UHPLC-MS/MS method for simultaneous quantification of doripenem, meropenem, ciprofloxacin, levofloxacin, pazufloxacin, linezolid, and tedizolid in filtrate during continuous renal replacement therapy.

BACKGROUND: Since severe infections frequently cause acute kidney injury (AKI), continuous renal replacement therapy (CRRT) is often initiated for regulation of inflammatory mediators and renal support. Thus, it is necessary to decide the antibiotic dosage considering the CRRT clearance in addition to residual renal function. Some of the hemofilters used in CRRT are known to adsorb antibiotics, and clearance of antibiotics may differ depending on the adsorptive characteristics of hemofilters. Although assay systems for blood and CRRT filtrate concentrations are required, no method for measuring antibiotics concentrations in filtrate has been reported. We developed a UHPLC-MS/MS method for simultaneous quantification of antibiotics commonly used in ICU, comprising carbapenems [doripenem (DRPM) and meropenem (MEPM)], quinolones [ciprofloxacin (CPFX), levofloxacin (LVFX) and pazufloxacin (PZFX)] and anti-MRSA agents [linezolid (LZD), and tedizolid (TZD)] in CRRT filtrate samples. METHODS: Filtrate samples were pretreated by protein precipitation. The analytes were separated with an ACQUITY UHPLC CSH C18 column under a gradient mobile phase consisting of water and acetonitrile containing 0.1% formic acid and 2 mM ammonium formate. RESULTS: The method showed good linearity over wide ranges. Within-batch and batch-to-batch accuracy and precision for each drug fulfilled the criteria of the US Food and Drug Administration guidance. The recovery rate was more than 87.20%. Matrix effect ranged from 99.57% to 115.60%. Recovery rate and matrix effect did not differ remarkably between quality control samples at different concentrations. CONCLUSION: This is the first report of a simultaneous quantification method of multiple antibiotics in filtrate of CRRT circuit.

A case of improvement of clozapine-induced low leukocyte counts by adenine, cepharanthin and ninjin-yoei-to in a patient with treatment-resistant schizophrenia.

BACKGROUND: Although clozapine is the optimal drug for patients with treatment-resistant schizophrenia, the drug has harmful adverse effects such as leukopenia. Adenine and cepharanthine are known to be effective for radiation- or drug-induced leukopenia. Furthermore, ninjin-yoei-to, a Chinese herbal medicine, augments the production of granulocyte-macrophage colony-stimulating factor. Thus, these drugs may be useful for clozapine-induced leukopenia. CASE PRESENTATION: A 21 years-old woman with schizophrenia was hospitalized for initiation of clozapine treatment. Despite concomitant use of adenine, cepharanthine, and lithium carbonate having activities of increasing leukocytes, a decrease in leukocyte counts occurred after the initiation of clozapine. Additional administration of ninjin-yoei-to increased leukocyte counts, which prevented the development of leukopenia. CONCLUSIONS: This is the first case that concomitant use of adenine, cepharanthin, and ninjin-yoei-to exhibited the effectiveness of reversing the decrease in leukocytes caused by clozapine. Monitoring leukocyte counts and preventing leukopenia are essential for successful treatment with clozapine for refractory schizophrenia. These medicines may be a potential option for preventing clozapine-induced leukopenia.

Pharmacokinetics of ceftriaxone in patients undergoing continuous renal replacement therapy.

BACKGROUND: The duration of time for which the serum levels exceed the minimum inhibitory concentration (MIC) is an important pharmacokinetics (PK)/pharmacodynamics (PD) parameter correlating with efficacy for the antibiotic, ceftriaxone (CTRX). However, no reports exist regarding the PK or PD in patients undergoing continuous renal replacement therapy (CRRT). The purpose of this study was to examine the PK and safety of CTRX in patients undergoing CRRT in order to establish safer and more effective regimens. METHODS: CTRX (1 g once a day) was intravenously administered four or more times to nine patients undergoing CRRT. Blood was collected after administration to measure CTRX concentrations in serum and the filtration fraction of CRRT by high-performance liquid chromatography. In addition to calculating PK parameters from serum CTRX, we (a) estimated by simulation CTRX concentrations when the dose interval was extended to once every 2 or 3 days, (b) calculated CTRX clearance via CRRT from CTRX concentrations in the filtration fraction, and (c) assessed the safety of CTRX use. RESULTS: Total body clearance and the half-life of CTRX were 7.46 mL/min (mean) and 26.5 h, respectively, in patients undergoing CRRT. CTRX was found in the filtration fraction, and the estimated clearance by CRRT was about 70% of total body clearance. Simulations revealed that even when the dose interval is increased to 2 or 3 days, CTRX would retain its efficacy. CONCLUSIONS: Our findings suggest that, depending on the condition of patients undergoing CRRT, CTRX could be used safely against pathogens with a CTRX MIC ≤2 µg/mL, even when extending the dose interval.

