Browsing by Subject "Vancomycin"
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Item Evaluation of Vancomycin Dose Needed to Achieve 24-Hour Area Under the Concentration-Time Curve to Minimum Inhibitory Concentration Ratio Greater Than or Equal to 400 Using Pharmacometric Approaches in Pediatric Intensive Care Patients(Wolters Kluwer, 2024-10-01) Jung, Dawoon; Kishk, Omayma A.; Bhutta, Adnan T.; Cummings, Ginny E.; El Sahly, Hana M.; Virk, Manpreet K.; Moffett, Brady S.; Morris Daniel, Jennifer L.; Watanabe, Amy; Fishbane, Nicholas; Kotloff, Karen L.; Gu, Kenan; Ghazaryan, Varduhi; Gobburu, Jogarao V. S.; Akcan-Arikan, Ayse; Campbell, James D.; Pediatrics, School of MedicineObjectives: To investigate which independent factor(s) have an impact on the pharmacokinetics of vancomycin in critically ill children, develop an equation to predict the 24-hour area under the concentration-time curve from a trough concentration, and evaluate dosing regimens likely to achieve a 24-hour area under the concentration-time curve to minimum inhibitory concentration ratio (AUC24/MIC) greater than or equal to 400. Design: Prospective population pharmacokinetic study of vancomycin. Setting: Critically ill patients in quaternary care PICUs. Patients: Children 90 days old or older to younger than 18 years who received IV vancomycin treatment, irrespective of the indication for use, in the ICUs at the University of Maryland Children's Hospital and Texas Children's Hospital were enrolled. Interventions: Vancomycin was prescribed at doses and intervals chosen by the treating clinicians. Measurements and main results: A median of four serum levels of vancomycin per patient were collected along with other variables for up to 7 days following the first administration. These data were used to characterize vancomycin pharmacokinetics and evaluate the factors affecting the variability in achieving AUC24/MIC ratio greater than or equal to 400 in PICU patients who are not on extracorporeal therapy. A total of 302 children with a median age of 6.0 years were enrolled. A two-compartment model described the pharmacokinetics of vancomycin with the clearance of 2.76 L/hr for a typical patient weighing 20 kg. The glomerular filtration rate estimated using either the bedside Schwartz equation or the chronic kidney disease in children equation was the only statistically significant predictor of clearance among the variables evaluated, exhibiting equal predictive performance. The trough levels achieving AUC24/MIC = 400 were 5.6-10.0 μg/mL when MIC = 1 μg/mL. The target of AUC24/MIC greater than or equal to 400 was achieved in 60.4% and 36.5% with the typical dosing regimens of 15 mg/kg every 6 and 8 hours (q6h and q8h), respectively. Conclusions: The pharmacokinetics of vancomycin in critically ill children were dependent on the estimated glomerular filtration rate only. Trough concentrations accurately predict AUC24. Typical pediatric vancomycin dosing regimens of 15 mg/kg q6h and q8h will often lead to AUC24/MIC under 400.Item Halicin Is Effective Against Staphylococcus aureus Biofilms In Vitro(Wolters Kluwer, 2022) Higashihira, Shota; Simpson, Stefanie Jan; Collier, Christopher David; Natoli, Roman Michael; Kittaka, Mizuho; Greenfield, Edward Michael; Orthopaedic Surgery, School of MedicineBackground: Biofilms protect bacteria from the host immune system and many antibiotics, making the treatment of orthopaedic infections difficult. Halicin, a recently discovered antibiotic, has potent activity against nonorthopaedic infections in mice and the planktonic, free-living forms of many bacterial species, including Staphylococcus aureus , a common cause of orthopaedic infections. Importantly, halicin did not induce resistance in vitro and was effective against drug-resistant bacteria and proliferating and quiescent bacteria. Quiescence is an important cause of antibiotic tolerance in biofilms. However, whether halicin acts on biofilms has not been tested. Questions/purposes: (1) Does halicin reduce the viability of S. aureus in less mature and more mature biofilms as it does in planktonic cultures? (2) How do the relative effects of halicin on S. aureus biofilms and planktonic cultures compare with those of conventional antibiotics (tobramycin, cefazolin, vancomycin, or rifampicin) that are commonly