Ampicillin versus penicillin in the empiric therapy of extremely low-birthweight neonates at risk of early onset sepsis

Efficacy of Antibiotic Regimens for Sepsis or Possible Serious Bacterial Infection in Young Infants Aged 0 to 59 Days: A Systematic Review and Meta-analysis

CONTEXT

Sepsis is a leading cause of young infant mortality.

OBJECTIVE

To evaluate the efficacy of different antibiotic regimens to treat young infant sepsis or possible serious bacterial infection (PSBI) on clinical outcomes.

DATA SOURCES

MEDLINE, Embase, CINAHL, World Health Organization Global Index Medicus, Cochrane Central Registry of Trials.

STUDY SELECTION

We included randomized controlled trials (RCTs) of young infants 0 to 59 days with sepsis or PBSI (population) comparing the efficacy of antibiotic regimens (intervention) with alternate regimens or management (control) on clinical outcomes.

DATA EXTRACTION

We extracted data and assessed risk of bias in duplicate. We performed random-effects meta-analysis, and used Grading of Recommendations, Assessment, Development, and Evaluation to assess certainty of evidence.

RESULTS

Of 2390 publications, we included 41 RCTs (n = 18 054). Thirty-five trials were hospital-based and 6 were nonhospital-based. Meta-analysis of 4 trials demonstrated similar rates of treatment success with intramuscular/intravenous third generation cephalosporins versus intramuscular/intravenous penicillin or ampicillin + gentamicin (RR 1.03, 95% CI 0.93-1.13]; n = 1083; moderate certainty of evidence). Meta-analysis of 3 trials demonstrated similar rates of treatment failure with oral amoxicillin + intramuscular gentamicin versus intramuscular penicillin + gentamicin for nonhospital treatment of clinical severe illness (RR 0.86, 95% CI 0.72-1.02]; n = 5054; low certainty of evidence). Other studies were heterogeneous.

LIMITATIONS

RCTs evaluated heterogeneous regimens, limiting our ability to pool data.

CONCLUSIONS

We found limited evidence to support any single antibiotic regimen as superior to alternate regimens to treat young infant sepsis or PSBI.

Antibiotics, Analgesic Sedatives, and Antiseizure Medications Frequently Used in Critically Ill Neonates: A Narrative Review

Antibiotic, analgesic sedative, and antiseizure medications are among the most commonly used medications in preterm/sick neonates, who are at high risk of nosocomial infections, central nervous system complications, and are exposed to numerous painful/stressful procedures. These severe and potentially life-threatening complications may have serious short- and long-term consequences and should be prevented and/or promptly treated. The reported variability in the medications used in neonates indicates the lack of adequate neonatal studies regarding their effectiveness and safety. Important obstacles contributing to inadequate studies in preterm/sick infants include difficulties in obtaining parental consent, physicians' unwillingness to recruit preterm infants, the off-label use of many medications in neonates, and other scientific and ethical concerns. This review is an update on the use of antimicrobials (antifungals), analgesics (sedatives), and antiseizure medications in neonates, focusing on current evidence or knowledge gaps regarding their pharmacokinetics, indications, safety, dosage, and evidence-based guidelines for their optimal use in neonates. We also address the effects of early antibiotic use on the intestinal microbiome and its association with long-term immune-related diseases, obesity, and neurodevelopment (ND). Recommendations for empirical treatment and the emergence of pathogen resistance to antimicrobials and antifungals are also presented. Finally, future perspectives on the prevention, modification, or reversal of antibiotic resistance are discussed.

Antibiotic regimens for early-onset neonatal sepsis

BACKGROUND

Neonatal sepsis is a major cause of morbidity and mortality. It is the third leading cause of neonatal mortality globally constituting 13% of overall neonatal mortality. Despite the high burden of neonatal sepsis, high-quality evidence in diagnosis and treatment is scarce. Possibly due to the diagnostic challenges of sepsis and the relative immunosuppression of the newborn, many neonates receive antibiotics for suspected sepsis. Antibiotics have become the most used therapeutics in neonatal intensive care units. The last Cochrane Review was updated in 2004. Given the clinical importance, an updated systematic review assessing the effects of different antibiotic regimens for early-onset neonatal sepsis is needed.

OBJECTIVES

To assess the beneficial and harmful effects of different antibiotic regimens for early-onset neonatal sepsis.

SEARCH METHODS

We searched the following electronic databases: CENTRAL (2020, Issue 8); Ovid MEDLINE; Embase Ovid; CINAHL; LILACS; Science Citation Index EXPANDED and Conference Proceedings Citation Index - Science on 12 March 2021. We searched clinical trials databases and the reference lists of retrieved articles for randomised controlled trials (RCTs) and quasi-RCTs.

SELECTION CRITERIA

We included RCTs comparing different antibiotic regimens for early-onset neonatal sepsis. We included participants from birth to 72 hours of life at randomisation.

