Decreased plasma acetaminophen glucuronide/acetaminophen concentration ratio warns the onset of acetaminophen-induced liver injury.

Acetaminophen (APAP)-induced liver injury (AILI) is the most common cause of acute liver failure. Although the mechanisms that trigger AILI are well known, it is less understood how to halt AILI progression and facilitate liver recovery. Therefore, it is necessary to understand the pathophysiology of APAP hepatotoxicity in patients and to examine predictive/preventive markers. In a clinical study, we had a case in which aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels increased in a patient with a low ratio of APAP glucuronide concentration (AP-G)/APAP plasma concentration. Then a reverse translational study was conducted for clarifying this clinical question. The relationship between plasma AP-G/APAP concentration ratio and the levels of AST and ALT was examined by in vivo and in vitro experiments. In in vivo experiments, 10-week-old rats showed lower UGT activity, lower AP-G/APAP concentration ratios, and higher AST and ALT levels than 5-week-old rats. This suggests an inverse correlation between the AP-G/APAP concentration ratio and the AST, ALT levels in APAP-treated rats. Furthermore, as a result of the in vitro experiment, it was confirmed that the cell viability decreased when the AP-G/APAP concentration ratio in the culture medium decreased. Since the decrease in the plasma AP-G/APAP concentration ratio appears earlier than the increase of AST and ALT levels, the ratio might be a presymptomatic marker of AILI. When APAP is used for a long time, it is recommended to perform therapeutic drug monitoring of the AP-G/APAP concentration ratio, which is a predictive/preventive marker of AILI.

Role of caspase-8 and/or -9 as biomarkers that can distinguish the potential to cause toxic- and immune related-adverse event, for the progress of acetaminophen-induced liver injury.

AIMS: Acetaminophen (APAP) overdose can cause acute liver failure. Although it is well known that APAP-induced liver injury (AILI) is caused by toxic mechanism, recently it is also reported to be immune related. However, the detail of the mechanism has been unclear. Therefore, elucidation of the pathophysiology is required. MAIN METHODS: In AILI model rats (800 mg/kg), the levels of AST, ALT and Caspase (C)-3/-8/-9 levels were measured. In in vitro study using human hepatocyte cells (FLC-4) and THP-1 cells, APAP (0.03-1.0 mM) were added to FLC-4 and the cell viability, C-9, cytochrome c, mitochondria membrane potential, and glutathione levels of FLC-4 and inflammasome activation of THP-1 were evaluated. KEY FINDINGS: In AILI model rats, the levels of AST and ALT were increased only at 12-24 h. C-3/-9 levels rose at 6-9 h, whereas C-8 level rose hours later, moreover, 24 h after; C-3/-8/-9 levels re-rose. In FLC-4 cells, cytochrome c was released from the mitochondria which is promoted by oxidative stress due to drug metabolism and C-9 was activated. Thus, AILI was caused mitochondrial damage by NAPQI as early reaction (first stage). In the next stage, inflammasomes of human antigen presenting cells, which released inflammatory cytokines were activated by damage-associated molecular patterns (DAMPs) released from damaged hepatocyte by APAP. SIGNIFICANCE: It is confirmed that AILI includes immune related mechanism. Thereby, in case of N-acetylcysteine refractory, additional administration of steroid hormones should be effective and recommended as a novel strategy for AILI with immune related adverse event (irAE).

The Efficacy of the Transdermal Isosorbide Dinitrate Patch in Patients With Chronic Limb-Threatening Ischemia.

Recently, the number of patients with peripheral artery disease (PAD), including those with chronic limb-threatening ischemia (CLTI), has increased because of the increasing number of diabetic or dialysis patients worldwide. Revascularization is an important therapy for patients with CLTI. However, we sometimes experience refractory cases with insufficient peripheral circulation or microcirculation after revascularization. In this situation, additional therapy can be administered, such as low-density lipoprotein apheresis, high-pressure oxygen therapy, and spinal cord stimulation. However, they are not effective in some cases. Some reports have also indicated that transdermal isosorbide dinitrate patch (ISDN-P) is a useful therapy for PAD. As the efficacy of ISDN-P for patients with CLTI is not well-known, we examined it in this study. We assessed the skin perfusion pressure (SPP) after affixing an ISDN-P on the foot, because SPP measurement has proved useful in the assessment of PAD and is a good indicator of wound healing potential. The SPP (dorsal and plantar aspects) after ISDN-P application on the foot of healthy volunteers increased (n = 8; mean ± SD, 12.6 ± 7.9 [P = .12], and 21.2 ± 7.7 mm Hg [P < .05], respectively), as did SPP of patients with CLTI (n = 10; mean ± SD, 19.8 ± 2.5 [P < .01], and 14.1 ± 5.9 mm Hg [P < .05], respectively). All the patients who received an ISDN-P on the foot had no major complication, and no significant change in blood pressure. In conclusion, the ISDN-P is one of the effective and safe therapies for patients with CLTI.