used in clinical orthopaedic infections? Methods: To measure minimal biofilm eradication concentrations (MBECs) with less mature 3-day and more mature 7-day biofilms, we used 96-well peg plates that provided high throughput and excellent reproducibility. After S. aureus -Xen36 biofilm formation, planktonic bacteria were removed from the cultures, and the biofilms were exposed to various concentrations of halicin, tobramycin, cefazolin, vancomycin, or rifampicin for 20 hours. Biofilm viability was determined by measuring resazurin reduction or by counting colony-forming units after sonication. To determine effects of halicin and the conventional antibiotics on biofilm viability, we defined MBEC 75 as the lowest concentration that decreased viability by 75% or more. To determine effects on bacterial viability in planktonic cultures, minimum inhibitory concentrations (MICs) were determined with the broth dilution method. Each result was measured in four to 10 independent experiments. Results: We found no differences between halicin's effectiveness against planktonic S. aureus and 3-day biofilms (MIC and MBEC 75 for 3-day biofilms was 25 μM [interquartile range 25 to 25 and 25 to 25, respectively]; p > 0.99). Halicin was eightfold less effective against more mature 7-day biofilms (MBEC 75 = 200 μM [100 to 200]; p < 0.001). Similarly, tobramycin was equally effective against planktonic culture and 3-day biofilms (MIC and MBEC 75 for 3-day biofilms was 20 μM [20 to 20 and 10 to 20, respectively]; p > 0.99). Tobramycin's MBEC 75 against more mature 7-day biofilms was 320 μM (320 to 480), which is 16-fold greater than its planktonic MIC (p = 0.03). In contrast, the MBEC 75 for cefazolin, vancomycin, and rifampicin against more mature 7-day biofilms were more than 1000-fold (> 1000; p < 0.001), 500-fold (500 to 875; p < 0.001), and 3125-fold (3125 to 5469; p = 0.004) greater than their planktonic MICs, respectively, consistent with those antibiotics' relative inactivity against biofilms. Conclusion: Halicin was as effective against S. aureus in less mature 3-day biofilms as those in planktonic cultures, but eightfold higher concentrations were needed for more mature 7-day biofilms. Tobramycin, an antibiotic whose effectiveness depends on biofilm maturity, was also as effective against S. aureus in less mature 3-day biofilms as those in planktonic cultures, but 16-fold higher concentrations were needed for more mature 7-day biofilms. In contrast, cefazolin, vancomycin, and rifampicin were substantially less active against both less and more mature biofilms than against planktonic cultures. Clinical relevance: Halicin is a promising antibiotic that may be effective against S. aureus osteomyelitis and infections on orthopaedic implants. Future studies should assess the translational value of halicin by testing its effects in animal models of orthopaedic infections; on the biofilms of other bacterial species, including multidrug-resistant bacteria; and in combination therapy with conventional antibiotics.Item Halicin remains active against Staphylococcus aureus in biofilms grown on orthopaedically relevant substrates(The British Editorial Society of Bone & Joint Surgery, 2024-03-04) Higashihira, Shota; Simpson, Stefanie J.; Morita, Akira; Suryavanshi, Joash R.; Arnold, Christopher J.; Natoli, Roman M.; Greenfield, Edward M.; Orthopaedic Surgery, School of MedicineAims: Biofilm infections are among the most challenging complications in orthopaedics, as bacteria within the biofilms are protected from the host immune system and many antibiotics. Halicin exhibits broad-spectrum activity against many planktonic bacteria, and previous studies have demonstrated that halicin is also effective against Staphylococcus aureus biofilms grown on polystyrene or polypropylene substrates. However, the effectiveness of many antibiotics can be substantially altered depending on which orthopaedically relevant substrates the biofilms grow. This study, therefore, evaluated the activity of halicin against less mature and more mature S. aureus biofilms grown on titanium alloy, cobalt-chrome, ultra-high molecular weight polyethylene (UHMWPE), devitalized muscle, or devitalized bone. Methods: S. aureus-Xen36 biofilms were grown on the various substrates for 24 hours or seven days. Biofilms were