DATA COLLECTION AND ANALYSIS

Three review authors independently assessed studies for inclusion, extracted data, and assessed risk of bias. We used the GRADE approach to assess the certainty of evidence. Our primary outcome was all-cause mortality, and our secondary outcomes were: serious adverse events, respiratory support, circulatory support, nephrotoxicity, neurological developmental impairment, necrotising enterocolitis, and ototoxicity. Our primary time point of interest was at maximum follow-up.

MAIN RESULTS

We included five RCTs (865 participants). All trials were at high risk of bias. The certainty of the evidence according to GRADE was very low. The included trials assessed five different comparisons of antibiotics. We did not conduct any meta-analyses due to lack of relevant data. Of the five included trials one trial compared ampicillin plus gentamicin with benzylpenicillin plus gentamicin; one trial compared piperacillin plus tazobactam with amikacin; one trial compared ticarcillin plus clavulanic acid with piperacillin plus gentamicin; one trial compared piperacillin with ampicillin plus amikacin; and one trial compared ceftazidime with benzylpenicillin plus gentamicin. None of the five comparisons found any evidence of a difference when assessing all-cause mortality, serious adverse events, circulatory support, nephrotoxicity, neurological developmental impairment, or necrotising enterocolitis; however, none of the trials were near an information size that could contribute significantly to the evidence of the comparative benefits and risks of any particular antibiotic regimen. None of the trials assessed respiratory support or ototoxicity. The benefits and harms of different antibiotic regimens remain unclear due to the lack of well-powered trials and the high risk of systematic errors.

AUTHORS' CONCLUSIONS

Current evidence is insufficient to support any antibiotic regimen being superior to another. Large RCTs assessing different antibiotic regimens in early-onset neonatal sepsis with low risk of bias are warranted.

Antibiotic regimens for late-onset neonatal sepsis

BACKGROUND

Neonatal sepsis is a major cause of morbidity and mortality. It is the third leading cause of neonatal mortality globally constituting 13% of overall neonatal mortality. Despite the high burden of neonatal sepsis, high-quality evidence in diagnosis and treatment is scarce. Due to the diagnostic challenges of sepsis and the relative immunosuppression of the newborn, many neonates receive antibiotics for suspected sepsis. Antibiotics have become the most used therapeutics in neonatal intensive care units, and observational studies in high-income countries suggest that 83% to 94% of newborns treated with antibiotics for suspected sepsis have negative blood cultures. The last Cochrane Review was updated in 2005. There is a need for an updated systematic review assessing the effects of different antibiotic regimens for late-onset neonatal sepsis.

OBJECTIVES

To assess the beneficial and harmful effects of different antibiotic regimens for late-onset neonatal sepsis.

SEARCH METHODS

We searched the following electronic databases: CENTRAL (2021, Issue 3); Ovid MEDLINE; Embase Ovid; CINAHL; LILACS; Science Citation Index EXPANDED and Conference Proceedings Citation Index - Science on 12 March 2021. We also searched clinical trials databases and the reference lists of retrieved articles for randomised controlled trials (RCTs) and quasi-RCTs.

SELECTION CRITERIA

We included RCTs comparing different antibiotic regimens for late-onset neonatal sepsis. We included participants older than 72 hours of life at randomisation, suspected or diagnosed with neonatal sepsis, meningitis, osteomyelitis, endocarditis, or necrotising enterocolitis. We excluded trials that assessed treatment of fungal infections.

DATA COLLECTION AND ANALYSIS

Three review authors independently assessed studies for inclusion, extracted data, and assessed risk of bias. We used the GRADE approach to assess the certainty of evidence. Our primary outcome was all-cause mortality, and our secondary outcomes were: serious adverse events, respiratory support, circulatory support, nephrotoxicity, neurological developmental impairment, necrotising enterocolitis, and ototoxicity. Our primary time point of interest was at maximum follow-up.

MAIN RESULTS

We included five RCTs (580 participants). All trials were at high risk of bias, and had very low-certainty evidence. The five included trials assessed five different comparisons of antibiotics. We did not conduct a meta-analysis due to lack of relevant data. Of the five included trials one trial compared cefazolin plus amikacin with vancomycin plus amikacin; one trial compared ticarcillin plus clavulanic acid with flucloxacillin plus gentamicin; one trial compared cloxacillin plus amikacin with cefotaxime plus gentamicin; one trial compared meropenem with standard care (ampicillin plus gentamicin or cefotaxime plus gentamicin); and one trial compared vancomycin plus gentamicin with vancomycin plus aztreonam. None of the five comparisons found any evidence of a difference when assessing all-cause mortality, serious adverse events, circulatory support, nephrotoxicity, neurological developmental impairment, or necrotising enterocolitis; however, none of the trials were near an information size that could contribute significantly to the evidence of the comparative benefits and risks of any particular antibiotic regimen. None of the trials assessed respiratory support or ototoxicity. The benefits and harms of different antibiotic regimens remain unclear due to the lack of well-powered trials and the high risk of systematic errors.