Giant Hepatic Cyst: A Possible Cause of Inferior Vena Cava Syndrome.

An 80-year-old man was transferred to our institution with lower limb edema and worsening dyspnea following the administration of diuretic medication. Transthoracic echocardiography and computed tomography revealed a giant hepatic cyst (176×190 mm) compressing his right atrium and inferior vena cava (IVC). Laparoscopic cyst deroofing combined with omental packing and subsequent tube drainage immediately alleviated all his symptoms. The procedure was uneventful, and he was discharged without any complications on postoperative day 9; he had no recurrent symptoms or hepatic cysts at the postoperative 2-month follow-up. Therefore, a giant hepatic cyst can cause IVC syndrome, and laparoscopic deroofing is a beneficial approach for the treatment of accessible cysts.

Milestone Studies on Ion-exclusion Chromatography of Ionic and Nonionic Substances Utilizing Multifunctional Separation Mechanism of Ion-exchange Resins.

Ion-exclusion chromatography (IEC) is categorized as a type of ion chromatography and is recognized as a simple and convenient water quality monitoring technology for a variety of ionic and nonionic substances. This review, mainly focusing on historical milestone studies by various authors, outlines the archives that concern the separation sciences and practical applications obtained from a variety of IEC modes used for water-quality monitoring as follows: (1) early-developed IEC; (2) IEC using enhanced conductivity detection for weak ionic substance; (3) IEC using nonionic substances eluents such as sugars or polyols; (4) vacancy IEC based on a novel separation concept; (5) applications to the water quality monitoring of inorganic ionic-nutrients; (6) simultaneous IEC and cation-exchange chromatography of anions and cations; and (7) the multicomponent IEC combining different separation modes and detection methods with the expansion of applicable fields, such as for food analysis or material evaluations.

Effect of postprandial moderate-intensity walking for 15-min on glucose homeostasis in type 2 diabetes mellitus patients.

AIM: Diabetes patients usually have a low activity level and complain about lack of time. Therefore, we investigated the effect of short time, postprandial moderate-intensity exercise on glucose homeostasis in type 2 diabetes patients. METHODS: Eleven patients with type 2 diabetes were recruited. Patients spent the first day of the study without exercise (non-exercise day; NE day). In the second day, they walked at moderate-intensity (40% of the maximum heart rate reserve) for 15 min, 30 min after each meal (exercise day; E day). Glucose homeostasis was estimated by a continuous glucose monitor (CGM). All meals during the study were of standard composition. We compared NE day and E day concerning 24-h glucose homeostasis and 3 h postprandial glucose levels by the incremental area under the curve (iAUC) method. Medications were not changed during the study. RESULTS: The number of patients under basal supported oral therapy, intensive insulin therapy and oral hypoglycemic agents (OHA) were 5, 4 and 2, respectively. The blood glucose standard deviation over 24 h and the iAUC for the 24-h glycemic variability (NE day vs. E day; 34,765 [21,424-56,014] vs. 23,205 [15,323-39,779]) were smaller in E day than in NE day. CONCLUSION: These results suggest that postprandial moderate-intensity walking, easily performable in daily life activities, was effective for improving glucose homeostasis. Further study should be performed to clarify the relationship between postprandial walk and drug therapy (insulin and OHA), including insulin secretory ability.

Pseudo-aneurysm caused by stent fracture in the "sub-acute" phase after endovascular therapy for in-stent restenosis lesions.

