A randomized, prospective study comparing once-daily gentamicin versus thrice-daily gentamicin in the treatment of puerperal infection

Neonatal Serum Gentamicin Concentrations and Outcomes Following Maternal Once-Daily Gentamicin Dosing

OBJECTIVE

This study evaluated newborn gentamicin serum concentrations after birth and the effects on the newborn after extended interval gentamicin dosing in peripartum mothers.

METHODS

This was a single-center, retrospective chart review of neonates born to mothers that received peripartum once-daily gentamicin dosing of approximately 5 mg/kg within 12 hours of delivery. A gentamicin serum concentration was obtained immediately after birth in the newborn. The primary outcome was initial neonatal gentamicin serum concentration after birth. Several secondary outcomes were evaluated including nephrotoxicity and ototoxicity. A subgroup analysis comparing baseline demographics of mother-newborn dyads with birth neonatal serum concentrations of less than 2 mcg/mL versus 2 mcg/mL or greater was performed.

RESULTS

A total of 32 mother-newborn dyads were included. Newborns had a median gestational age of 39.4 weeks and median birth weight of 3.4 kg. The mean initial gentamicin serum concentration was elevated at 3.1 ± 1.9 mcg/mL among all newborns. The median maternal dose based on actual body weight in newborns with gentamicin serum concentrations less than 2 mcg/mL was 3.5 (IQR, 3.3-4.8) mg/kg versus 4.8 (IQR, 4.3-5.2) mg/kg in those that had serum concentrations of 2 mcg/mL or greater (p = 0.025). All newborn gentamicin serum concentrations were less than 2 mcg/mL for maternal doses given less than 1 hour prior to delivery (n = 8). There were no significant differences in nephrotoxicity or ototoxicity.

CONCLUSIONS

Peripartum once daily dosing of gentamicin administered between 1 to 12 hours of birth may lead to clinically significant serum concentrations in newborns.

Gentamicin Vestibulotoxicity: Further Insights From a Large Clinical Series

OBJECTIVE

To review insights gained from a 21-year experience with gentamicin-induced vestibulotoxicity including differences in vestibulotoxicity between single daily dosing (SDD) and multiple daily dosing (MDD) regimens.

STUDY DESIGN

Retrospective case series.

SETTING

Tertiary care center.

PATIENTS

Patients with gentamicin vestibulotoxicity referred to the Hertz Multidisciplinary Neurotology Clinic between January 1993 and September 2014.

INTERVENTION

None.

MAIN OUTCOME MEASURES

Spectrum of vestibular dysfunction measured using videonystagmography, vestibular evoked myogenic potentials, video head impulse testing, and magnetic scleral search coil testing.

RESULTS

Of 53 patients with gentamicin-induced vestibulotoxicity, 24 received SDD and 29 received MDD treatment. The most common indications for treatment were sepsis, endocarditis, and osteomyelitis. Angular acceleration receptor function (semicircular canals) was more commonly affected than linear acceleration receptor function (otolithic organ of the saccule; 100% vs. 62%). A significant proportion of patients (53%) developed vestibulotoxicity in the absence of nephrotoxicity and 40% experienced vestibulotoxicity in a delayed fashion up to 10 days posttreatment cessation (mean 3.9 ± 0.7). Therapeutic monitoring did not necessarily prevent delayed vestibulotoxicity. Nephrotoxicity was less common for SDD compared with MDD (60% vs. 35%, p = 0.01). However, the SDD group experienced vestibulotoxicity at a lower cumulative dose (6.3 vs. 7.0 g, p = 0.04) and shorter duration of therapy (20.7 vs 29.4 d, p = 0.02).

CONCLUSIONS

Our study further highlights important insights regarding gentamicin-induced vestibulotoxicity. While SDD is associated with decreased risk for nephrotoxicity compared with MDD, it confers a higher risk for vestibulotoxicity.

Determining the optimal antibiotic regimen for chorioamnionitis: A systematic review and meta-analysis

INTRODUCTION

To evaluate the effect of antibiotic regimens for chorioamnionitis on maternal and neonatal outcomes.

MATERIAL AND METHODS

We conducted a systematic review, wherein we searched six bibliographic databases until June 2020 and included randomized clinical trials describing antibiotic regimens for treating chorioamnionitis. Risk of bias was assessed using the Cochrane Risk of Bias tool V2.0. Random-effects meta-analysis was performed and results were presented as risk ratio (RR) and mean differences (MD) with 95% CI.

RESULTS

Fourteen trials at low-to-high risk of bias were included. Three trials (n = 244), comparing different intrapartum antibiotic regimens, showed no difference in outcomes except for lower composite maternal morbidity (endometritis, pneumonia, sepsis, blood transfusion, and ileus) with ampicillin/sulbactam vs ampicillin/gentamicin in one study (0/43 vs 6/49, P = .03). Three trials (n = 295) comparing different doses of intrapartum antibiotics showed no differences in maternal and neonatal outcomes, although one study showed a shorter duration of antibiotic treatment in the experimental arm (4 mg/kg gentamicin q24h + 1200 mg clindamycin q12h) vs conventional arm (1.33 mg/kg gentamicin + 800 mg clindamycin q8h) (48.0 ± 36 hours vs 55.2 ± 48 hours, P = .04). Four trials (n = 484) comparing postpartum antibiotics vs no antibiotics showed no difference in outcomes except for a shorter hospital stay (two studies, MD -7.90 hours, 95% CI -13.52 to -2.27 hours). Three trials (n = 447) comparing single vs multiple doses of postpartum antibiotics showed shorter hospital stay [MD -19.14 hours, 95% CI -29.88 to -8.41 hours), but no differences in treatment failure (RR 1.73, 95% CI 0.69-4.30) or total antibiotic dose (MD -9.24, 95% CI -19.49 to 1.01). One trial (n = 48) comparing intrapartum vs postpartum initiation of treatment found benefits to intrapartum (vs postpartum) initiation of antibiotics, in terms of postpartum maternal hospital stay (MD -24 hours, 95% CI -45.56 to -1.44 hours), neonatal hospital stay (MD -45.6 hours, -93.84 to -11.76 hours), and neonatal pneumonia or sepsis (RR 0.06, 95% CI 0.00-0.95).