AUTHORS' CONCLUSIONS

Current evidence is insufficient to support any antibiotic regimen being superior to another. RCTs assessing different antibiotic regimens in late-onset neonatal sepsis with low risks of bias are warranted.

Early-Onset Sepsis in Neonates - A Population-Based Study in South-West Norway From 1996 to 2018

Background: The epidemiology of early-onset sepsis (EOS) may change over time. Longitudinal surveillance of causative pathogens, antibiotic susceptibility patterns and antibiotic therapy is important for optimal therapy strategies. Objectives: To describe the incidence of culture-confirmed EOS, causative pathogens, antibiotic susceptibility patterns and antibiotic therapy over a 23-year period. Methods: Retrospective population-based study from a single-center neonatal intensive care unit at Stavanger University Hospital, Norway, covering a population in South-West Norway, during the 23-year period 1996-2018. Results: Of 104,377 live born infants, 101 infants (0.97/1,000) had culture-confirmed EOS; 89 with Gram positive and 12 with Gram-negative bacteria. The EOS-attributable mortality was 6/101 (5.8%). For the three most prevalent pathogens the incidences were; Group B streptococcus (GBS) 0.57/1,000, Escherichia coli 0.11/1,000 and viridans group streptococci (VGS) 0.10/1,000. GBS was the most common pathogen (59/93; 63%) in infants with gestational age (GA) ≥ 28 weeks. In contrast, among extremely preterm infants (GA <28 weeks) the incidence of E. coli infection was higher than for GBS infection. The second most common bacterial pathogens causing EOS among term infants were VGS. There was no change in the incidence of EOS for the entire study period, but from 2000 to 2018 there was a mean decline in EOS by 6% per year (95% CI 1%-10%) (p = 0.019). The incidences of GBS and E. coli did not change during the study period. The initial empirical antibiotic regimen for EOS was in all cases a combination of benzylpenicillin or ampicillin and an aminoglycoside, but in 21/101 (21%) of cases a broad-spectrum antibiotic was either added or substituted this regimen. In 2/101 (2%) EOS cases, the pathogens were nonsusceptible to the empirical antibiotic regimen. All E. coli isolates were susceptible to aminoglycosides. Conclusion: GBS was the most common causative pathogens in EOS, but E. coli dominated in infants with GA <28 weeks. There was no change in the incidence of EOS during the entire study period. The current empiric regimen with benzylpenicillin and gentamicin provides a very high coverage for EOS in our setting.

Drugs for the Prevention and Treatment of Sepsis in the Newborn

Antimicrobial medications are the most commonly used medications in the neonatal intensive care unit. Antibiotics are used for infection prophylaxis, empiric treatment, and definitive treatment of confirmed infection. The choice of medication should be informed by the epidemiology and microbiology of infection in specific clinical scenarios and by the clinical condition of the infant. Understanding evolving pathogen susceptibility to antimicrobials and key pharmacotherapy determinants in neonates can inform optimal antibiotic use.

Electronic Health Records and Pharmacokinetic Modeling to Assess the Relationship between Ampicillin Exposure and Seizure Risk in Neonates

OBJECTIVE

To evaluate the relationship between ampicillin dosing, exposure, and seizures.

STUDY DESIGN

This was a retrospective observational cohort study of electronic health record (EHR) data combined with pharmacokinetic model derived drug exposure predictions. We used the EHR from 348 Pediatrix Medical Group neonatal intensive care units from 1997 to 2012. We included all infants 24-41 weeks gestational age, 500-5400 g birth weight, first exposed to ampicillin prior to 25 days postnatal age. Using a 1-compartment pharmacokinetic model and EHR data, we simulated maximum ampicillin concentration at steady state (Cmaxss, µg/mL) and area under the concentration time curve from 0 to 24 hours (AUC24, µg*h/dL). Using multivariable logistic regression, we evaluated association between ampicillin dosing, exposure, and seizures as documented in the EHR.

RESULTS

We identified 131 723 infants receiving 134 041 courses of ampicillin for 653 506 infant-days of exposure. The median daily dose was 200 mg/kg/d (25th, 75th percentile; 100, 200). Median Cmaxss and AUC24 were 256.6 µg/mL (164.3, 291.5) and 2593 µg*h/dL (1917, 3334). On multivariable analysis, dosing was not associated with seizures. However increasing Cmaxss (OR = 1.10, 95% CI 1.03, 1.17) and AUC24 (OR 1.11, 95% CI 1.05, 1.18) were associated with increased odds of seizures.

CONCLUSIONS

In this cohort of hospitalized infants, higher ampicillin exposure was associated with seizures as documented in the EHR.