Background: Multidrug-resistant gram-negative (MDR GN) infections pose a significant threat to pediatric health. One of the treatment options in resource-limited settings is polymyxin-based combination therapy. However, evidence on the safety and clinical effectiveness of polymyxin B in children is scarce. Objectives: This study described the outcomes of mortality, bacteriologic cure and clinical response in pediatric patients with MDR GN infections treated with polymyxin-B-based combination therapy. Adverse drug events (ADE) are likewise described. Methodology: This is a retrospective descriptive study conducted at the Philippine General Hospital (PGH) among pediatric inpatients from December 2020 to June 2023 with MDR GN infections treated with polymyxin B (PmB), combined with at least one other antibiotic with gram-negative coverage for at least 48 hours. Frequency and rates of the outcomes were measured and analyzed, in relation to the bacterial groups (Enterobacterales, Acinetobacter spp., Pseudomonas aeruginosa) and combination antibiotic regimens used, i.e., meropenem- and fluoroquinolone-containing regimen (PmB+MEM vs PmB+FQ). Frequency of ADEs were measured. Results: A total of 172 cases in 136 patients were reviewed. The rates for 14-day mortality, failure in bacteriologic cure, and failure in clinical response were 26%, 15%, and 19%, respectively. In Enterobacterales infections, PmB+FQ demonstrated lower rates of mortality, failure in bacteriologic cure, and failure in clinical responses. On the other hand, in Acinetobacter infections, PmB+MEM numerically had lower rates for the same outcomes. The Pseudomonas group had conflicting data on which regimen is numerically more favorable overall. No statistically significant differences were found in the outcomes. ADEs noted were tubulopathy (5 cases), anaphylaxis (2 cases), and neurotoxicity (1 case). Conclusion Polymyxin-B-based combination therapy appears to be an acceptable treatment option for MDR GN infections in children, especially in settings where novel antibiotics are not accessible. Safety profiles indicate common but manageable adverse effects.
Polymyxin B ; Child

Objective:b> To assess the efficacy and safety of polymyxin B in neutropenic patients with hematologic disorders who had refractory gram-negative bacterial bloodstream infection. Methods:b> From August 2021 to July 2022, we retrospectively analyzed neutropenic patients with refractory gram-negative bacterial bloodstream infection who were treated with polymyxin B in the Department of Hematology of the First Affiliated Hospital of the Soochow University between August 2021 to July 2022. The cumulative response rate was then computed. Results:b> The study included 27 neutropenic patients with refractory gram-negative bacterial bloodstream infections. Polymyxin B therapy was effective in 22 of 27 patients. The median time between the onset of fever and the delivery of polymyxin B was 3 days [interquartile range (IQR) : 2-5]. The median duration of polymyxin B treatment was 7 days (IQR: 5-11). Polymyxin B therapy had a median antipyretic time of 37 h (IQR: 32-70). The incidence of acute renal dysfunction was 14.8% (four out of 27 cases), all classified as "injury" according to RIFLE criteria. The incidence of hyperpigmentation was 59.3%. Conclusion:b> Polymyxin B is a viable treatment option for granulocytopenia patients with refractory gram-negative bacterial bloodstream infections.
Humans ; Polymyxin B/adverse effects* ; Retrospective Studies ; Gram-Negative Bacterial Infections/complications* ; Fever/drug therapy* ; Sepsis/drug therapy* ; Anti-Bacterial Agents/therapeutic use* ; Bacteremia/complications*

Polymyxin B, which is a last-line antibiotic for extensively drug-resistant Gram-negative bacterial infections, became available in China in Dec. 2017. As dose adjustments are based solely on clinical experience of risk toxicity, treatment failure, and emergence of resistance, there is an urgent clinical need to perform therapeutic drug monitoring (TDM) to optimize the use of polymyxin B. It is thus necessary to standardize operating procedures to ensure the accuracy of TDM and provide evidence for their rational use. We report a consensus on TDM guidelines for polymyxin B, as endorsed by the Infection and Chemotherapy Committee of the Shanghai Medical Association and the Therapeutic Drug Monitoring Committee of the Chinese Pharmacological Society. The consensus panel was composed of clinicians, pharmacists, and microbiologists from different provinces in China and Australia who made recommendations regarding target concentrations, sample collection, reporting, and explanation of TDM results. The guidelines provide the first-ever consensus on conducting TDM of polymyxin B, and are intended to guide optimal clinical use.
Humans ; Anti-Bacterial Agents/therapeutic use* ; China ; Drug Monitoring/methods* ; Polymyxin B ; Practice Guidelines as Topic