Despite the reported favorable patency of stents in the treatment of femoropopliteal lesions, concern regarding stent fracture is increasing. Development of pseudo-aneurysm by stent fracture is rare and has been reported to occur in the chronic phase owing to mechanical fatigue. Here, we present the first report of a pseudo-aneurysm caused by stent fracture in the "sub-acute" phase after endovascular therapy for in-stent restenosis lesion. A 79-year-old man underwent endovascular therapy for an in-stent restenosis lesion of the right superficial femoral artery. Echography 48 days after the treatment showed a saccular pseudo-aneurysm at the proximal stent site, suggestive of stent fracture. Angiography confirmed the pseudo-aneurysm caused by stent fracture. A self-expandable endoluminal stent graft was deployed, which showed complete resolution of the pseudo-aneurysm. A pseudo-aneurysm caused by stent fracture can occur in the "sub-acute" phase after endovascular therapy for in-stent restenosis lesions. .

Remote Management of Pacemaker Patients With Biennial In-Clinic Evaluation: Continuous Home Monitoring in the Japanese At-Home Study: A Randomized Clinical Trial.

BACKGROUND: Current expert consensus recommends remote monitoring for cardiac implantable electronic devices, with at least annual in-office follow-up. We studied safety and resource consumption of exclusive remote follow-up (RFU) in pacemaker patients for 2 years. METHODS: In Japan, consecutive pacemaker patients committed to remote monitoring were randomized to either RFU or conventional in-office follow-up (conventional follow-up) at twice yearly intervals. RFU patients were only seen if indicated by remote monitoring. All returned to hospital after 2 years. The primary end point was a composite of death, stroke, or cardiovascular events requiring surgery, and the primary hypothesis was noninferiority with 5% margin. RESULTS: Of 1274 randomized patients (50.4% female, age 77±10 years), 558 (RFU) and 550 (Conventional follow-up) patients reached either the primary end point or 24 months follow-up. The primary end point occurred in 10.9% and 11.8%, respectively (P=0.0012 for noninferiority). The median (interquartile range) number of in-office follow-ups was 0.50 (0.50-0.63) in RFU and 2.01 (1.93-2.05) in conventional follow-up per patient-year (P<0.001). Insurance claims for follow-ups and directly related diagnostic procedures were 18 800 Yen (16 500-20 700 Yen) in RFU and 21 400 Yen (16 700-25 900 Yen) in conventional follow-up (P<0.001). Only 1.4% of remote follow-ups triggered an unscheduled in-office follow-up, and only 1.5% of scheduled in-office follow-ups were considered actionable. CONCLUSIONS: Replacing periodic in-office follow-ups with remote follow-ups for 2 years in pacemaker patients committed to remote monitoring does not increase the occurrence of major cardiovascular events and reduces resource consumption. Registration: URL: https://clinicaltrials.gov; Unique identifier: NCT01523704.

Interaction of platinum agents, cisplatin, carboplatin and oxaliplatin against albumin in vivo rats and in vitro study using inductively coupled plasma-mass spectrometory.

The protein binding rates (PBR) of platinum-containing agents cisplatin (CDDP), carboplatin (CBDCA) and oxaliplatin (L-OHP) have been reported as 98%, 25-50% and 98%, respectively. To investigate the protein-binding properties of albumin with cisplatin, carboplatin and oxaliplatin, inductively coupled plasma mass spectrometry (ICP-MS) was used to measure their plasma concentration in rats over time. The study also examined the effects of cisplatin, carboplatin and oxaliplatin-binding on albumin in vitro, using CD spectrometry and native-polyacrylamide gel electrophoresis (native PAGE). The ratios of PBR to irreversible PBR, of cisplatin and oxaliplatin were 98%:98% and 90%:87%, respectively, indicating a higher affinity for irreversible binding with albumin. That of carboplatin was 25%:10%, indicating 60-70% reversible binding with albumin. The plasma protein binding rate concentrations of cisplatin, carboplatin and oxaliplatin after in vivo administration were 96%, 15% and 80%, respectively. The CD spectrometry of albumin was unaffected by cisplatin, carboplatin and oxaliplatin binding. Though similar protein binding rates were observed with oxaliplatin and cisplatin, oxaliplatin had a higher mobility rate during PAGE. It was confirmed that the binding of cisplatin and oxaliplatin with albumin affected its electric charge but not the structure. In conclusion, cisplatin and oxaliplatin bind irreversibly with albumin in plasma and may irreversibly interact with tissue protein and/or DNA. The difficulties involved with predicting the tissue concentrations of cisplatin and oxaliplatin from their plasma concentration inhibits their therapeutic drug monitoring. On the contrary, carboplatin, like some generic drugs, reversibly binds to plasma proteins. It is, therefore, possible to conduct therapeutic drug monitoring for carboplatin.