Is peak concentration needed in therapeutic drug monitoring of vancomycin? A pharmacokinetic-pharmacodynamic analysis in patients with methicillin-resistant staphylococcus aureus pneumonia.

BACKGROUND: We analyzed the pharmacokinetic-pharmacodynamic relationship of vancomycin to determine the drug exposure parameters that correlate with the efficacy and nephrotoxicity of vancomycin in patients with methicillin-resistant Staphylococcus aureus pneumonia and evaluated the need to use peak concentration in therapeutic drug monitoring (TDM). METHODS: Serum drug concentrations of 31 hospitalized patients treated with vancomycin for methicillin-resistant S. aureus pneumonia were collected. RESULTS: Significant differences in trough concentration (Cmin)/minimum inhibitory concentration (MIC) and area under the serum concentration-time curve (AUC0-24)/MIC were observed between the response and non-response groups. Significant differences in Cmin and AUC0-24 were observed between the nephrotoxicity and non-nephrotoxicity groups. Receiver operating characteristic curves revealed high predictive values of Cmin/MIC and AUC0-24/MIC for efficacy and of Cmin and AUC0-24 for safety of vancomycin. CONCLUSIONS: These results suggest little need to use peak concentration in vancomycin TDM because Cmin/MIC and Cmin are sufficient to predict the efficacy and safety of vancomycin.

Establishment and clinical application of a highly sensitive enzyme immunoassay for determination of N-acetyl-seryl-aspartyl-lysyl-proline.

N-acetyl-seryl-aspartyl-lysyl-proline (AcSDKP) is a natural inhibitor of pluripotent hematopoietic stem cell proliferation and is normally found in human plasma. Because AcSDKP is hydrolyzed by the N-terminal active site of angiotensin converting enzyme and partially eliminated in urine, its plasma level is a result of a complex balance between its production, hydrolysis by ACE, and renal elimination. In this study, we attempted to establish an enzyme immunoassay (EIA) for quantifying AcSDKP-like immunoreactive substance (IS), which is applicable for monitoring plasma AcSDKP levels in healthy subjects and patients with chronic renal failure. Using ß-D-galactosidase-labeled Gly-γAbu-SDKP as a marker antigen, an anti-rabbit IgG-coated immunoplate as a bound/free separator and 4-methylumbelliferyl-ß-D-galactopyranoside as a fluorogenic substrate, a highly sensitive and specific EIA was developed for the quantification of AcSDKP-IS in human plasma. The lower limit of quantification was 0.32 fmol/well, and the sharp inhibition competitive EIA calibration curve obtained was linear between 8.0 and 513 fmol/ml. This EIA was so sensitive that only 10 µl plasma sample was required for a single assay. The coefficients of variation (reproducibility) for human plasma concentrations of 0.2 and 2.1 pmol/ml were 7.2 and 7.7%, respectively, for inter-assay and 13.3 and 7.8% for intra-assay comparisons. Plasma AcSDKP-IS level was significantly higher in patients with chronic renal failure (0.92 ± 0.39 pmol/ml) compared with healthy subjects (0.29 ± 0.07 pmol/ml). These results suggest that our EIA may be useful to evaluate plasma AcSDKP level as a biomarker in various patients.

Comparison of the effects of pantethine and fursultiamine on plasma gastrointestinal peptide levels in healthy volunteers.

Pantethine and fursultiamine have been evaluated for their clinical usefulness in the treatment and prevention of uncomplicated postoperative adhesive intestinal obstruction. In recent years, the actions of drugs used to treat gastrointestinal diseases have been elucidated pharmacologically from the viewpoints of gastrointestinal peptide levels. We examined the effects of pantethine and fursultiamine on plasma levels of calcitonin gene-related peptide (CGRP)-, vasoactive intestinal polypeptide (VIP)-, motilin- and substance P (SP)-like immunoreactive substances (IS) in healthy subjects. An open-labeled study was conducted on five healthy volunteers. Each subject was administered a single oral dose of pantethine, fursultiamine and placebo at intervals of one month. Venous blood samples were collected before and at 20, 40, 60, 90, 120, 180 and 240 min after each administration. Plasma peptide levels were measured using a highly sensitive enzyme immunoassay. A single oral dose of pantethine resulted in significant increases of plasma CGRP- and VIP-IS levels compared to placebo. Furthermore, areas under the plasma concentration-time curves (AUC(0-240)) of CGRP- and VIP-IS were significantly higher after pantethine administration compared with placebo. On the other hand, fursultiamine had no effect on plasma levels and AUC(0-240) of CGRP-, VIP-, motilin- and SP-IS. This study demonstrated the different effects of pantethine and fursultiamine from the viewpoint of plasma gastrointestinal peptide changes. The pharmacological effects of pantethine may be closely related to the changes in plasma CGRP- and VIP-IS levels.