OBJECTIVE: To observe the clinical efficacy and safety of polymyxin B sulfate in febrile neutropenia patients with hematonosis. METHODS: Clinical data of 50 patients in the department of hematology, Fujian Medical University Union Hospital from October 2019 to September 2020 were collected. All the patients developed febrile neutropenia after chemotherapy or hematopoietic stem cell transplantation. According to the results of drug susceptible test, polymyxin B sulfate was administrated mainly when the empirical antimicrobial treatments was poor and the pathogenic microbes test was positive. RESULTS: A total of 85 times of infection occurred in 50 patients. The infection sites were lung, blood flow, intestinal tract, oral cavity, perianal, soft tissue and nasal cavity. Gram negative bacteria was the main pathogenic microbe. After administration of polymyxin B sulfate when the etiology was confirmed, the total effective rate was 68%, especially the effective rate increased significantly after more than 7 days of polymyxin B sulfate treatment. Also, 24% and 8% of the patients were discharged automatically and died respectively. The effective rate of patients receiving carbapenem antibiotics changed to polymyxin B sulfate within 14 or 7 days was 80% and 70.6%, respectively, while the effective rate of patients who changed after 2 weeks was only 33.3%. The effective rate of patients receiving tigecycline changed to polymyxin B sulfate within 14 or 7 days was 80% and 66.7%, respectively. The incidence of adverse reactions of polymyxin B sulfate was low, most of which were mild, and only one patient occurred rhabdomyolysis. CONCLUSION Polymyxin B sulfate has good clinical efficacy and safety in febrile neutropenia patients with hematonosis.
Anti-Bacterial Agents/therapeutic use* ; Carbapenems ; Febrile Neutropenia/drug therapy* ; Humans ; Polymyxin B/therapeutic use* ; Tigecycline

The current strategy in treating multi-drug resistant gram-negative bacterial (MDR-GNB) infections is salvage therapy by using polymyxins. However, the beginning emergence of polymyxin resistance should enforce strict antimicrobial stewardship programs to preserve polymyxin efficacy. Knowledge of structural characteristics, pharmacodynamic, and pharmacokinetic profiles of polymyxins, as well as consideration of efficacy, safety, suitability, and cost, will help in the choice of the appropriate polymyxin for therapy. Polymyxin B is the recommended polymyxin for systemic use, while colistin is recommended for lower urinary tract infections, intraventricular, and intrathecal use. Either polymyxin can be used for hospital-acquired and ventilator-associated pneumonia. Combination therapy over monotherapy remains to be advantageous due to synergism and decreased resistance development. The choice of the second drug to be used should be based on full susceptibility, or if unavailable, a drug with the least minimum inhibitory concentration relative to the breakpoint set by the Clinical and Laboratory Standards Institute. Using the mnemonic ESCAPE can also guide physicians in their polymyxin prescription process: (1) Checking if the pathogen is Extensively resistant or multi-drug resistant; (2) checking the patient’s clinical status if compatible with Significant infection; (3) using Combination therapy; (4) ensuring Adequate dosing; (5) Proper preparation and administration of drug; and (6) keeping an Eye for response and adverse effects.
Polymyxin B ; Colistin ; Polymyxins

Allergic contact dermatitis is an inflammatory condition associated with periorbital erythema, edema, and pruritus. The periorbital skin is relatively thin compared with the skin over other facial areas; therefore, it is vulnerable to allergen penetration and may show a variety of cutaneous manifestations. Recently, vision enhancement surgery is a widely performed procedure, and the prevalence of senile cataract and glaucoma is increasing. The prevalence of periocular allergic contact dermatitis is increasing secondary to the growing use of topical ophthalmic medications. Several studies in Korea have reported periocular allergic contact dermatitis secondary to the use of topical ophthalmic medications including latanoprost (Latano®), fluorometholone (Tolon®), polymyxin B (Terramycin®), atropine sulfate (Atropine®), neomycin sulfate (Cambison®), and befunolol hydrochloride (Bentos®), among others. However, ofloxacin (Effexin®)-induced allergic contact dermatitis has not been reported in the domestic and/or foreign literature. We report a case of periocular allergic contact dermatitis secondary to the use of ofloxacin ophthalmic ointment.
Atropine ; Cataract ; Dermatitis, Allergic Contact* ; Edema ; Erythema ; Fluorometholone ; Glaucoma ; Korea ; Neomycin ; Ofloxacin* ; Polymyxin B ; Prevalence ; Pruritus ; Skin

Lipopolysaccharides (LPS) contamination in herbal crude polysaccharides is inevitable. The present study was performed to explore the effect of polymyxin B on abolishing the influence of LPS contamination in mononuclear cells. LPS was pretreated with polymyxin B sulfate (PB) at different concentrations for 1, 5 or 24 h, and then used to stimulate RAW264.7 and mouse peritoneal macrophages (MPMs). The nitric oxide (NO) and tumor necrosis factor-α (TNF-α) in cell culture supernatant, as the indications of cell response, were assayed. Bupleurum chinensis polysaccharides (BCPs) with trace amount contamination of LPS was treated with PB. 30 μg·mL of PB, treating LPS (10 and 1 000 ng·mL in stimulating RAW264.7 and MPMs respectively) at 37 °C for 24 h, successfully abolished the stimulating effect of LPS on the cells. When the cells were stimulated with LPS, BCPs further promoted NO production. However, pretreated with PB, BCPs showed a suppression of NO production in MPMs and no change in RAW264.7. In the in vitro experiments, LPS contamination in polysaccharide might bring a great interference in assessing the activity of drug. Pretreatment with PB (30 μg·mL) at 37 °C for 24 h was sufficient to abolish the effects of LPS contamination (10 and 1 000 ng·mL).
Animals ; Bupleurum ; chemistry ; Drug Contamination ; Drugs, Chinese Herbal ; analysis ; pharmacology ; Lipopolysaccharides ; analysis ; antagonists & inhibitors ; Macrophages ; drug effects ; metabolism ; Mice ; Nitric Oxide ; metabolism ; Polymyxin B ; analysis ; pharmacology ; Polysaccharides ; analysis ; pharmacology ; Tumor Necrosis Factor-alpha ; metabolism