Combined Use of Excimer Laser and High-Speed Rotational Atherectomy to Overcome a Severely Calcified Lesion in Endovascular Therapy.

Although endovascular therapy (EVT) is commonly used in treatment of peripheral artery disease (PAD), severely calcified lesions pose a challenge, in spite of the technical advancement. In this report, we discuss the case of a 74-year-old male with coronary artery disease and end-stage renal disease who presented at our institution with bilateral intermittent claudication. Angiography showed chronic total occlusion (CTO) of the right superficial femoral arteries (SFA). Because the bilateral external iliac arteries demonstrated moderate stenosis, we performed endovascular therapy on the right SFA-CTO using a contralateral approach. With the antegrade wire progressing into the subintimal space, direct distal-SFA puncture was performed and wire externalization was established. However, no devices (minimal balloon, microcatheter, or Crosser system) were able to pass the lesion in antegrade or retrograde manner, even though the child catheter support or needle cracking technique from outside/inside was applied. Therefore, we used a combination of an excimer laser and high-speed rotational atherectomy to overcome the severely calcified lesion. First, the excimer laser catheter (Turbo Elite 0.9 mm) ablated the entry to the CTO; however, it did not pass through completely. Thereafter, the thin microcatheter (Caravel) succeeded in crossing the CTO in an antegrade manner using the BAlloon Deployment using FORcible Manner (BADFORM) technique. After wire-exchange to the Rota-wire, rotational atherectomy (RotaLink Plus 1.5 mm) passed through the CTO. Subsequently, we could dilate the CTO lesion with a conventional balloon followed by bare metal stent deployment. The right ankle-brachial index of the patient improved from being unmeasurable to 0.79, and the intermittent claudication disappeared. This combination therapy, described as the "RASER" technique in coronary section, is accepted for reimbursement. However, these devices in EVT section are considered off-label use in Japan. Therefore, we have to refrain from frequent use of this strategy; however, this method provides an option for severely calcified lesions.

Simple percutaneous coronary interventions using the modification of complex coronary lesion with excimer laser.

Excimer laser coronary atherectomy (ELCA), a unique percutaneous coronary intervention (PCI) device, comprises a monorail-type system and is compatible with any standard 0.014-inch guidewire. ELCA is the only device that vaporizes the atherosclerotic plaques or modifies underlying plaque located underneath to a hard tissue, such as severe calcification or a stent. Therefore, ELCA differs from other coronary atherectomy devices and is useful for patients with acute coronary syndrome, chronic total occlusion or under-expanded stents. This case series reports on patients treated using ELCA to simplify complex PCI procedures. Furthermore, we review and discuss ELCA in several situations.

Single injection ion-exclusion/cation-exchange chromatography for simultaneous determination of organic/inorganic anions, inorganic cations, and ethanol in beer samples.

Multicomponent simultaneous analysis is important for management programs, which are required in beer industries because the beer constituents measure by combining several methods in the present. In response to a requirement, our research group developed single sample injection ion chromatography systems, which comprise ion-exclusion/cation-exchange chromatography (IEC/CEC) and post-column derivatization and show promise for simultaneously determining concentrations of organic and inorganic species and alcohol commonly found in beer. Optimal chromatographic resolutions for determining 17 different species in beer samples by IEC/CEC were obtained on a H+-formed weakly acidic cation-exchange resin column with an eluent comprising 2 mM phthalic acid and 1 mM 18-crown-6. Consequently, the usefulness of developed method for monitoring beer samples was demonstrated in terms of beneficial information such as dependency of K+ concentration on the malt amount, influences of organic anion concentrations on different types of bottling methods, and validation of ethanol concentrations displayed in the ingredient table.