incubated with various concentrations of halicin or vancomycin and then allowed to recover without antibiotics. Minimal biofilm eradication concentrations (MBECs) were defined by CFU counting and resazurin reduction assays, and were compared with the planktonic minimal inhibitory concentrations (MICs). Results: Halicin continued to exert significantly (p < 0.01) more antibacterial activity against biofilms grown on all tested orthopaedically relevant substrates than vancomycin, an antibiotic known to be affected by biofilm maturity. For example, halicin MBECs against both less mature and more mature biofilms were ten-fold to 40-fold higher than its MIC. In contrast, vancomycin MBECs against the less mature biofilms were 50-fold to 200-fold higher than its MIC, and 100-fold to 400-fold higher against the more mature biofilms. Conclusion: Halicin is a promising antibiotic that should be tested in animal models of orthopaedic infection.Item Oral Vancomycin, Ursodeoxycholic Acid, or No Therapy for Pediatric Primary Sclerosing Cholangitis: A Matched Analysis(Wolters Kluwer, 2021) Deneau, Mark R.; Mack, Cara; Mogul, Douglas; Perito, Emily R.; Valentino, Pamela L.; Amir, Achiya Z.; DiGuglielmo, Matthew; Draijer, Laura G.; El-Matary, Wael; Furuya, Katryn N.; Gupta, Nitika; Hochberg, Jessica T.; Horslen, Simon; Jensen, M. Kyle; Jonas, Maureen M.; Kerkar, Nanda; Koot, Bart G. P.; Laborda, Trevor J.; Lee, Christine K.; Loomes, Kathleen M.; Martinez, Mercedes; Miethke, Alexander; Miloh, Tamir; Mohammad, Saeed; Ovchinsky, Nadia; Rao, Girish; Ricciuto, Amanda; Sathya, Pushpa; Schwarz, Kathleen B.; Shah, Uzma; Singh, Ruchi; Vitola, Bernadette; Zizzo, Andréanne; Guthery, Stephen L.; Pediatrics, School of MedicineBackground and aims: Many children with primary sclerosing cholangitis (PSC) receive oral vancomycin therapy (OVT) or ursodeoxycholic acid (UDCA). There is a paucity of data on whether these medications improve outcomes. Approach and results: We analyzed retrospective data from the Pediatric PSC Consortium. Children treated with OVT were matched 1:1:1 to those treated with UDCA or managed with observation (no treatment) based on the closest propensity score, ensuring similar baseline characteristics. Two hundred sixty-four patients (88 each with OVT, UDCA, or observation) had matching propensity scores and were similar in demographics, phenotype, immunosuppression, baseline biochemistry, and hepatic fibrosis. After 1 year in an intention-to-treat analysis, all outcome metrics were similar regardless of treatment group. In OVT, UDCA, and untreated groups, respectively: Gamma-glutamyltransferase normalized in 53%, 49%, and 52% (P = not significant [NS]), liver fibrosis stage was improved in 20%, 13%, and 18% and worsened in 11%, 29%, and 18% (P = NS), and the 5-year probability of liver transplant listing was 21%, 10%, and 12% (P = NS). Favorable outcome was associated with having a mild phenotype of PSC and minimal hepatic fibrosis. Conclusions: We presented the largest-ever description of outcomes on OVT in PSC and compared them to carefully matched patients on UDCA or no therapy. Neither OVT nor UDCA showed improvement in outcomes compared to a strategy of observation. Patients progressed to end-stage liver disease at similar rates. Spontaneous normalization of biochemistry is common in children receiving no therapy, particularly in the majority of children with a mild phenotype and an early stage of disease. Placebo-controlled treatment trials are needed to identify effective treatments for pediatric PSC.Item Treatment of infected dental pulps of monkeys with vancomycin and calcium hydroxide(1969) Gardner, Donald E.This study was undertaken to investigate histologically the effect of a combination of a potent antibiotic and calcium hydroxide when used as a medication in direct pulp therapy. The pulps of 74 teeth in one Macaca Speciosa monkey and two Macaca Nemestrina monkeys were exposed and left open to the oral environment for 48 hours to insure contamination. These pulps received direct treatment with one of four experimental medications: 1) starch and water; 2) vancomycin, starch and water; 3) calcium hydroxide, methyl cellulose and water; and 4) vancomycin, calcium hydroxide, methyl cellulose and water. In 30 days the teeth were removed from two animals and