CONCLUSIONS

Upon diagnosis of chorioamnionitis, there is limited evidence to recommend the prompt initiation of intrapartum antibiotics, and to consider a single dose of postpartum antibiotics over multiple doses or no treatment. Well-designed trials using standard definitions of chorioamnionitis, outcome measures, and newer antibiotics are required to inform clinical practice with regard to the preferred antibiotic regimen, dose, and duration to optimize maternal and neonatal outcomes.

Management of clinical chorioamnionitis: an evidence-based approach

This review aimed to examine the existing evidence about interventions proposed for the treatment of clinical chorioamnionitis, with the goal of developing an evidence-based contemporary approach for the management of this condition. Most trials that assessed the use of antibiotics in clinical chorioamnionitis included patients with a gestational age of ≥34 weeks and in labor. The first-line antimicrobial regimen for the treatment of clinical chorioamnionitis is ampicillin combined with gentamicin, which should be initiated during the intrapartum period. In the event of a cesarean delivery, patients should receive clindamycin at the time of umbilical cord clamping. The administration of additional antibiotic therapy does not appear to be necessary after vaginal or cesarean delivery. However, if postdelivery antibiotics are prescribed, there is support for the administration of an additional dose. Patients can receive antipyretic agents, mainly acetaminophen, even though there is no clear evidence of their benefits. Current evidence suggests that the administration of antenatal corticosteroids for fetal lung maturation and of magnesium sulfate for fetal neuroprotection to patients with clinical chorioamnionitis between 24 0/7 and 33 6/7 weeks of gestation, and possibly between 23 0/7 and 23 6/7 weeks of gestation, has an overall beneficial effect on the infant. However, delivery should not be delayed to complete the full course of corticosteroids and magnesium sulfate. Once the diagnosis of clinical chorioamnionitis has been established, delivery should be considered, regardless of the gestational age. Vaginal delivery is the safer option and cesarean delivery should be reserved for standard obstetrical indications. The time interval between the diagnosis of clinical chorioamnionitis and delivery is not related to most adverse maternal and neonatal outcomes. Patients may require a higher dose of oxytocin to achieve adequate uterine activity or greater uterine activity to effect a given change in cervical dilation. The benefit of using continuous electronic fetal heart rate monitoring in these patients is unclear. We identified the following promising interventions for the management of clinical chorioamnionitis: (1) an antibiotic regimen including ceftriaxone, clarithromycin, and metronidazole that provides coverage against the most commonly identified microorganisms in patients with clinical chorioamnionitis; (2) vaginal cleansing with antiseptic solutions before cesarean delivery with the aim of decreasing the risk of endometritis and, possibly, postoperative wound infection; and (3) antenatal administration of N-acetylcysteine, an antioxidant and antiinflammatory agent, to reduce neonatal morbidity and mortality. Well-powered randomized controlled trials are needed to assess these interventions in patients with clinical chorioamnionitis.

Daily gentamicin using ideal body weight demonstrates lower risk of postpartum endometritis and increased chance of successful outcome compared with traditional 8-hour dosing for the treatment of intrapartum chorioamnionitis

Background: Clinical chorioamnionitis complicates approximately 1-4% of pregnancies overall. Although universal agreement does not exist regarding the antibiotic regimen of choice, most studies have evaluated intravenous ampicillin dosed at 2 g every 6 hours plus gentamicin dosed every 8 hours. Only three studies have examined daily gentamicin for the treatment of intrapartum chorioamnionitis and thus is insufficiently investigated. Objective: This study seeks to determine whether daily dosing of gentamicin using ideal body weight for the treatment of intrapartum chorioamnionitis is more or equivalently efficacious when compared to traditional 8-hour dosing regimens. Materials and methods: We conducted a retrospective cohort study and reviewed charts on all women receiving treatment for intrapartum chorioamnionitis, which included intravenous gentamicin daily dosing calculated using 5 mg/kg ideal body weight or receiving traditional every 8 hours dosing of gentamicin at two large academic centers. Our primary outcomes were resolution of infection following delivery without the development of maternal endometritis and/or neonatal sepsis. Baseline characteristics were compared between dosing groups using Welch two-sample t-tests for continuous variables, uncorrected X² test and exact binomial 95% confidence intervals. We calculated the risk ratios of each outcome in the ideal versus traditional dosing groups using modified Poisson regression, both crude and adjusted. Adjusted models were controlled for variables determined to be potential confounders, which included BMI, diabetes mellitus, gestational blood pressure >140/90, group β-Streptococcus status, race, advanced maternal age (>34 y), and parity. Results: The study included 500 patients with 255 patients receiving daily dosing of gentamicin and 245 receiving traditional dosing of gentamicin. Of the patients receiving daily gentamicin compared to traditional dosing, 95.7% (95% CI 94.9-96.6%) achieved the primary outcome versus 92% (95% CI 90.8 - 93.2%), 2.4% (95% CI 1.8-3%) developed endometritis versus 5.6% (4.5-6.7%), 1.6% (95% CI 1.1-2.1%) delivered neonates with sepsis versus 3.3% (CI 2.5-4.1%), and 36.9% required cesarean delivery versus 41.4%. In crude analysis, compared to traditional dosing, IDW daily dosing was associated with a lower risk of postpartum endometritis (RR 0.42, 95% CI 0.16-1.10, p = .032). After adjusting for BMI, diabetes mellitus, gestational blood pressure >140/90, group β-Streptococcus status, race, advanced maternal age (>34 y), and parity, the IDW daily dosing group had a 5% greater chance of successful outcome (RR 1.05, 95% CI 1.00-1.10, p = .046) and a 64% lower risk of endometritis (RR 0.35, 95% CI 0.15-0.83, p = .017). Conclusion: Daily dosing of gentamicin using ideal body weight is associated with a lower risk of postpartum endometritis and high chance of a successful outcome in the treatment of intrapartum chorioamnionitis compared with traditional 8-hour dosing in our ethnically diverse, urban population and thus may be considered a superior option to every 8 hours dosing regimens.

