BACKGROUND Plasma teicoplanin concentrations do not reach the therapeutic range in several patien... more BACKGROUND Plasma teicoplanin concentrations do not reach the therapeutic range in several patients with hematological malignancies. Nevertheless, the characteristics of the population pharmacokinetic (PPK) models have not been clarified for malignancy. The decrease in the teicoplanin concentration in patients with cancer has been attributed to augmented renal clearance (ARC). It is essential to identify the causative factors of ARC to construct a PPK model to optimize the administration method. The authors aimed to establish a PPK model and develop an appropriate dosing regimen for teicoplanin in patients with hematological malignancies. METHODS PPK analysis was performed using therapeutic drug monitoring (TDM) data from 119 patients with hematological malignancies. The developed model was verified by predictive performance. RESULTS The covariates affecting systemic clearance were serum creatinine, presence or absence of neutropenia (<500/μL), and body size descriptor. Patients with hematologic malignancies and neutropenia showed a 25% increase in clearance compared with those with a normal neutrophil count. The PPK model was constructed based on the presence or absence of neutropenia. This model allowed the selection of the most appropriate dosage regimen out of those recommended by the TDM guidelines for patients with eGFR of >60 mL/min/1.73 m2. The PPK model predicted a dosing regimen for achieving a 10% improvement in the coverage probability of the target concentration range during the loading and maintenance phases. CONCLUSIONS The PPK model may help optimize dose regimens and evaluate dosing methods, using comparative simulations, in patients with hematological malignancies.
When supercoiled plasmid DNA was incubated with 2,2&#39;-azobis (2-amidinopropane)hydrochlori... more When supercoiled plasmid DNA was incubated with 2,2&#39;-azobis (2-amidinopropane)hydrochloride (AAPH) at pH 7.4 in the presence and absence of oxygen, the DNA single strands were effectively cleaved. The breaking in the presence of oxygen was not inhibited by superoxide dismutase and catalase, but inhibited by mannitol, ethanol, butyl hydroxyanisole, thiol compounds, tertiary amines and spin trapping agents N-tert-butyl-alpha-phenylnitrone (PBN) and 5,5-dimethyl-1-pyrroline N-oxide (DMPO). The breaking in the absence of oxygen was inhibited by ethanol, a tertiary amine and PBN. By electron spin resonance spin-trapping with PBN, the carbon-centered radical was detected both in the presence and the absence of oxygen. Hydroxyl radical was detected by use of DMPO only in the presence of oxygen. The DNA breaking activity of AAPH was found to be due primarily to the aliphatic carbon-centered radical. While the reactivity of carbon-centered radicals have received little attention, the aliphatic carbon-centered radical generated from AAPH was found to be highly reactive to break the DNA strands.
When supercoiled plasmid DNA was incubated with 2,2&#39;-azobis (2-amidinopropane)hydrochlori... more When supercoiled plasmid DNA was incubated with 2,2&#39;-azobis (2-amidinopropane)hydrochloride (AAPH) at pH 7.4 in the presence and absence of oxygen, the DNA single strands were effectively cleaved. The breaking in the presence of oxygen was not inhibited by superoxide dismutase and catalase, but inhibited by mannitol, ethanol, butyl hydroxyanisole, thiol compounds, tertiary amines and spin trapping agents N-tert-butyl-alpha-phenylnitrone (PBN) and 5,5-dimethyl-1-pyrroline N-oxide (DMPO). The breaking in the absence of oxygen was inhibited by ethanol, a tertiary amine and PBN. By electron spin resonance spin-trapping with PBN, the carbon-centered radical was detected both in the presence and the absence of oxygen. Hydroxyl radical was detected by use of DMPO only in the presence of oxygen. The DNA breaking activity of AAPH was found to be due primarily to the aliphatic carbon-centered radical. While the reactivity of carbon-centered radicals have received little attention, the aliphatic carbon-centered radical generated from AAPH was found to be highly reactive to break the DNA strands.