Although shock in sepsis is usually managed successfully by conventional medical treatment, a subset of cases do not respond and may require salvage therapies such as veno-arterial extracorporeal membrane oxygenation (VA ECMO) support as well as an attempt to remove endotoxins. However, there are limited reports of attempts to remove endotoxins in patients with septic shock on VA ECMO support. We recently experienced a case of septic shock with severe myocardial injury whose hemodynamic improvement was unsatisfactory despite extracorporeal membrane oxygenation (ECMO) support. Since the cause of sepsis was acute pyelonephritis and blood cultures grew gram-negative bacilli, we additionally applied polymyxin B direct hemoperfusion (PMX-DHP) to the ECMO circuit and were able to successfully taper off vasopressors and wean off ECMO support. To the best of our knowledge, this is the first adult case in which PMX-DHP in addition to ECMO support was successfully utilized in a patient with septic shock. This case indicates that additional PMX-DHP therapy may be beneficial and technically feasible in patients with septic shock with severe myocardial injury refractory to ECMO support.
Adult ; Cardiomyopathies* ; Endotoxins ; Extracorporeal Membrane Oxygenation ; Hemodynamics ; Hemoperfusion* ; Humans ; Membranes* ; Oxygen* ; Polymyxin B* ; Polymyxins* ; Pyelonephritis ; Salvage Therapy ; Sepsis ; Shock ; Shock, Septic*

Although shock in sepsis is usually managed successfully by conventional medical treatment, a subset of cases do not respond and may require salvage therapies such as veno-arterial extracorporeal membrane oxygenation (VA ECMO) support as well as an attempt to remove endotoxins. However, there are limited reports of attempts to remove endotoxins in patients with septic shock on VA ECMO support. We recently experienced a case of septic shock with severe myocardial injury whose hemodynamic improvement was unsatisfactory despite extracorporeal membrane oxygenation (ECMO) support. Since the cause of sepsis was acute pyelonephritis and blood cultures grew gram-negative bacilli, we additionally applied polymyxin B direct hemoperfusion (PMX-DHP) to the ECMO circuit and were able to successfully taper off vasopressors and wean off ECMO support. To the best of our knowledge, this is the first adult case in which PMX-DHP in addition to ECMO support was successfully utilized in a patient with septic shock. This case indicates that additional PMX-DHP therapy may be beneficial and technically feasible in patients with septic shock with severe myocardial injury refractory to ECMO support.
Adult ; Cardiomyopathies ; Endotoxins ; Extracorporeal Membrane Oxygenation ; Hemodynamics ; Hemoperfusion ; Humans ; Membranes ; Oxygen ; Polymyxin B ; Polymyxins ; Pyelonephritis ; Salvage Therapy ; Sepsis ; Shock ; Shock, Septic

The effects of direct hemoperfusion with polymyxin B immobilized fiber (PMX) treatment for septic shock have been recently reported. However, little evidence of a true benefit on clinical outcomes, including mortality, is available. Herein, we report three cases of intra-abdominal infection associated with refractory septic shock Case 1 was Escherichia coli peritonitis after a colectomy. PMX treatment improved the hemodynamic parameters and lactic acid levels of the patient. In case 2, secondary peritonitis was associated with septic or cardiogenic shock. Septic cardiomyopathy was assumed to be the cause of shock. 24 hours after the use of PMX, cardiac contractility assessed by echocardiography returned to baseline. In case 3, a patient with Burkitt's lymphoma and neutropenia was found to be gastroenteritis and Klebsiella pneumoniae bacteremia. Intravenous meropenem was administered for 3 days. Hemodynamic parameters improve after the twice use of PMXOverall, the change of serial sequential organ failure assessment score (SOFA) was more significant in surgical cases as compared to the medical case at 72 hours after PMX administration. All patients were discharged from the hospital. In addition to early resuscitation efforts and infection source control, PMX treatment may be beneficial to patients with refractory intra-abdominal infection associated with septic shock.
Bacteremia ; Burkitt Lymphoma ; Cardiomyopathies ; Colectomy ; Echocardiography ; Escherichia coli ; Gastroenteritis ; Hemodynamics ; Hemoperfusion* ; Humans ; Intraabdominal Infections ; Klebsiella pneumoniae ; Lactic Acid ; Mortality ; Neutropenia ; Peritonitis ; Polymyxin B* ; Resuscitation ; Shock ; Shock, Cardiogenic ; Shock, Septic*