Efficacy and safety of intravenous colistin in preterm infants with nosocomial sepsis caused by Acinetobacter baumannii

Reintroduction of Legacy Antibiotics in Neonatal Sepsis: The Special Role of Fosfomycin and Colistin

Neonatal sepsis is a leading cause of morbidity and mortality in neonates, particularly in low- and middle-income countries. The emergence of antimicrobial resistance is a rapidly growing global problem. A significant proportion of the pathogens that commonly cause neonatal sepsis are resistant to multiple antibiotics. Therefore, for the empirical treatment of neonatal sepsis, the repurposing of older antibiotics that are effective against multidrug-resistant pathogens is being investigated. This review aims to provide an overview of current research and experience using the repurposed antibiotics colistin and fosfomycin for the empirical treatment of neonatal sepsis. Based on current knowledge, colistin and fosfomycin may be potentially helpful for the empirical treatment of sepsis in neonates due to their efficacy against a wide range of pathogens and acceptable safety profile.

Ten-year Single Center Experience With Colistin Therapy in NICU

BACKGROUND

Colistin, a cationic polypeptide antibiotic of the polymyxin class has come back into use due to its potent antimicrobial activity against multidrug-resistant Gram-negative bacteria and the lack of new antibiotics. The purpose of this study was to assess the critically ill infants treated with colistin in our neonatal intensive care unit and to identify predisposing factors for the emergence of acute kidney injury (AKI) following colistin treatment.

METHODS

This was a retrospective case-control study that included infants with proven or suspected nosocomial infections in the neonatal intensive care unit of a University Hospital between January 2012 and March 2022. Over the same time period, the clinical and laboratory characteristics and outcomes of patients who received antibiotic combination with colistin were compared to patients who received antibiotic combination without colistin.

RESULTS

A total of 77 patients were in the colistin group (ColG) and 77 patients were in the control group. The demographic and clinical characteristics of the study groups were similar. In the ColG compared to the control group, hyponatremia, hypokalemia, hypophosphatemia, hypomagnesia and AKI were all more prevalent ( P < 0.05). The most important finding in our study was the higher incidence of AKI and mortality in ColG, as well as the increasing nephrotoxic effect of other medications when used in conjunction with colistin.

CONCLUSION

During colistin therapy, newborn infants must be closely monitored for AKI. Clinicians should be aware of an increased incidence of hyponatremia, hypokalemia, hypophosphatemia, hypomagnesia, AKI and its consequences in infants given colistin. As awareness increases, harmful effects will decrease.

Incidence of Antimicrobial-Associated Acute Kidney Injury in Children: A Structured Review

Acute kidney injury (AKI) is a commonly reported adverse effect of administration of antimicrobials. While AKI can be associated with poorer outcomes, there is little information available to understand rates of AKI in children exposed to various antimicrobials. We performed a structured review using the PubMed and Embase databases. Articles were included if they provided an AKI definition in patients who were < 19 years of age receiving an antimicrobial and reported the frequency of AKI. Author-defined AKI rates were calculated for each study and mean pooled estimates for each antimicrobial were derived from among all study participants. Pooled estimates were also derived for those studies that reported AKI according to pRIFLE (pediatric risk, injury, failure, loss, end stage criteria), AKIN (acute kidney injury network), or KDIGO (kidney disease improving global outcomes) creatinine criteria. A total of 122 studies evaluating 28 antimicrobials met the inclusion criteria. Vancomycin was the most commonly studied drug: 11,514 courses across 44 included studies. Among the 27,285 antimicrobial exposures, the overall AKI rate was 13.2% (range 0-42.1% by drug), but the rate of AKI varied widely across studies (range 0-68.8%). Cidofovir (42.1%) and conventional amphotericin B (37.0%) had the highest pooled rates of author-defined AKI. Eighty-one studies used pRIFLE, AKIN, or KDIGO AKI criteria and the pooled rates of AKI were similar to author-defined AKI rates. In conclusion, antimicrobial-associated AKI is reported to occur frequently in children, but the rates of AKI varies widely across studies and drugs. Most published studies examined hospitalized patients and heterogeneity in study populations and in author definitions of AKI are barriers to a comparison of nephrotoxicity risk among antimicrobials in children.