BACKGROUND Plasma teicoplanin concentrations do not reach the therapeutic range in several patien... more BACKGROUND Plasma teicoplanin concentrations do not reach the therapeutic range in several patients with hematological malignancies. Nevertheless, the characteristics of the population pharmacokinetic (PPK) models have not been clarified for malignancy. The decrease in the teicoplanin concentration in patients with cancer has been attributed to augmented renal clearance (ARC). It is essential to identify the causative factors of ARC to construct a PPK model to optimize the administration method. The authors aimed to establish a PPK model and develop an appropriate dosing regimen for teicoplanin in patients with hematological malignancies. METHODS PPK analysis was performed using therapeutic drug monitoring (TDM) data from 119 patients with hematological malignancies. The developed model was verified by predictive performance. RESULTS The covariates affecting systemic clearance were serum creatinine, presence or absence of neutropenia (<500/μL), and body size descriptor. Patients with hematologic malignancies and neutropenia showed a 25% increase in clearance compared with those with a normal neutrophil count. The PPK model was constructed based on the presence or absence of neutropenia. This model allowed the selection of the most appropriate dosage regimen out of those recommended by the TDM guidelines for patients with eGFR of >60 mL/min/1.73 m2. The PPK model predicted a dosing regimen for achieving a 10% improvement in the coverage probability of the target concentration range during the loading and maintenance phases. CONCLUSIONS The PPK model may help optimize dose regimens and evaluate dosing methods, using comparative simulations, in patients with hematological malignancies.
When supercoiled plasmid DNA was incubated with 2,2&#39;-azobis (2-amidinopropane)hydrochlori... more When supercoiled plasmid DNA was incubated with 2,2&#39;-azobis (2-amidinopropane)hydrochloride (AAPH) at pH 7.4 in the presence and absence of oxygen, the DNA single strands were effectively cleaved. The breaking in the presence of oxygen was not inhibited by superoxide dismutase and catalase, but inhibited by mannitol, ethanol, butyl hydroxyanisole, thiol compounds, tertiary amines and spin trapping agents N-tert-butyl-alpha-phenylnitrone (PBN) and 5,5-dimethyl-1-pyrroline N-oxide (DMPO). The breaking in the absence of oxygen was inhibited by ethanol, a tertiary amine and PBN. By electron spin resonance spin-trapping with PBN, the carbon-centered radical was detected both in the presence and the absence of oxygen. Hydroxyl radical was detected by use of DMPO only in the presence of oxygen. The DNA breaking activity of AAPH was found to be due primarily to the aliphatic carbon-centered radical. While the reactivity of carbon-centered radicals have received little attention, the aliphatic carbon-centered radical generated from AAPH was found to be highly reactive to break the DNA strands.
When supercoiled plasmid DNA was incubated with 2,2&#39;-azobis (2-amidinopropane)hydrochlori... more When supercoiled plasmid DNA was incubated with 2,2&#39;-azobis (2-amidinopropane)hydrochloride (AAPH) at pH 7.4 in the presence and absence of oxygen, the DNA single strands were effectively cleaved. The breaking in the presence of oxygen was not inhibited by superoxide dismutase and catalase, but inhibited by mannitol, ethanol, butyl hydroxyanisole, thiol compounds, tertiary amines and spin trapping agents N-tert-butyl-alpha-phenylnitrone (PBN) and 5,5-dimethyl-1-pyrroline N-oxide (DMPO). The breaking in the absence of oxygen was inhibited by ethanol, a tertiary amine and PBN. By electron spin resonance spin-trapping with PBN, the carbon-centered radical was detected both in the presence and the absence of oxygen. Hydroxyl radical was detected by use of DMPO only in the presence of oxygen. The DNA breaking activity of AAPH was found to be due primarily to the aliphatic carbon-centered radical. While the reactivity of carbon-centered radicals have received little attention, the aliphatic carbon-centered radical generated from AAPH was found to be highly reactive to break the DNA strands.
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