Surgical site infections after cesarean delivery: epidemiology, prevention and treatment

Cesarean delivery (CD) is one of the most common procedures performed in the United States, accounting for 32% of all deliveries. Postpartum surgical site infection (SSI), wound infection and endometritis is a major cause of prolonged hospital stay and poses a burden to the health care system. SSIs complicate a significant number of patients who undergo CD - 2-7% will experience sound infections and 2-16% will develop endometritis. Many risk factors for SSI have been described. These include maternal factors (such as tobacco use; limited prenatal care; obesity; corticosteroid use; nulliparity; twin gestations; and previous CD), intrapartum and operative factors (such as chorioamnionitis; premature rupture of membranes; prolonged rupture of membranes; prolonged labor, particularly prolonged second stage; large incision length; subcutaneous tissue thickness > 3 cm; subcutaneous hematoma; lack of antibiotic prophylaxis; emergency delivery; and excessive blood loss), and obstetrical care on the teaching service of an academic institution. Effective interventions to decrease surgical site infection include prophylactic antibiotic use (preoperative first generation cephalosporin and intravenous azithromycin), chlorhexidine skin preparation instead of iodine, hair removal using clippers instead of razors, vaginal cleansing by povidone-iodine, placental removal by traction of the umbilical cord instead of by manual removal, suture closure of subcutaneous tissue if the wound thickness is >2 cm, and skin closure with sutures instead of with staples. Implementation of surgical bundles in non-obstetric patients has been promising., Creating a similar patient care bundle comprised evidence-based elements in patients who undergo CD may decrease the incidence of this major complication. Each hospital has the opportunity to create its own CD surgical bundle to decrease surgical site infection.

Daily dosing of gentamicin using ideal body weight for the treatment of intrapartum chorioamnionitis: a pilot study

PURPOSE

This study aimed to determine whether daily dosing of gentamicin using ideal body weight in the treatment of chorioamnionitis is effective.

MATERIALS AND METHODS

We conducted a prospective observational study and followed all women receiving treatment for chorioamnionitis which included gentamicin daily dosing calculated using 5 mg/kg ideal body weight. Patients were excluded if pathological analysis of placenta did not confirm chorioamnionitis. Our primary outcome was resolution of infection following delivery without the development of maternal endometritis and/or neonatal sepsis. Ninety-five percent confidence intervals for proportions were calculated using exact binomial tests. These patients were retrospectively compared to patients who received treatment for chorioamnionitis which included traditional gentamicin every 8 h.

RESULTS

The study included 160 patients. Of the patients receiving daily dosing (n = 80) compared to traditional dosing (n = 80), 96% (95% CI 95.7-97.6%) achieved the primary outcome versus 91% (88.9-93.1%), 2.5% (95% CI 1.2-3.8%) developed endometritis versus 6.3% (4.2-8.4%), 1.3% (95% CI 0.4-2.2%) delivered neonates with sepsis versus 2.5% (1.2-3.8%), and 39% required cesarean delivery (95% CI 46.2-53.8) versus 37% (33.2-40.8%).

CONCLUSION

Daily dosing of gentamicin using ideal body weight is effective in successful treatment of chorioamnionitis without development endometritis and/or neonatal sepsis across different ethnicities.

Antibiotic regimens for postpartum endometritis

BACKGROUND

Postpartum endometritis occurs when vaginal organisms invade the endometrial cavity during the labor process and cause infection. This is more common following cesarean birth. The condition warrants antibiotic treatment.

OBJECTIVES

Systematically, to review treatment failure and other complications of different antibiotic regimens for postpartum endometritis.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 November 2014) and reference lists of retrieved studies.

SELECTION CRITERIA

We included randomized trials of different antibiotic regimens after cesarean birth or vaginal birth; no quasi-randomized trials were included.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy.

MAIN RESULTS

The review includes a total of 42 trials, and 40 of these trials contributed data on 4240 participants.Regarding the primary outcomes, seven studies compared clindamycin plus an aminoglycoside versus penicillins and showed fewer treatment failures (risk ratio (RR) 0.65, 95% confidence interval (CI) 0.46 to 0.90). There were more treatment failures in those treated with an aminoglycoside plus penicillin when compared to those treated with gentamycin/clindamycin (RR 2.57, 95% CI 1.48 to 4.46). There were more treatment failures (RR 1.66, 95% CI 1.01 to 2.74) and wound infections (RR 1.88, 95% CI 1.08 to 3.28) in those treated with second or third generation cephalosporins (excluding cephamycins) versus those treated with clindamycin plus gentamycin. In four studies comparing once-daily with thrice-daily dosing of gentamicin, there were fewer failures with once-daily dosing. There were more treatment failures (RR 1.94, 95% CI 1.38 to 2.72) and wound infections (RR 1.88, 95% CI 1.17 to 3.02) in those treated with a regimen with poor activity against penicillin-resistant anaerobic bacteria as compared to those treated with a regimen with good activity against penicillin-resistant anaerobic bacteria. There were no differences between groups with respect to severe complications and no trials reported any maternal deaths.Regarding the secondary outcomes, three studies that compared continued oral antibiotic therapy after intravenous therapy with no oral therapy, found no differences in recurrent endometritis or other outcomes. Four trials that compared clindamycin plus aminoglycoside versus cephalosporins identified fewer wound infections in those treated with clindamycin plus an aminoglycoside (RR 0.53, 95% CI 0.30 to 0.93). There were no differences between groups for the outcomes of allergic reactions. The overall risk of bias was unclear in the most of the studies. The quality of the evidence using GRADE comparing clindamycin and an aminoglycoside with another regimen (compared with cephalosporins or penicillins) was low to very low for therapeutic failure, severe complications, wound infection and allergic reaction.