Colistin use in a carbapenem-resistant Enterobacterales outbreak at a South African neonatal unit

Background

Colistin is increasingly prescribed for neonates with carbapenem-resistant Enterobacterales (CRE) infections.

Objectives

We described patient demographics, infection episodes, treatment and clinical outcomes, colistin related adverse events and relatedness of isolates in neonates with clinically confirmed or clinically suspected CRE infections.

Method

The authors retrospectively reviewed culture-confirmed and clinically suspected culture-negative CRE infections at a South African neonatal unit during a CRE outbreak.

Results

Fifty-three neonates (median gestational age 29 weeks and birth weight 1185 g) were included. Twenty-three of 53 neonates (43%) had culture-confirmed CRE (17 received colistin; 6 died without receiving colistin) and 30 (57%) received colistin for clinically suspected CRE infection but were ultimately culture-negative. Prior respiratory support and surgical conditions were present in 37/53 (70%) and 19/53 (36%) neonates, respectively. Crude mortality was high (20/53; 38%) with no significant difference between culture-confirmed CRE versus clinically suspected culture-negative CRE groups (10/23 [44%] vs 10/30 [33%]; p = 0.45). Hypomagnesaemia (10/38; 26%) and hypokalaemia (15/38; 40%) were frequent; acute kidney injury was rare (1/44; 2%). Three CRE infection clusters were identified by genotypic analysis of 20 available isolates (18 [90%] bla _NDM-1 [New Delhi metallo-beta-lactamase], 2 [10%] bla _OXA [oxacillinase]-48).

Conclusion

Neonates receiving colistin therapy were predominantly preterm, with multiple risk factors for infection. Colistin-associated electrolyte derangement was frequent. Over one-third of neonates died. Bla _NDM-1 was the most frequent carbapenemase gene identified in the outbreak isolates.

Contribution

Colistin was safely used during an Enterobacterales outbreak in predominantly premature and surgical neonates. The mortality was high.

Can magnesium sulfate prophylaxis reduce colistin nephrotoxicity?

The study aimed to investigate the role of magnesium sulfate prophylaxis in nephrotoxicity caused by colistin. Thirty Wistar Albino rats were divided into four groups: control, colistin, magnesium (Mg), and Mg+colistin. The drugs were administered to the groups for seven days. Urea-creatinine values were measured at the beginning (T0) and end (T1) of the study. Malondialdehyde (MDA) levels were measured in plasma and kidney tissue, glutathione (GSH) levels were analyzed in the erythrocyte and kidney tissues. At the end of the study, the semiquantitative score (SQS) was calculated by the histopathological examination of the kidneys. Urea values significantly decreased in Mg and Mg+colistin groups compared to the baseline (p=0.013 and p=0.001). At the time of T1, these groups had significantly lower urea values than the colistin and control groups. Creatinine value was significantly increased in the colistin group compared to baseline (p=0.005), the creatinine value in the colistin group was significantly higher than the Mg+colistin group (p=0.011). Plasma MDA levels were significantly higher in the colistin group compared to the other groups at the time of T1 (p<0.001). The Mg+colistin group had lower renal MDA levels than the colistin group. The colistin group had significantly higher renal tubular grade (p=0.035), renal affected area (p<0.001), and SQS (p=0.001) than the Mg+colistin group. The results of the study suggested that Mg sulfate may have a nephrotoxicity-reducing effect on colistin.

Safety and efficacy of colistin and fluoroquinolone in neonatal persistent late-onset sepsis

Growing resistance of microorganisms to antibiotics for the treatment of late-onset sepsis (LOS) in premature infants has led physicians to use antibiotics that are not well studied in neonatal populations. We aimed to determine the efficacy and safety of colistin and fluoroquinolone for the treatment of persistent LOS. We retrospectively reviewed infants with gram-negative LOS, who received either colistin or fluoroquinolone therapy, to determine if there was a significant difference in kidney and liver function tests and electrolyte levels before, during, and at the end of the treatment. Infants who received colistin and fluoroquinolone had 17 and 34 positive cultures with gram-negative organisms, respectively. Multi-drug resistant organisms were more common in infants who received colistin than in those who received fluoroquinolone. Microbiological clearance was found to be higher in infants treated with fluoroquinolone than in those treated with colistin. In both the groups, the median levels of kidney and liver function tests and electrolytes showed a significant increase during the treatment. The prescription of colistin and fluoroquinolones should be reserved for cases with no other safe and effective alternatives.