Effects of pirenzepine on Dai-kenchu-to-induced elevation of the plasma neuropeptide levels in humans.

Dai-kenchu-to has been used for the treatment of abdominal obstructions, including bowel obstructions and a feeling of coldness in the abdomen. We reported that Dai-kenchu-to increases plasma neuropeptide [motilin, vasoactive intestinal polypeptide (VIP), serotonin, calcitonin gene-related peptide (CGRP), and substance P]-like immunoreactive substances (IS) levels and that its pharmacologic effects on the gastrointestine are due to changes in gastrointestinal mucosa-regulatory peptide levels. We examined the effects of the selective M(1) muscarinic receptor antagonist pirenzepine on the elevation of Dai-kenchu-to-induced plasma neuropeptide (gastrin, motilin, somatostatin, VIP, CGRP, substance P)-IS levels in human volunteers and the area under the plasma neuropeptide concentration-time curve from 0 to 240 min (AUC(0-->240 min)), which were calculated from the plasma neuropeptide concentration-time curves from each volunteers. Oral pretreatment with pirenzepine reduced the Dai-kenchu-to-induced elevation of plasma motilin and VIP-IS levels and AUC(0-->240 min). Combined treatment with Dai-kenchu-to and pirenzepine increased plasma somatostatin-IS levels and decreased plasma gastrin-IS levels and had no effects on plasma CGRP- and substance P-IS levels and AUC(0-->240 min) compared with administration of Dai-kenchu-to alone. Dai-kenchu-to appeared to induce the release of motilin and VIP into plasma mainly through the activation of M(1) muscarinic receptors, and pirenzepine may affect the pharmacologic action of Dai-kenchu-to by elevation of plasma motilin and VIP levels.

Effects of some kampo medicines on plasma levels of neuropeptide Y under venipuncture stress.

Some traditional Chinese herbal (Kampo) medicines have recently been evaluated for their clinical usefulness in stress and depression. These medicines have modulatory effects on the hypothalamic-pituitary-adrenal axis and sympathetic nervous system (SNS). We examined the effects of Rikkunshi-to, Hange-shashin-to, Hange-koboku-to, and Ninjin-to on plasma levels of neuropeptide Y (NPY), which is the representative neurotransmitter of the SNS, under venipuncture stress. Rikkunshi-to and Hange-shashin-to suppressed increases in plasma NPY-immunoreactive substance levels compared with the response to a placebo. In this study, Rikkunshi-to and Hange-shashin-to altered plasma levels of NPY under venipuncture stress. These effects might be beneficial in stress-related diseases and our results suggest that these medicines have clinical pharmacologic activity.

Effects of Ninjin-to on levels of calcitonin gene-related peptide and substance P in human plasma.

The herbal medicine Ninjin-to has been used for the treatment of gastroenteritis, esogastritis, gastric atony, gastrectasis, vomiting, and anorexia. One of the mechanisms of the empirical effects is assumed to be due to local changes in neuropeptide levels. Sensory afferent neurons in the gastrointestinal mucosa regulate neuropeptides [calcitonin gene-related peptide (CGRP), substance P, etc.], which play various physiologic roles. To determine whether the pharmacologic effects of Ninjin-to on the gastrointestine are due to changes in gastrointestinal mucosa regulatory peptide levels, we examined the effects of Ninjin-to on the levels of CGRP-like immunoreactive substances (IS) and substance P-IS in plasma taken from five healthy subjects. A single oral administration of 6.0 g of Ninjin-to caused significant increases in plasma CGRP-IS at 40 min and 60 min, and in substance P-IS levels at 90 min, compared with a placebo group. These results may indicate that the pharmacologic actions of Ninjin-to are closely related to changes in CGRP-IS and substance P-IS levels.

Dai-kenchu-to raises levels of calcitonin gene-related peptide and substance P in human plasma.