AUTHORS' CONCLUSIONS

The combination of clindamycin and gentamicin is appropriate for the treatment of endometritis. Regimens with good activity against penicillin-resistant anaerobic bacteria are better than those with poor activity against penicillin-resistant anaerobic bacteria. There is no evidence that any one regimen is associated with fewer side-effects. Following clinical improvement of uncomplicated endometritis which has been treated with intravenous therapy, the use of additional oral therapy has not been proven to be beneficial.

Antibiotic regimens for management of intra-amniotic infection

BACKGROUND

Chorioamnionitis is a common infection that affects both mother and infant. Infant complications associated with chorioamnionitis include early neonatal sepsis, pneumonia, and meningitis. Chorioamnionitis can also result in maternal morbidity such as pelvic infection and septic shock.Clinical chorioamnionitis is estimated to occur in 1% to 2% of term births and in 5% to 10% of preterm births; histologic chorioamnionitis is found in nearly 20% of term births and in 50% of preterm births. Women with chorioamnionitis have a two to three times higher risk for cesarean delivery and a three to four times greater risk for endomyometritis, wound infection, pelvic abscess, bacteremia, and postpartum hemorrhage.

OBJECTIVES

To assess the effects of administering antibiotic regimens for intra-amniotic infection on maternal and perinatal morbidity and mortality and on infection-related complications.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (1 October 2014), CENTRAL, MEDLINE, Embase, LILACS, and the WHO ICTRP (September 2014). We also searched reference lists of retrieved studies and contacted experts in the field.

SELECTION CRITERIA

Randomized controlled trials (RCTs) that included women who experienced intra-amniotic infection. Trials were included if they compared antibiotic treatment with placebo or no treatment (if applicable), treatment with different antibiotic regimens, or timing of antibiotic therapy (intrapartum and/or postpartum). Therefore, this review assesses trials evaluating intrapartum antibiotics, intrapartum and postpartum antibiotic regimens, and postpartum antibiotics. Diagnosis of intra-amniotic infection was based on standard criteria (clinical/test), and no limit was placed on gestational age.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and trial quality. Two review authors independently extracted data and checked them for accuracy. We assessed the quality of the evidence using the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) approach and included a 'Summary of findings' table.

MAIN RESULTS

Our prespecified primary outcomes were maternal and neonatal mortality, maternal and neonatal severe infection, and duration of maternal and neonatal hospital stay.We included 11 studies (involving 1296 women) and assessed them as having low to moderate risk of bias - mainly because allocation concealment methods were not adequately reported, most studies were open, and outcome reporting was incomplete. The quality of the evidence was low to very low for most outcomes, as per the GRADE approach. The following antibiotics were assessed in the included trials: ampicillin, ampicillin/sulbactam, gentamicin, clindamycin, and cefotetan. During labor: meta-analysis of two studies found no clear differences in rates of neonatal sepsis (163 neonates; risk ratio (RR) 1.07, 95% confidence interval (CI) 0.40 to 2.86; I² = 9%; low quality of evidence), treatment failure (endometritis) (163 participants; RR 0.86, 95% CI 0.27 to 2.70; I² = 0%; low quality of evidence), and postpartum hemorrhage (RR 1.39, 95% CI 0.76 to 2.56; I² = 0%; low quality of evidence) when two different dosages/regimens of gentamicin were assessed. No clear differences between groups were found for any reported maternal or neonatal outcomes. The review did not identify data for a comparison of antibiotics versus no treatment/placebo. Postpartum: meta-analysis of two studies that evaluated use of antibiotics versus placebo after vaginal delivery showed no significant differences between groups in rates of treatment failure or postpartum endometritis. No significant differences were found in rates of neonatal death and postpartum endometritis when use of antibiotics was compared with no treatment. Four trials assessing two different dosages/regimens of gentamicin or dual-agent therapy versus triple-agent therapy, or comparing antibiotics, found no significant differences in most reported neonatal or maternal outcomes; the duration of hospital stay showed a difference in favor of the group of women who received short-duration antibiotics (one study, 292 women; mean difference (MD) -0.90 days, 95% CI -1.64 to -0.16; moderate quality of evidence). Intrapartum versus postpartum: one small study (45 women) evaluating use of ampicillin/gentamicin during intrapartum versus immediate postpartum treatment found significant differences favoring the intrapartum group in the mean number of days of maternal postpartum hospital stay (one trial, 45 women; MD -1.00 days, 95% CI -1.94 to - 0.06; very low quality of evidence) and the mean number of neonatal hospital stay days (one trial, 45 neonates; MD -1.90 days, 95% CI -3.91 to -0.49; very low quality of evidence). Although no significant differences were found in the rate of maternal bacteremia or early neonatal sepsis, for the outcome of neonatal pneumonia or sepsis we observed a significant difference favoring intrapartum treatment (one trial, 45 neonates; RR 0.06, 95% CI 0.00 to 0.95; very low quality of evidence).

AUTHORS' CONCLUSIONS

This review included 11 studies (having low to moderate risk of bias). The quality of the evidence was low to very low for most outcomes, as per the GRADE approach. Only one outcome (duration of hospital stay) was considered to provide moderate quality of evidence when antibiotics (short duration) were compared with antibiotics (long duration) during postpartum management of intra-amniotic infection. Our main reasons for downgrading the quality of evidence were limitations in study design or execution (risk of bias), imprecision, and inconsistency of results.Currently, limited evidence is available to reveal the most appropriate antimicrobial regimen for the treatment of patients with intra-amniotic infection; whether antibiotics should be continued during the postpartum period; and which antibiotic regimen or what treatment duration should be used. Also, no evidence was found on adverse effects of the intervention (not reported in any of the included studies). One small RCT showed that use of antibiotics during the intrapartum period is superior to their use during the postpartum period in reducing the number of days of maternal and neonatal hospital stay.