Can magnesium sulfate prophylaxis reduce colistin nephrotoxicity?

The study aimed to investigate the role of magnesium sulfate prophylaxis in nephrotoxicity caused by colistin. Thirty Wistar Albino rats were divided into four groups: control, colistin, magnesium (Mg), and Mg+colistin. The drugs were administered to the groups for seven days. Urea-creatinine values were measured at the beginning (T0) and end (T1) of the study. Malondialdehyde (MDA) levels were measured in plasma and kidney tissue, glutathione (GSH) levels were analyzed in the erythrocyte and kidney tissues. At the end of the study, the semiquantitative score (SQS) was calculated by the histopathological examination of the kidneys. Urea values significantly decreased in Mg and Mg+colistin groups compared to the baseline (p=0.013 and p=0.001). At the time of T1, these groups had significantly lower urea values than the colistin and control groups. Creatinine value was significantly increased in the colistin group compared to baseline (p=0.005), the creatinine value in the colistin group was significantly higher than the Mg+colistin group (p=0.011). Plasma MDA levels were significantly higher in the colistin group compared to the other groups at the time of T1 (p<0.001). The Mg+colistin group had lower renal MDA levels than the colistin group. The colistin group had significantly higher renal tubular grade (p=0.035), renal affected area (p<0.001), and SQS (p=0.001) than the Mg+colistin group. The results of the study suggested that Mg sulfate may have a nephrotoxicity-reducing effect on colistin.

Systematic review on estimated rates of nephrotoxicity and neurotoxicity in patients treated with polymyxins

BACKGROUND

Nephrotoxicity and neurotoxicity are commonly associated with polymyxin treatment; however, the emergence of multidrug-resistant Gram-negative bacteria with limited therapeutic options has resulted in increased use of polymyxins.

OBJECTIVES

To determine the rates of nephrotoxicity and neurotoxicity during polymyxin treatment and whether any factors influence these.

DATA SOURCES

Medline, Embase and Cochrane Library databases were searched on 2 January 2020.

STUDY ELIGIBILITY CRITERIA

Studies reporting nephrotoxicity and/or neurotoxicity rates in patients with infections treated with polymyxins were included. Reviews, meta-analyses and reports not in English were excluded.

PARTICIPANTS

Patients hospitalized with infections treated with systemic or inhaled polymyxins were included. For comparative analyses, patients treated with non-polymyxin-based regimens were also included.

METHODS

Meta-analyses were performed using a random-effects model; subgroup meta-analyses were conducted where data permitted using a mixed-effects model.

RESULTS

In total, 237 reports of randomized controlled trials, cohort and case-control studies were eligible for inclusion; most were single-arm observational studies. Nephrotoxic events in 35,569 patients receiving polymyxins were analysed. Overall nephrotoxicity rate was 0.282 (95% confidence interval (CI) 0.259-0.307). When excluding studies where >50% of patients received inhaled-only polymyxin treatment or nephrotoxicity assessment was by methods other than internationally recognized criteria (RIFLE, KDIGO or AKIN), the nephrotoxicity rate was 0.391 (95% CI 0.364-0.419). The odds of nephrotoxicity were greater with polymyxin therapies compared to non-polymyxin-based regimens (odds ratio 2.23 (95% CI 1.58-3.15); p < 0.001). Meta-analyses showed a significant effect of polymyxin type, dose, patient age, number of concomitant nephrotoxins and use of diuretics, glycopeptides or vasopressors on the rate of nephrotoxicity. Polymyxin therapies were not associated with a significantly different rate of neurotoxicity than non-polymyxin-based regimens (p 0.051). The overall rate of neurotoxicity during polymyxin therapy was 0.030 (95% CI 0.020-0.043).