The Wire Rendezvous and Chasing Wire Technique in the Bidirectional Approach for the Percutaneous Coronary Intervention for Chronic Total Occlusion with a Single Guiding Catheter.

A bidirectional approach for percutaneous coronary intervention for chronic total occlusion (CTO-PCI) using ipsilateral collaterals with a single guiding catheter limits procedural choices. The CTO of the left circumflex artery with ipsilateral collateral artery was treated by the bidirectional approach using a single guiding catheter. While the retrograde wire directly crossed the CTO lesion, the microcatheter could not pass the CTO lesion despite the conventional strategies. Therefore, we performed the wire rendezvous and chasing wire techniques. The wire rendezvous technique enables deeper retrograde guidewire progression, and the antegrade microcatheter can reach the CTO entry. The chasing wire technique enables the antegrade guidewire to pass the route made by the retrograde guidewire. These techniques might offer a possible solution for bidirectional CTO-PCI using a single guiding catheter. However, this technique should be considered as a last resort because of the risk of rapid reocclusion.

Contributions of caspase-8 and -9 to liver injury from CYP2E1-produced metabolites of halogenated hydrocarbons.

1. Drug-induced liver injury is difficult to predict at the pre-clinical stage. This study aimed to clarify the roles of caspase-8 and -9 in CYP2E1 metabolite-induced liver injury in both rats and cell cultures in vitro treated with carbon tetrachloride (CCl4), halothane or sevoflurane. The human hepatocarcinoma functional liver cell line was maintained in 3-dimensional culture alone or in co-culture with human acute monocytic leukemia cells. 2. In vivo, laboratory indices of liver dysfunction and histology were normal after administration of sevoflurane. CCl4 treatment increased blood AST/ALT levels, liver caspase-3 and -9 activities and liver malondialdehyde, accompanied by centrilobular hepatocyte necrosis. Halothane increased AST/ALT levels, caspase-3 and -8 activities (but not malondialdehyde) concomitant with widespread hepatotoxicity. In vitro, CCl4 treatment increased caspase-9 activity and decreased both mitochondrial membrane potential (MMP) and cell viability. In co-culture, halothane increased caspase-8 activity and decreased MMP and cellular viability. There were no toxic responses in CYP2E1 knockdown in monoculture and co-culture. 3. CYP2E1-inducing compounds play a pivotal role in halogenated hydrocarbon toxicity. 4. Changes in hepatocyte caspase-8 and -9 activities could be novel biomarkers of metabolites causing DILI, and in pre-clinical development of new pharmaceuticals can predict nascent DILI in the clinical stage.

The 1st step initiation essential for allergen-specific IgE antibody production upon the 2nd step: Induction of non-specific IgE+ small B cells containing secondly-sensitized allergen-specific ones in mice firstly-sensitized with an allergen.

There was a significant amount of non-specific, but not of allergen (e.g., papain, mite feces and four kinds of pollen)-specific, IgE antibodies (Abs) in the sera of normal mice. An i.n. injection of each allergen without adjuvant into mice caused an increase in total IgE Ab titers with a similar time course in the serum. However, the stage of initiation of allergy varied from allergen to allergen. Submandibular lymph node cells from normal mice contained papain-, but not mite feces- or pollen-specific IgE+ cells and an i.n. injection of papain induced papain-specific IgE Abs in the serum. In contrast, one (i.n.) or two (i.n. and s.c) injections of mite feces induced neither mite feces-specific IgE+ cells in the lymph nodes nor mite feces-specific IgE Abs in the serum. I.n. sensitization with cedar pollen induced cedar pollen-specific IgE+ small B cells in the lymph nodes on Day 10, when non-specific IgE Ab titers reached a peak in the serum, implying induction of related allergen-specific IgE+ small cells as well. In fact, a second (s.c.) injection of ragweed (or cedar) pollen into mice sensitized i.n. once with cedar (or ragweed) pollen, but not with mite feces, induced a large amount of ragweed (or cedar) pollen-specific IgE Abs in the serum. These results indicate that when firstly-sensitized non-specific IgE+ small B cells in mouse lymph nodes include some secondly-sensitized allergen-specific ones, mice produce IgE Abs specific for the secondly-injected allergen.