Update on new medicinal applications of gentamicin: evidence-based review

Gentamicin (GM) was discovered in 1963 and was introduced into parenteral usage in 1971. Since then, GM has been widely used in medicinal applications. The Food and Drug Administration of the United States approved the routine prescription of GM to treat the following infectious disorders: infection due to Klebsiella pneumoniae, Escherichia coli, Serratia marcescens, Citrobacter spp., Enterobacteriaceae spp., Pseudomonas spp.; Staphylococcus infectious disease; bacterial meningitis; bacterial sepsis of newborns; bacterial septicemia; infection of the eye, bone, skin and/or subcutaneous tissue; infective endocarditis; peritoneal dialysis-associated peritonitis due to Pseudomonas and other gram-negative organisms; peritonitis due to gastrointestinal tract infections; respiratory tract infections; and urinary tract infectious disease. GM is an old antibiotic and is used widely beyond its FDA-labeled indications as follows: actinomycotic infection; Staphylococcus saprophyticus bacteremia with pyelonephritis; appendicitis; cystic fibrosis; diverticulitis; adjunct regimen for febrile neutropenia; female genital infection; uterine infection; postnatal infection; necrotizing enterocolitis in fetus or newborn; osteomyelitis; pelvic inflammatory disease; plague; gonorrhea; tularemia; prophylaxis of post-cholecystectomy infection, transrectal prostate biopsy, and post-tympanostomy-related infection; malignant otitis externa; and intratympanically or transtympanically for Ménière's disease. GM is also used in combination regimens, such as with beta-lactam antibiotics to treat mixed infection and with bacteriophage to treat Staphylococcus aureus infections. It is also added to medical materials, such as GM-loaded cement spacers for osteomyelitis and prosthetic joint-associated infections. Overall, there are many medicinal applications for GM. To reduce the development of GM-resistant bacteria and to maintain its effectiveness, GM should be used only to treat or prevent infections that are proven or strongly suspected as being caused by susceptible bacteria. In the future, we believe that GM will be used more widely in combination therapy and applied to medical materials for clinical applications. A definitive, appropriately powered study of this antibiotic and its clinical applications is now required, especially in terms of its effectiveness, safety, and cost.

Evidence for the clinical management of chorioamnionitis

Acute chorioamnionitis or intra-amniotic infection is defined by maternal fever in association with at least one additional clinical criterion including maternal or fetal tachycardia, maternal leukocytosis, uterine tenderness, or foul amniotic fluid odor. In clinically uncertain cases, the diagnosis can be augmented by routine laboratory studies (e.g. white blood cell count and differential count and acute phase reactants) and assays done on amniotic fluid. In general, the clinical management of chorioamnionitis is based on observational or cohort studies; only a few randomized controlled trials have been done. Prompt administration of antibiotics and delivery decrease maternal and neonatal morbidity. The most commonly used antibiotic regimen is ampicillin and gentamicin. Recent evidence supports daily rather than three-times-daily dosing of gentamicin for greater efficacy and decreased fetal toxicity. There is no evidence demonstrating harm with the administration of corticosteroids (to promote fetal lung maturity) in women with acute chorioamnionitis. Cesarean delivery should be reserved for standard obstetric indications.

Once-daily dosing of gentamicin in obstetrics and gynecology

Gentamicin, an aminoglycoside with broad antimicrobial activity, is commonly used in both obstetrics and gynecology. Traditional dosing regimens for gentamicin have called for 3 times daily dosing, but recent insights into the pharmacodynamics of the drug have led to multiple studies of once-daily dosing regimens. Many studies have demonstrated efficacy, safety, and economy of the 24-hour dosing interval, resulting in recommendations that this become the standard for aminoglycoside administration. However, because of the unique considerations for drug administration in pregnant and postpartum women, the once-daily dosing regimens have not been widely adopted. Additional studies in pregnant and postpartum women have demonstrated therapeutic noninferiority, no increase in adverse events, and significant cost savings with once-daily dosing versus 3 times daily dosing of gentamicin. We review the literature and present rationale based on multiple controlled studies supporting single-daily dosing of gentamicin, 5 mg/kg/d actual body weight, for many common obstetrics-gynecology infections.

High compared with standard gentamicin dosing for chorioamnionitis: a comparison of maternal and fetal serum drug levels

OBJECTIVE

To compare umbilical cord and maternal serum peak gentamicin concentration, gentamicin elimination, and clinical outcomes between women who received once-daily compared with standard, thrice-daily dosing for clinical chorioamnionitis.

METHODS

We randomly assigned 38 laboring women, at least 34 weeks gestation, with clinical chorioamnionitis, into 1 of 2 gentamicin dosing groups: 5.1 mg/kg every 24 hours (once-daily; n = 18), or 120 mg followed by 80 mg every 8 hours (standard; n = 20). We measured maternal serum peak and delivery gentamicin concentrations and cord serum levels at delivery. Polynomial curve fitting was used to summarize gentamicin elimination. We also compared maternal and neonatal outcomes.

RESULTS

Demographic characteristics of the 2 groups were similar. Median maternal peak gentamicin levels were higher with once-daily (18.2 microg/mL) compared with standard dosing (7.1 microg/mL) (P < .001). Maternal serum levels decreased below 2 microg/mL by 10 hours in the once-daily group and by 5 hours in the standard dosing group. Extrapolated peak cord serum levels were 6.9 microg/mL in the once-daily and 2.9 microg/mL in the standard dosing arm. Cord levels decreased below 2 microg/mL by 10 hours in the once-daily and by 5 hours in the standard dosing group. We found no differences in maternal or neonatal outcomes.

CONCLUSION

Peak maternal serum gentamicin levels ranged from 13 to 25 microg/mL after a dose of 5.1 mg/kg. Single-dose gentamicin resulted in fetal serum peak levels that were closer to optimal neonatal values. Gentamicin clearance in the term fetus was similar to published values for the newborn infant. No adverse effects of high-dose therapy were noted.

Chemoprophylactic and bactericidal efficacy of 80 mg gentamicin in a single and once-daily dosing

OBJECTIVE

The objective was to examine the biodistribution, the chemoprophylactic, and the bactericide efficacy of 80-mg gentamicin single or once-daily dosing.