CONCLUSIONS

Polymyxins are associated with a higher risk of nephrotoxicity than non-polymyxin-based regimens.

Efficacy of colistin in multidrug-resistant neonatal sepsis: experience from a tertiary care center in Karachi, Pakistan

OBJECTIVE

Infections with multidrug-resistant organisms (MDROs) such as Gram-negative bacteria have high morbidity and mortality with limited treatment options. Colistin, an antibiotic active against MDRO, was rarely used due to frequent adverse effects, but its use has now been recommended among adults. In this study, we determined the efficacy of colistin for the treatment of sepsis in neonates.

DESIGN/SETTING/PATIENTS/OUTCOMES

We conducted a retrospective record review of all neonates admitted to the neonatal intensive care unit of Aga Khan University Hospital, Karachi, Pakistan, between June 2015 and June 2018, who had sepsis and received colistin by intravenous, inhalation and/or intrathecal routes. Predictors of colistin efficacy, for neonatal survival and microbial clearance, were assessed using multiple logistic regression.

RESULTS

153 neonates received colistin; 120 had culture-proven sepsis; and 93 had MDR-GNB (84 colistin-sensitive). 111 (72.5%) neonates survived and were discharged from hospital; 82.6% had microbial clearance. Neonates with colistin-sensitive bacteria (adjusted OR (AOR)=3.2, 95% CI 2.8 to 4.0), and those in which colistin therapy started early (AOR=7.2, 95% CI 3.5 to 13.6) were more likely to survive. Neonates with increased gestational age (AOR=1.9, 95% CI 1.5 to 3.0), higher weight (AOR=5.4, 95% CI 3.3 to 11.8) and later onset of sepsis (AOR=4.3, 95% CI 2.0 to 9.0) had higher survival. Adverse events included nephrotoxicity in 5.2%; 13.7% developed seizures and 18.3% had electrolyte imbalance.

CONCLUSIONS

Colistin therapy was associated with survival among neonates suffering from MDR-GNB sepsis. The frequency of side effects was moderate.

The Use of Colistin for the Treatment of Multidrug-resistant Gram-negative Infections in Neonates and Infants: A Review of the Literature

In this review, we report the available data regarding efficacy, safety and pharmacokinetics of colistin in the treatment of multidrug-resistant Gram-negative bacteria in neonates and infants. Seventeen clinical studies, involving 312 patients, and 3 pharmacokinetics studies were identified. Blood stream infection was the most common source of infection, followed by pneumonia and meningitis/ventriculitis. In most cases, colistin was administered in association with other antibiotics. The most common route of administration was intravenous, with colistimethate doses ranging from 25,000 to 225,000 IU/kg/day divided into 2 or 3 doses. A recent pharmacokinetic study suggested that the appropriate intravenous dose should be >150,000 IU/kg/day. Microbiologic cure was obtained in 94.2% of patients and survival was 76.6%. The combination of intraventricular and intravenous colistin should be used in meningitis/ventriculitis. Nebulized colistin should be used as adjunctive treatment, but not as monotherapy. Nephrotoxicity and apnea were reported in 5.8% and 3.9% of patients respectively.The use of colistin for multidrug-resistant Gram-negative infections in neonates and infants is effective and safe, but the quality of studies is moderate. The optimal intravenous dose should be higher than that indicated in most reports.

Use of Colistin in Critically Ill Patients

Due to lack of better therapeutic options, colistin use for extensively drug-resistant Gram-negative organisms was revived in the past two decades, including in patients in intensive-care units (ICU). There are multiple knowledge gaps pertaining to the clinical use and utility of colistin in critically-ill patients, but due to lack of options, it is used in these high risk patients. In this chapter, we critically review the various topics pertaining to colistin use in critically-ill patients, while highlighting the (lack of) controlled evidence supporting common current practices pertaining to colistin use by clinicians.

The use of polymyxins to treat carbapenem resistant infections in neonates and children

INTRODUCTION

The incidence of healthcare-associated multidrug resistant bacterial infections, particularly due to carbapenem resistant organisms, has been on the rise globally. Among these are the carbapenem resistant Acinetobacter baumannii and Enterobacteriaceae, which have been responsible for numerous outbreaks in neonatal units. The polymyxins (colistin and polymyxin B) are considered to be the last resort antibiotics for treating such infections. However, pharmacokinetic and pharmacodynamic data on the use of polymyxins in neonates and children are very limited, and there are safety concerns.