Sensory afferent neurons in the gastrointestinal mucosa regulate neuropeptides [calcitonin gene-related peptide (CGRP), substance P, etc.], which play various physiologic roles and are gastroprotective. To determine whether the pharmacologic effects of Dai-kenchu-to (DKCT) on the gastrointestine are due to changes in gastrointestinal mucosa regulatory peptide levels, we examined the effects of the DKCT on the levels of CGRP-like immunoreactive substances (IS) and substance P-IS in plasma taken from five healthy subjects. A single oral administration of DKCT 7.5 g caused significant increases in plasma CGRP-IS at 40 min, and in substance P-IS levels at 20 and 60 min, compared with a placebo group. The present study may indicate that the pharmacologic action of DKCT is closely related to changes in CGRP- and substance P-IS levels.

Effect of Sho-hange-ka-bukuryo-to on gastrointestinal peptide concentrations in the plasma of healthy human subjects.

Sho-hange-ka-bukuryou-to, a traditional Chinese herbal (Kampo) medicine, has been used to treat hyperemesis of pregnancy, nausea and vomiting. Most traditional herbal medicines are prepared from several herbs. For example, Sho-hange-ka-bukuryo-to is prepared from three herbs: Pinelliae Tuber, Zingiberis Rhizoma and Hoelen. Thus, to determine the precise mechanism of the pharmacological effects of Chinese herbal medicines is too difficult. So we have elucidated the effect of some Chinese herbal medicines by examining the change of the plasma levels of brain-gut peptides. In this study, we investigated the effects of Sho-hange-ka-bukuryo-to on the plasma levels of gut-regulated peptides (gastrin, somatostatin, motilin and vasoactive intestinal peptide (VIP)) and gastrointestinal mucosa regulatory neuropeptides (calcitonin gene-related peptide (CGRP) and substance P) in healthy human subjects. A single oral administration of Sho-hange-ka-bukuryo-to caused significant increases in plasma somatostatin-, CGRP- and substance P-immunoreactive substance (IS) levels, compared with a placebo group. Transient elevation of gastrin-IS levels in the placebo group was inhibited by the administration of Sho-hange-ka-bukuryo-to, but the medicine showed no effects on plasma motilin- or VIP-IS levels. In conclusion, these results might indicate that the pharmacological action of Sho-hange-ka-bukuryo-to is closely related to changes in gastrin-, somatostatin-, CGRP- and substance P-IS levels in human plasma.

Comparison of the effects of Sho-hange-ka-bukuryo-to and Nichin-to on human plasma adrenocorticotropic hormone and cortisol levels with continual stress exposure.

Sho-hange-ka-bukuryo-to and Nichin-to, traditional Chinese herbal (Kampo) medicines have been used to treat vomiting and nausea. Traditional herbal medicines have frequently been used in the empirical treatment. Some patients who take these medicines have no organic disease but have conditions classified as non-ulcer dyspepsia (NUD). To determine the pharmacological effects of Sho-hange-ka-bukuryo-to, Nichin-to, and the two herbs (Pinelliae Tuber and Zingiberis Rhizoma, both of which are included in Sho-hange-ka-bukuryo-to and Nichin-to), we examined the effects of these medicines on the plasma levels of adrencorticotropic hormone (ACTH) and cortisol under stress conditions by repetitive blood sampling. After a single administration of Kampo medicine or a placebo, venous blood samples were taken before and 20-240 min after administration. A single administration of Sho-hange-ka-bukuryo-to caused significant suppression of an increase in plasma ACTH-immunoreactive substance (IS) levels at 120 to 180 min and tended to suppress increases in plasma cortisol levels at 240 min, compared with the response to a placebo. A single administration of Nichin-to caused significant suppression of increases in plasma ACTH-IS levels at 120 min compared with a placebo group, but had no effect on plasma cortisol levels. Pinelliae Tuber had no significant effects in plasma ACTH-IS or cortisol, but Zingiberis Rhizoma significantly suppressed the increase of ACTH-IS (120 min) and cortisol (180 min). These medicines have a modulatory effect on the hypothalamo-pituitary-adrenal (HPA) axis and autonomic nervous function. These effects might be beneficial in stress-related disease and suggest that this medicine has clinical pharmacological activity.

Effects of Hange-koboku-to (Banxia-houpo-tang) on neuropeptide levels in human plasma and saliva.