STUDY DESIGN

Ninety-six patients who had had cesarean section or gynecological surgery received 80 mg gentamicin for chemoprophylaxis. A second group of 92 patients with Gram-negative infection received once-daily 80-mg gentamicin intramuscularly, combined with cefoxitin or ceforanide, for 5 days. Gentamicin serum and tissue concentration was determined 1 h after the first administration.

RESULTS

The chemoprophylactic efficacy of gentamicin was 93.7%. The treatment efficacy was high in patients with chorioamnionitis and endometritis (92.9%), moderate in those with wound infection (69.5%), and less effective in those with septicemia (55.6%). Twenty-six percent of patients continued with antibiotics for infection control. The mean serum level was 4.48+/-0.49 and 5.56+/-0.66 microg/ml in obstetrical and gynecological patients respectively (p>0.05). Serum levels >4 microg/ml were achieved in 91% of patients.

CONCLUSIONS

A single dose of 80 mg gentamicin offers chemoprophylaxis and achieves therapeutic serum-concentrations 1 h after administration. The 5-day combination of once-daily 80 mg gentamicin with a second-generation cephalosporin is effective in patients with chorioamnionitis and endometritis, but only moderately effective in those with wound infections and septicemia.

Antibiotic regimens for endometritis after delivery

BACKGROUND

Postpartum endometritis, which is more common after cesarean section, occurs when vaginal organisms invade the endometrial cavity during labor and birth. Antibiotic treatment is warranted.

OBJECTIVES

The effect of different antibiotic regimens for the treatment of postpartum endometritis on failure of therapy and complications was systematically reviewed.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's trials register (30 January 2004).

SELECTION CRITERIA

Randomized trials of different antibiotic regimens for postpartum endometritis, after cesarean section or vaginal birth, where outcomes of treatment failure or complications were reported were selected.

DATA COLLECTION AND ANALYSIS

We abstracted data independently and made comparisons between different types of antibiotic regimen based on type of antibiotic and duration and route of administration. Summary relative risks were calculated.

MAIN RESULTS

Thirty-eight trials with 3983 participants were included. Fifteen studies comparing clindamycin and an aminoglycoside with another regimen showed more treatment failures with the other regimen (relative risk (RR) 1.44; 95% confidence interval (CI) 1.15 to 1.80). Failures of those regimens with poor activity against penicillin resistant anaerobic bacteria were more likely (RR 1.94; 95% CI 1.38 to 2.72). In three studies that compared continued oral antibiotic therapy after intravenous therapy with no oral therapy, no differences were found in recurrent endometritis or other outcomes. In four studies comparing once daily with thrice daily dosing of gentamicin there were fewer failures with once daily dosing. There was no evidence of difference in incidence of allergic reactions. Cephalosporins were associated with less diarrhea.

REVIEWERS' CONCLUSIONS

The combination of gentamicin and clindamycin is appropriate for the treatment of endometritis. Regimens with activity against penicillin- resistant anaerobic bacteria are better than those without. There is no evidence that any one regimen is associated with fewer side effects. Once uncomplicated endometritis has clinically improved with intravenous therapy, oral therapy is not needed.

Pharmacodynamics and dosing of aminoglycosides

Aminoglycosides are concentration-dependent killing agents whose pharmacodynamic predictors of efficacy are the area-under-the-curve to minimum inhibitory concentration ratio and the peak to minimum inhibitory concentration ratio. Prospective studies have shown that these agents can be given once-daily or less frequently in most clinical settings, with equal efficacy and possible reduced toxicity. Dosages for different clinical settings have been studied and methods are available to monitor once-daily dosing.

Postpartum infection treatments: a review

Upper genital tract infections are the most common complications of the puerperium. Less frequent complications are mastitis and septic pelvic thrombophlebitis. Several risk factors including obstetrical, gynaecological, demographic and surgical, are associated with an increased rate of postpartum endometritis and their influence is higher after a caesarean than vaginal delivery. Postpartum endometritis rate range from 15 to 35%. Their identification should be prioritized to prevent this complication. The vaginal flora plays a central role in the development of endometritis. Prophylactic antibiotic treatment at the time of caesarean delivery has helped reduce the rate of postpartum endometritis. When endometritis has been identified and cultures from the genital tract obtained. empirical therapy should be instituted until culture results are available and only then, if needed, therapy changed according to the microorganism's sensitivity. The use of penicillins, cephalosporins, aminoglycosides, metronidazole, macrolides, beta-lactamases inhibitors and quinolones has been reviewed. Various available therapies for endometritis and the experience and results of several authors were analysed. Cost-effectiveness is one of the most important aspects in the decision making process in searching for the best therapy. The monitoring of infection rates within each institution to determine the effectiveness of the prophylactic agent to be used is imperative; it would reduce costs and at the same time, provide the best adequate therapy. After reviewing all the aspects of the different therapies used in case of postpartum endometritis, it may be concluded that the combination of clindamycin and gentamicin is preferred as it can be administered once-daily, and is also the least expensive. Other issues to be taken into account are the number of daily doses and duration of therapy, factors that affect patients compliance and cost of hospitalisation.

Gentamicin and clindamycin therapy in postpartum endometritis: the efficacy of daily dosing versus dosing every 8 hours

OBJECTIVE

The objective of the study was to evaluate the efficacy of gentamicin and clindamycin given once daily versus the more common 8-hour dosing regimen for the treatment of postpartum endometritis.

STUDY DESIGN

In a prospective, placebo-controlled, double-blinded study, patients who had postpartum endometritis diagnosed were randomly selected to receive 1.5 mg/kg gentamicin and 900 mg clindamycin phosphate administered every 8 hours versus gentamicin 5 mg/kg and clindamycin phosphate 2700 mg administered as a single-daily dose. The single-dose group received an infusion of gentamicin and clindamycin, followed by an administration of intravenous placebo 8 and 16 hours later to maintain blinding. Treatment success was defined as absence of fever 72 hours after initiation of antibiotic therapy.