at 90 days from the other for histologic evaluation. A satisfactory response was observed in all the teeth treated with vancomycin, calcium hydroxide, methyl cellulose and water; in 94.4 per cent of the teeth treated with calcium hydroxide, methyl cellulose and water; in 33.3 per cent of those treated with vancomycin and starch; and in 11.2 per cent of those receiving starch and water. Complete bridging was seen in all teeth treated with vancomycin, calcium hydroxide, methyl cellulose and water. This was confirmed by the use of Procion brilliant red H-8BS dye and the study of serial sections. Under the conditions of this investigation, vancomycin in combination with calcium hydroxide and methyl cellulose was effective in controlling infection and promoting reparative dentin formation in monkeys.Item Treatment of infected dental pulps of monkeys with vancomycin and hyaluronidase(1968) Eggers, Eugene S. (Eugene Sherman), 1937-This study was undertaken to investigate histologically the effect of a combination of an antibiotic and an anti-inflammatory enzyme when used as a medication in direct pulp therapy. The pulps of 56 teeth in two Macaca Speciosa monkeys, exposed and left open to the oral environment for 24 hours to insure contamination, received direct treatment with one of four experimental medications: (1) vancomycin, starch, and hyaluronidase; (2) vancomycin, starch, and water; (3) starch and water; and (4) starch and hyaluronidase. At 30 days the teeth were removed from one animal and at 90 days•from the other for histologic interpretation. A satisfactory response was observed in 92.9 per cent of the teeth treated with vancomycin, starch, and hyaluronidase; in 71.5 per cent of the teeth treated with vancomycin, starch, and water; and in 42.9 per cent of the teeth treated with both starch and water and starch and hyaluronidase. None of the teeth treated with vancomycin, starch, and water and vancomycin, starch, and hyaluronidase became necrotic,while 35.7 per cent of the teeth treated with starch and water or starch and hyaluronidase became necrotic. Under the conditions of this investigation, vancomycin containing pulp capping agents are effective in controlling infection and in promoting reparative dentin formation in monkeys. The benefit of hyaluronidase when used in combination with vancomycin was questionable.Item Vancomycin-Induced Liver Injury, DRESS, and HLA-A*32:01(Elsevier, 2024-01-01) Asif, Bilal A.; Koh, Chistopher; Phillips, Elizabeth J.; Gu, Jiezhun; Li, Yi-Ju; Barnhart, Huiman; Chalasani, Naga; Fontana, Robert J.; Hayashi, Paul H.; Navarro, Victor J.; Hoofnagle, Jay H.; Medicine, School of MedicineBackground Intravenous vancomycin therapy can cause liver injury as well as “drug reaction with eosinophilia and systemic symptoms” (DRESS) syndrome. This study aimed to better define the clinical features and HLA associations of vancomycin-induced liver injury. Objective To describe clinical, biochemical, and temporal characteristics of vancomycin-induced liver injury. Methods Cases of liver injury with recent exposure to vancomycin who were enrolled in the US Drug-induced Liver Injury Network between 2004 and 2020 were assessed. Sequencing of HLA alleles was performed on stored blood samples. Results Among 1697 cases of drug-induced liver injury identified between 2004 and 2021, 9 (0.5%) were attributed to intravenous vancomycin. The 9 cases included 6 men, median age 60 years (range, 23-85 days), and treatment for 26 days (range, 1-34 days). The clinical presentation was DRESS syndrome in 8 patients, of whom 6 received corticosteroids. Liver injury varied from hepatocellular to cholestatic and from mild (n = 5) to fatal (n = 1). In survivors, liver injury and DRESS syndrome ultimately resolved. HLA typing demonstrated the HLA-A∗32:01 allele in 7 vancomycin cases (78%, all with DRESS syndrome), versus 1 of 81 cases (1.2%) exposed but not attributed to vancomycin, and 113 of 1708 cases (6.6%) without vancomycin exposure. The allele frequency in vancomycin cases was 0.44 compared with less than 0.04 in US populations. Conclusions Vancomycin-induced liver injury is commonly associated with DRESS syndrome and linked to HLA-A∗32:01. HLA-A∗32:01 testing could be considered early to risk-stratify patients using long-term intravenous vancomycin therapy.