AREAS COVERED

In this review, the authors summarize the global burden of multidrug resistance, particularly carbapenem resistance, in the neonatal and paediatric population, and the potential wider use of polymyxins in treating these infections.

EXPERT OPINION

Both colistin and polymyxin B have similar efficacy in treating multidrug resistant infections but have safety concerns. However, polymyxin B appears to be a better therapeutic option, with more rapid and higher steady state concentrations achieved compared to colistin and less reported nephrotoxicity. There is virtually no data in neonates and children currently; there is therefore an urgent need for pharmacokinetic and safety trials in these populations to determine the optimal drug and dosing regimens and provide recommendations for their use against carbapenem resistant infections.

Nephrotoxicity prevalence in patients treated with polymyxins: a systematic review with meta-analysis of observational studies

Colistin and polymyxin B are increasingly reintroduced in clinical practice due to the absence of effective antibiotics for the treatment of emerging infections caused by gram-negative bacteria. The synthesis of current evidence on the characteristics of polymyxins, especially regarding nephrotoxicity, is necessary. This study aims to conduct a systematic review and meta-analysis of cohort-type observational studies in order to identify the prevalence of nephrotoxicity in patients treated with either colistin or polymyxin B. PubMed, Scopus, and DOAJ electronic databases were searched, and manual searches were done. Cohort studies evaluating renal damage (nephrotoxicity) in adult patients caused by colistin or polymyxin B were included. Meta-analyses of the prevalence of nephrotoxicity as well as cumulative meta-analysis and meta-regression were conducted. After the systematic searches, 95 cohorts (n = 7911 patients) were included for analysis. The nephrotoxicity prevalence was 26.7% [confidence interval (CI) 95%: 22.8-30.9%] for colistin and 29.8% (CI 23.8-36.7%) for polymyxin B (P = 0.720). The publication year of the studies, the criteria used to classify renal damage, and the nephrotoxicity as primary or secondary outcome showed a significant influence on the adverse event rates.

Efficacy and Safety of Intravenous Colistin in Very Low Birth Weight Preterm Infants

BACKGROUND

Given the severity and high mortality of multidrug-resistant Gram-negative bacilli (MDR-GNB) infections, the use of colistin will increase in patients with MDR-GNB infection.

OBJECTIVE

This study aims to assess the efficacy and safety of intravenous colistin in very low birth weight (VLBW; birth weight < 1500 g) preterm infants.

METHODS

We retrospectively analyzed the medical records of patients who received colistin between June 2016 and December 2017. The patients were assigned to two groups: the VLBW group and the non-VLBW group. Both groups were evaluated for response to treatment and adverse effects.

RESULTS

In total, 66 infants who received colistin therapy were included; of these, 28 infants were VLBW. All of our patients received standard colistin treatment of 5 mg/kg per day in three doses and the median duration of colistin treatment was 14 days. No significant differences were observed between the groups with respect to the efficacy of colistin (defined as showing microbiological clearance in control cultures and the absence of mortality during treatment) (89.3 vs 86.8%, p > 0.99). Serum magnesium and potassium levels were significantly lower in the VLBW group than in the non-VLBW group during colistin therapy (magnesium, 1.30 vs 1.70 mg/dL, p < 0.001; potassium, 3.6 vs 4.6 mEq/L, p < 0.001). Acute kidney injury was observed in four infants in the VLBW group and one in the non-VLBW group, without significant differences (p = 0.15).

CONCLUSIONS

Colistin administration appears to be efficacious in VLBW infants; however, renal function tests and serum electrolytes should be monitored more closely in these infants during treatment.