RESULTS

One hundred ten patients were enrolled. The daily-dose group (n = 55) and the thrice-daily dose group (n = 55) were similar with respect to age, gravidity, parity, gestational age, and maternal weight. Clinical characteristics (including maximum temperature, presence of predelivery chorioamnionitis, white blood cell count, and mode of delivery) were also similar. There was no difference in the mean time from initiation of therapy until becoming afebrile in the daily-dose group (27.4 +/- 24.9 hours) compared with the thrice-daily dose group (32.9 +/- 26.3 hours). Forty-five of 56 (82%) patients in the daily-dose group and 38 of 55 (69%) patients in the thrice-daily dose group had treatment success (P =.12).

CONCLUSION

Once-daily dosing with gentamicin and clindamycin in women with postpartum endometritis has a similar success rate as the standard every 8-hour dosing schedule.

Antibiotic regimens for management of intraamniotic infection

BACKGROUND

Intraamniotic infection is associated with maternal morbidity and neonatal sepsis, pneumonia and death. Although antibiotic treatment is accepted as the standard of care, few studies have been conducted to examine the effectiveness of different antibiotic regimens for this infection and whether to administer antibiotics intrapartum or postpartum.

OBJECTIVES

To study the effects of different maternal antibiotic regimens for intraamniotic infection on maternal and perinatal morbidity and mortality.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group trials register (May 2002) and the Cochrane Controlled Trials Register (The Cochrane Library, Issue 2, 2002).

SELECTION CRITERIA

Trials where there was a randomized comparison of different antibiotic regimens to treat women with a diagnosis of intraamniotic infection were included. The primary outcome was perinatal morbidity.

DATA COLLECTION AND ANALYSIS

Data were extracted from each publication independently by the authors.

MAIN RESULTS

Two eligible trials (181 women) were included in this review. No trials were identified that compared antibiotic treatment with no treatment. Intrapartum treatment with antibiotics for intraamniotic infection was associated with a reduction in neonatal sepsis (relative risk (RR) 0.08; 95% confidence interval (CI) 0.00, 1.44) and pneumonia (RR 0.15; CI 0.01, 2.92) compared with treatment given immediately postpartum, but these results did not reach statistical significance (number of women studied = 45). There was no difference in the incidence of maternal bacteremia (RR 2.19; CI 0.25, 19.48). There was no difference in the outcomes of neonatal sepsis (RR 2.16; CI 0.20, 23.21) or neonatal death (RR 0.72; CI 0.12, 4.16) between a regimen with and without anaerobic activity (number of women studied = 133). There was a trend towards a decrease in the incidence of post-partum endometritis in women who received treatment with ampicillin, gentamicin and clindamycin compared with ampicillin and gentamicin alone, but this did not reach statistical significance (RR 0.54; CI 0.19, 1.49).

REVIEWER'S CONCLUSIONS

The conclusions that can be drawn from this meta-analysis are limited due to the small number of studies. For none of the outcomes was a statistically significant difference seen between the different interventions. Current consensus is for the intrapartum administration of antibiotics when the diagnosis of intraamniotic infection is made; however, the results of this review neither support nor refute this although there was a trend towards improved neonatal outcomes when antibiotics were administered intrapartum. No recommendations can be made on the most appropriate antimicrobial regimen to choose to treat intraamniotic infection.

Antibiotic regimens for endometritis after delivery

BACKGROUND

Post-partum endometritis, which is more common after cesarean section, occurs when vaginal organisms invade the endometrial cavity during labour and birth. Antibiotic treatment is warranted.

OBJECTIVES

The effect of different antibiotic regimens for the treatment of postpartum endometritis on failure of therapy and complications was systematically reviewed.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's trials register and the Cochrane Controlled Trials Register. Date of last search: June 2001.

SELECTION CRITERIA

Randomised trials of different antibiotic regimens for postpartum endometritis, after cesarean section or vaginal birth, where outcomes of treatment failure or complications were reported were selected.

DATA COLLECTION AND ANALYSIS

Data were abstracted independently by the reviewers. Comparisons were made between different types of antibiotic regimen, based on type of antibiotic and duration and route of administration. Summary relative risks were calculated.

MAIN RESULTS

Forty-seven trials were included. Overall the studies were methodologically poor. In the intent-to-treat analysis, fifteen studies comparing clindamycin and an aminoglycoside with another regimen showed more treatment failures with another regimen (relative risk (RR) 1.32; 95% confidence interval (CI) 1.09-1.60). Failures of those regimens with poor activity against penicillin resistant anaerobic bacteria were more likely (RR 1.53; 95% CI 1.10-2.13). In four studies that compared continued oral antibiotic therapy after intravenous therapy, no differences were found in recurrent endometritis or other outcomes. There was no evidence of difference in incidence of allergic reactions. Cephalosporins were associated with less diarrhea.

REVIEWER'S CONCLUSIONS

The combination of gentamicin and clindamycin is appropriate for the treatment of endometritis. Regimens with activity against penicillin resistant anaerobic bacteria are better than those without. There is no evidence that any one regimen is associated with fewer side effects. Once uncomplicated endometritis has clinically improved with intravenous therapy, oral therapy is not needed.

Treatments for secondary postpartum haemorrhage

BACKGROUND

Secondary postpartum haemorrhage is any abnormal or excessive bleeding from the birth canal occurring between 24 hours and 12 weeks postnatally. In developed countries, two per cent of postnatal women are admitted to hospital with this condition, half of them undergoing uterine surgical evacuation; in developing countries it is a major contributor to maternal death.

OBJECTIVES

To evaluate the relative effectiveness and safety of the treatments used for secondary postpartum haemorrhage.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group trials register (May 2001), the Cochrane Controlled Trials Register (The Cochrane Library, issue 2, 2001), MEDLINE (back to 1966) and EMBASE (back to 1988). The National Research Register was also searched. The reference lists of trial reports and reviews were searched by hand. Where possible, further sources were sought from the first named authors of the papers identified.

SELECTION CRITERIA

All randomised or quasi randomised comparisons between drug therapies, surgical therapies and placebo or no treatment for the management of secondary postpartum haemorrhage occurring between 24 hours and three months following a pregnancy of at least 24 weeks gestation.