Hange-koboku-to (Banxia-houpo-tang), a Chinese herbal (Kampo) medicine, has been used for improvement of hoarse voice, something foreign body sensation in the throat and/or esophagus, and swallowing reflex, among other conditions. One of the mechanisms of the empirical effects is assumed to be due to local changes in neuropeptide levels locally. We investigated the effects of Hange-koboku-to on neuropeptides, calcitonin gene-related peptide (CGRP), substance P, somatostatin, and vasoactive intestinal peptide (VIP) in plasma and saliva, as well as on salivary secretion in healthy subjects. A single oral administration of Hange-koboku-to caused significant increases in substance P-immunoreactive substance (IS) (40 min) in plasma, and slightly increased in CGRP-IS and somatostatin-IS in plasma compared with placebo. In saliva neuropeptides, Hange-koboku-to caused significant increases in substance P-IS (20 min) and somatostatin-IS (40, 60 min), and a slight increase in VIP-IS. However, a single Hange-koboku-to stimulation did not have a significant effect of sialosis volume. These results seem to suggest that Hange-koboku-to improves hoarse voice, something foreign body sensation in the throat and esophagus, and swallowing reflex disorder, by stimulation of neuropeptidergic nerves locally.

Comparison of the effects of hange-shashin-to and rikkunshi-to on human plasma calcitonin gene-related peptide and substance P levels.

Regarding the gastroprotective function as a neural emergency system, sensory afferent neurons in the gastrointestinal mucosa regulate neuropeptide (calcitonin gene-related peptide (CGRP), substance P, etc.) levels, and those peptides play various physiological roles. To determine whether the pharmacological effects of Hange-shashin-to and Rikkunshi-to on the gastrointestine are due to changes in gastrointestinal mucosa regulatory peptides levels, we investigated the levels of CGRP-like immunoreactive substances (IS) and substance P-IS in plasma from healthy subjects. A single oral administration of Hange-shashin-to caused significant increases in CGRP-IS (40-60 min) and substance P-IS (60-180 min) levels in the plasma compared with the levels induced by a placebo. Rikkunshi-to and a 5.0 g Pinelliae tuber extract had no significant effect on CGRP-IS and substance P-IS levels. Extract of a 2.5 g Zingiberis rhizoma significantly caused increases in CGRP-IS at 40 min and in substance P-IS at 60 min. These results, in comparison with Kampo medicines, might indicate that the pharmacological actions of Hange-shashin-to closely are related to changes in CGRP-IS and substance P-IS levels, while Zingiberis rhizoma partially might participate in those effects of Hange-shashin-to.

Some gastrointestinal function regulatory Kampo medicines have modulatory effects on human plasma adrenocorticotropic hormone and cortisol levels with continual stress exposure.

Rikkunshi-to, a gastrointestinal function regulatory traditional Chinese herbal (Kampo) medicine, has recently been evaluated for its clinical usefulness in stress and depression. This medicine has modulatory effects on the hypothalamo-pituitary-adrenal axis and autonomic nervous function. We examined the effect of Rikkunshi-to and the other gastrointestinal function regulatory Kampo medicines, Hange-shashin-to, Hange-koboku-to, and Ninjin-to, on the plasma levels of adrenocorticotropic hormone (ACTH) and cortisol under stress conditions by repetitive blood sampling. Rikkunshi-to, Hange-shashin-to, and Hange-koboku-to significantly suppressed increases in plasma ACTH-immunoreactive substance (IS) levels compared with the response to a placebo. Rikkunshi-to and Hange-shashin-to significantly suppressed increases in plasma cortisol levels compared with the response to placebo. Ninjin-to had no significant effect on plasma ACTH-IS and cortisol levels. In this study, Rikkunshi-to, Hange-shashin-to, and Hange-koboku-to (partially) regulated plasma ACTH and cortisol levels under stress. These modulatory effects might be beneficial in stress-related disease and suggest that these medicines have clinical pharmacologic activity.

Hange-shashin-to raises levels of somatostatin, motilin, and gastrin in the plasma of healthy subjects.

Hange-shashin-to has been used for chronic hypofunction of the gastrointestinal tract and to improve functional abnormalities of the upper and lower gastrointestinal system. To determine whether the pharmacological effects of Hange-shashin-to are due to gut-regulatory peptide levels, we developed a sensitive and specific double-antibody enzyme immunoassay (EIA) for detecting motilin and also examined the levels of somatostatin-, motilin-, gastrin-, and vasoactive intestinal peptide (VIP)-immunoreactive substances (IS) in plasma from healthy subjects. We developed a sensitive (3.5 pg, 1.4 pg/well) and specific (carboxy-terminal region) EIA for motilin. A single oral administration of Hange-shashin-to 6.0 g caused significant increases somatostatin-IS (20-60 min), motilin-IS (40 min), and gastrin-IS (40-90 min) levels in plasma compared with levels in a placebo group. Hange-shashin-to had no significant effect on VIP-IS levels after single administration. These changes in hormone levels (somatostatin, motilin, and gastrin) might relate to normalization of the upper and lower gastrointestinal system by Hange-shashin-to.