Verona integron-encoded metallo-β-lactamase-producing Klebsiella pneumoniae sepsis in an extremely premature infant

During the course of an outbreak due to Verona integron-encoded Metallo-β-lactamase (VIM)-producing Klebsiella pneumonia (KP) in the neonatal intensive care unit (NICU) of Maggiore Hospital in Bologna (Italy), an 8-day-old extremely low birth weight (ELBW) infant developed a severe ventilator-associated pneumonia (VAP) with concomitant bacteraemia. Although the microorganism was susceptible only to colistin and tigecycline, the patient was successfully treated with a combination of antibiotics including high-dosage, prolonged infusion of meropenem (MEM) and intravenous plus aerosolised gentamicin (GEN). This report highlights that, even when the microorganism is considered non-susceptible to MEM and GEN, the combination of these two agents could have a significant survival benefit.

Intravenous polymyxins: Revival with puzzle

With the increasing incidence of multi-drug resistant strains, especially carbapenem resistant strains, polymyxsins (mainly colistin and polymyxin B) based regimens seem to be a revival as an effective treatment of last resort in these infections. Evidence from 47 clinical trials or case series we reviewed showed that polymyxins based regimens are effective and have less toxicity compared with previous trials. When used alone, the mortality of intravenous polymyxsins ranged from 0% to 74.3%, clinical response (cure and improvement) rate was 7-82.1%, and microbiological eradication was 27.3-73.9%. The main reasons for the combination therapy are to get potential synergistic effects and to prevent the selection of heteroresistant strains. Several studies showed combination therapy seemed to be more effective than monotherapy, though a few doubts remain. Clinically, polymyxsins can be used in combination with several antibiotics, such as carberpenem, sulbactam, tigecycline, fosfomycin, glycopeptide, rifampicin and so on, but the optimal combination regimen is yet to be confirmed. The optimal dose of polymyxins is also controversial. With the limited clinical evidence, it's suggested loading dose regimens may be more effective, but more attention should be paid to adverse effects. Although recommended in some studies, high dose polymxins regimens with inconsistent clinical evidence need more trials to confirm. It is important to note that concerning dosing regimens, colistin and polymyxin B are not quite the same. In renal impaired patients polymyxin B should be prescribed without dosing adjustment. Risk of renal failure may increase in the following situations, such as the combination of intravenous colistin plus intravenous vancomycin, higher doses-colistin, and intravenous colistin combined with inhalational colistin. In conclusion, there're still controversies in combination regimens, dosing strategies and so on. Prospective trials of lager sample size are needed.

Antimicrobial-resistant Gram-negative infections in neonates: burden of disease and challenges in treatment

PURPOSE OF REVIEW

This review summarizes the main challenges of antimicrobial resistance (AMR) in the neonatal population with a special focus on multidrug-resistant (MDR) Gram-negative pathogens.

RECENT FINDINGS

MDR-Gram-negative bacteria are a great concern in the neonatal population, with a worldwide rise in the reported incidence and with very limited therapeutic options. Extended-spectrum β-lactamase and carbapenem-resistant Enterobacteriaceae (CRE) have been reported as responsible for neonatal ICU outbreaks. Hospital data from low/middle-income countries show high proportions of isolates from neonates resistant to the WHO first-line and second-line recommended treatments. The spread of CRE has resulted in old antibiotics, such as colistin and fosfomycin, to be considered as alternative treatment options, despite the paucity of available data on safety and appropriate dosage.

SUMMARY

Improved global neonatal AMR surveillance programmes including both epidemiology and clinical outcomes are critical for defining the burden and designing interventions. The optimal empiric treatment for neonatal sepsis in settings of high rates of AMR is currently unknown. Both strategic trials of older antibiotics and regulatory trials of new antibiotics are required to improve clinical outcomes in MDR-Gram-negative neonatal sepsis.

Colistin use in critically ill neonates: A case-control study

BACKGROUND

The aim of this study was to assess the safety and efficacy of colistin use in critically ill neonates.

METHODS

This was a case-control study that included newborn infants with proven or suspected nosocomial infections between January 2012 and October 2015, at two centers in Diyarbakir, Turkey. The clinical and laboratory characteristics and outcomes of patients who received colistin therapy were reviewed and compared to patients who were treated with antimicrobial agents other than colistin during the same period.