DATA COLLECTION AND ANALYSIS

Reports of possibly eligible studies were scrutinised by two investigators. The third investigator acted as an advisor/arbitrator.

MAIN RESULTS

Of the 45 papers identified, none met the inclusion criteria.

REVIEWER'S CONCLUSIONS

No information is available from randomised controlled trials to inform the management of women with secondary postpartum haemorrhage. This topic may have received little attention because it is perceived as being associated with maternal morbidity rather than mortality in developed countries; it is only recently that the extent and importance of postnatal maternal morbidity has been recognised. A well designed randomised controlled trial comparing the various drug therapies for women with secondary postpartum haemorrhage against each other and against placebo or no treatment groups is needed.

Gentamicin for the practicing urologist: review of efficacy, single daily dosing and "switch" therapy

PURPOSE

We review the literature on gentamicin, including single daily dosing and "switch" therapy.

MATERIALS AND METHODS

We used MEDLINE to search the literature from 1966 to June 1997, and then manually searched bibliographies to identify studies that our initial search might have missed.

RESULTS

Gentamicin has attractive characteristics, including wide spectrum, infrequent resistance, economy and familiarity. Although limited by well known toxicities, gentamicin remains a drug of choice for serious Gram-negative infections. Dosing strategies, such as single daily dosing and switch therapy, have renewed enthusiasm for this time-honored drug.

CONCLUSIONS

Gentamicin remains a valuable drug in urology. Once daily dosing and switch therapy offer the potential to increase effectiveness and convenience while decreasing toxicity and costs.

Single daily dosing of gentamicin: pharmacokinetic comparison of two dosing methodologies for postpartum endometritis

OBJECTIVE

We compared the pharmacokinetics of two methods for dosing gentamicin for the treatment of postpartum endometritis with the goal of achieving adequate peak serum concentrations (>12 mg/L) and prolonged trough levels below 2 mg/L.

METHODS

Group-I subjects (n = 5) received intravenous gentamicin, 5 mg/kg per total body weight over 60 min., with a maximum dose of 500 mg. Group-II subjects (n = 17) were dosed intravenously according to the following formula: Dose = desired peak concentration (fixed at 14 mg/L) * (volume of distribution, i.e., 0.35 L/kg) * adjusted body weight (in kilograms). Serum gentamicin levels were obtained 1 hr. and 8-12 hr. after infusion of the second dose. Pharmacokinetic parameters for the subjects in each group were calculated according to standard formulas.

RESULTS

Subjects in Group I had significantly higher doses and peak drug concentrations (P < 0.01), while in Group II, 76% of patients had peak levels less than desired (<12 mg/L). Both groups maintained trough levels of <2 mg/L in excess of 12 hr.

CONCLUSIONS

Changing to the adjusted body weight formula for Group I, while maintaining a dose between 4 and 5 mg/kg, would reduce excessive peak concentrations. Using a calculated volume of distribution of 0.4 L/kg in Group II would improve peak serum concentrations to the desired levels. Both dosing regimens ensure adequate aminoglycoside pharmacokinetic parameters and avoid the need for monitoring serial serum drug concentrations, provided the expected clinical response is also achieved. While the first dosing formula is simpler to calculate, the second dosing formula allows for more individualized dosing considerations.

Medication use during the perinatal period

OBJECTIVE

To briefly describe the drug therapy administered during the perinatal period of pregnancy for common maternal and fetal complications, and to identify those agents that should not be used for these conditions.

DATA SOURCES

References were obtained from an ongoing literature search of peer-reviewed obstetric and gynecologic journals and other selected medical and pharmacy journals available in the English language. Primary search vehicle was a weekly review of the tables of contents of nearly 1,300 medical journals provided by Reference Update (Institute of Scientific Information, Philadelphia). MEDLINE searches were also conducted using key terms for each subtopic.

STUDY SELECTION

Specific references were selected for each topic based on the adequacy of their study design, patient population, and a recent publication date. Reviews were used if a large number of primary references would have been required to adequately describe the topic.

DATA EXTRACTION

Most references reflected the current opinions expressed in the Educational (Technical) Bulletin and Committee Opinion series published by the American College of Obstetricians and Gynecologists. Recent, well-conducted studies that arrived at different conclusions were also included.

DATA SYNTHESIS

Data obtained from each reference reflected the conclusions of the authors based on their research or an analysis of the research on others on the appropriate use of the drug(s) for the specific condition being treated.

CONCLUSION

Drug therapy during the perinatal period is frequently required and can be beneficial for the mother, fetus, and newborn. Many complications previously associated with severe morbidity and mortality, such as infections, premature rupture of membranes, preterm labor, hypertension, maternal pain during labor, and postpartum hemorrhage, are now controlled with appropriate pharmacologic therapy. All health professionals who provide services to pregnant women should be knowledgeable in this drug therapy.

The pharmacokinetics of once-daily dosing with gentamicin in women with postpartum endometritis

OBJECTIVE

To evaluate the pharmacokinetics and cost of once-daily dosing with gentamicin in women with postpartum endometritis.

METHODS

Gentamicin in a single daily dose of 4.5 mg/kg was administered intravenously to 10 women with postpartum endometritis. Peak and trough gentamicin levels were measured, and nephrotoxicity and clinical ototoxicity were monitored. Pharmacokinetic data were analyzed, and a cost analysis of once-daily gentamicin administration was performed.

RESULTS

The mean elimination constant was 0.105 +/- 0.008 L/h, and the mean volume of distribution was 0.34 +/- 0.07 L/kg. Mean peak gentamicin levels exceeded 11 mg/L, and all trough levels were < 0.3 mg/L. Cost savings of 44% were achieved with once-daily dosing of gentamicin, compared with traditional thrice-daily dosing.

CONCLUSIONS

Once-daily dosing with gentamicin in women with postpartum endometritis achieves therapeutic peak levels without drug accumulation. Substantial cost savings are realized with this dosing regimen.