation of topical treatment (numbers/groups not stated). Others Other studies examined topical gentamicin versus a trimethoprim/sulphacetamide/polymixin B combination (91 participants) and rifampicin versus chloramphenicol (160 participants). Limited data were available and the findings were very uncertain. Authors' conclusions: We are uncertain about the effectiveness of topical antibiotics in improving resolution of ear discharge in patients with CSOM because of the limited amount of low-quality evidence available. However, amongst this uncertainty there is some evidence to suggest that the use of topical antibiotics may be effective when compared to placebo, or when used in addition to a systemic antibiotic. There is also uncertainty about the relative effectiveness of different types of antibiotics; it is not possible to determine with any certainty whether or not quinolones are better or worse than aminoglycosides. These two groups of compounds have different adverse effect profiles, but there is insufficient evidence from the included studies to make any comment about these. In general, adverse effects were poorly reported.