RESULTS

Forty-seven cases who received intravenous colistin (colistin group) and 59 control patients (control group) were included. There were no significant differences between the groups regarding outcomes and nephrotoxicity, including acute renal failure. Colistin therapy was associated with significantly reduced serum magnesium (1.38 ± 0.39 mg/dL vs. 1.96 ± 0.39 mg/dL, p < 0.001) and hypokalemia (46.8% vs. 25.4%, p = 0.026). The patients who received colistin also had longer hospital stays (43 (32-70) days vs. 39 (28-55) days, p = 0.047), a higher rate of previous carbapenem exposure (40.4% vs. 11.9%, p = 0.001), and a higher age at the onset of infection (13 (10-21) days vs. 11 (9-15) days, p = 0.03).

CONCLUSION

This study showed that colistin was both effective and safe for treating neonatal infections caused by multidrug-resistant gram-negative bacteria. However, intravenous colistin use was significantly associated with hypomagnesemia and hypokalemia.

Colistin Use in Neonates and Children With Infections Due to Carbapenem-resistant Bacteria

Current evidence on the use of colistin in pediatric patients for infections caused by carbapenem-resistant bacteria is based on retrospective case series. The coadministration of colistin with other antimicrobial agents was associated with a relatively low rate of nephrotoxicity and a favorable outcome in >70% of these patients. Further study of colistin pharmacokinetics in children and neonates will likely lead to optimization of dosage recommendations.

Intravenous Colistin in the treatment of multidrug-resistant Acinetobacter in neonates

BACKGROUND

Neonatal sepsis caused by multidrug-resistant gram-negative bacteria has been reported in different parts of the world. It is a major threat to neonatal care, carrying a high rate of morbidity and mortality. While Colistin is the treatment of choice, few studies have reported its use in neonatal patients.

METHODS

A retrospective descriptive study of all neonatal patients who had multidrug-resistant Acinetobacter sepsis and were treated with Colistin over a 2-year period. Patients' charts and hospital laboratory data were reviewed.

RESULTS

During the study period, 21 newborns were treated with Colistin. All had sepsis evident by positive blood culture and clinical signs of sepsis. The median gestational age and birth weight were 33 weeks (26-39) and 1700 g (700-3600), respectively. Nine (43 %) were very low birth weight infants. Eighteen (86 %) were preterm infants. Nineteen (91 %) newborns survived. No renal impairment is documented in any of our patients. Fourteen (67 %) of our patients had elevated eosinophil counts following Colistin treatment, for those patients, the average eosinophilic counts ± standard deviation before and after Colistin therapy were 149.08 ± 190.38 to 1193 ± 523.29, respectively, with a p value of less than 0.0001.

CONCLUSION

Our study showed that Colistin was both effective and safe for treating multidrug-resistant Acinetobacter neonatal sepsis. This is a retrospective study. No universal protocol was used for the patients. The factors that might affect the response or cause side effects are difficult to evaluate.

Safety and Efficacy of Intravenous Colistin in Neonates With Culture Proven Sepsis

Background:

Although it is well described among adults, intravenous colistin use and its associated toxicities in newborns are poorly understood.

Objectives:

We present our experience of efficacy and safety of intravenous colistin in the treatment of sepsis in term and preterm neonates.

Patients and Methods:

The records of neonates who received colistin between January 2013 and February 2014 were retrospectively reviewed. All neonates with culture proven nosocomial infections due to multidrug resistant organisms and treated continuously with colistin for more than 72 hours were included in the study.

Results:

Patients were evaluated for clinical and microbiological response to the drug and its and side effects. Twelve newborn infants with mean 31.8 ± 3.5 weeks gestational age and median 1482 (810 - 3200) gram birth weight were included. 11/12 (91.7%) patients showed microbiological clearance with intravenous colistin. One patient who had recurrent cerebrospinal fluid positive culture was treated with intraventricular colistin. The major side effects observed was hyponatremia and hypokalemia in 2 (16.6%) patients, all infants required magnesium supplementation.

Conclusions:

Intravenous colistin administration appears to be safe and efficacious for multidrug-resistant gram-negative infections in neonates, including preterm infants. However, we believe that large prospective controlled studies are needed to confirm its efficacy and safety in neonates.