Utility of a 0.035″ compatible rapid-exchange balloon (Metacross RX™) as a perfusion balloon in endovascular therapy compared with conventional percutaneous coronary intervention: A mini-review.

Since endovascular treatment for peripheral artery disease has been rapidly and widely adopted as the preferred strategy, interventionists sometimes experience complications such as vessel perforation and severe dissections. We have a long-time inflation strategy for perfusion balloon catheters, which could be a solution for vessel complications in coronary sections, but not in peripheral sections. We invented a simple device for application as a perfusion balloon in peripheral sections, using a 0.035″ wire compatible rapid-exchange balloon Metacross RX™ (TERUMO, Tokyo, Japan) and reviewed this strategy using three cases as examples and compared them with the coronary perfusion balloon. TABLE OF CONTENTS SUMMARY: Metacross RX (TERUMO, Tokyo, Japan) is being used as a rapid exchange balloon and can be potentially used as a perfusion balloon. We report a series of cases in which patients were treated using the Metacross RX at a single-center for endovascular treatment of peripheral artery disease. We review and discuss the use of this device in comparison with the conventional coronary perfusion balloon catheter.

A novel lesion crossing technique: Balloon deployment using FORcible Manner (BADFORM) technique.

OBJECTIVES: We evaluated the efficacy and safety of a novel endovascular technique for crossing arterial lesions: The BAlloon Deployment using FORcible Manner (BADFORM) technique. BACKGROUND: Endovascular treatment (EVT) for peripheral artery disease has been widely adopted, and developments in device technology and techniques have resulted in acceptable success rates. However, it may be difficult to deliver devices even after wire externalization, especially in the presence of an extremely long chronic total occlusion or severely calcified lesion. The BADFORM technique might be useful in these cases. METHODS: We retrospectively reviewed ten consecutive EVT cases using the BADFORM technique performed at our institution between April 2015 and September 2016. In all cases, wire externalization was established with the rendezvous technique. The BADFORM technique was performed when antegrade passage of any device was impossible after wire externalization. Physicians positioned a low-profile balloon or microcatheter just proximal to the calcified lesion and attached the device to the externalized wire using a torque device at the proximal catheter exit port. The externalized wire was then pulled retrogradely. RESULTS: All patients were receiving hemodialysis and had critical limb ischemia. All lesions were severely calcified, and 90% were chronic total occlusions. The technical success and procedure success rates were 90% and 70%, respectively. Delivered devices included five balloon catheters and four microcatheters. One procedure-related vessel injury occurred at the distal puncture site (digital artery), however, this was controlled by external manual compression. CONCLUSIONS: The efficacy and safety of the BADFORM technique might be acceptable. © 2017 Wiley Periodicals, Inc.

A Novel Analytical Method of Cisplatin Using the HPLC with a Naphthylethyl Group Bonded with Silica Gel (πNAP) Column.

Cisplatin is the most widely used anticancer drug in the world. Mono-chloro and none-chloro complexes of cisplatin may be believed to be the activated compounds. The separation of these compounds using octa decyl silyl column or aminopropylsilyl silica gel column is difficult because of high-reactivity and structural similarity. In this study, cisplatin, hydroxo complexes, and OH-dimer were determined by HPLC using a naphthylethyl group bonded with silica gel (πNAP) column. The analytical conditions of HPLC were as follows: analytical column, πNAP column; wave length, 225 nm; column temperature, 40°C; mobile phase, 0.1 M sodium perchlorate, acetonitrile, and perchloric acid (290 : 10 : 3), flow rate, 1.0 mL/min. Sample (20 µL) was injected onto the HPLC system. Retention time of cisplatin, mono-chloride, OH-dimer, and none-chloride was 3.2, 3.4, 3.6, and, 4.3-6.6 min, respectively. Measurable ranges with this method were 1×10-5 to 4×10-3 M for cisplatin. Correlation coefficient of the calibration curves of cisplatin was 0.999 (p<0.01). The within- and between-day variations of coefficient of variation (CV) were 5% or lower. In this study, injectable formulations in physiological saline solution, water for injection, 5% glucose solution, and 7% sodium bicarbonate precisely were measured the stability and compositional changes upon mixing by πNAP column rather than C18 column. We successfully determined cisplatin, hydroxo complexes, and OH-dimer by HPLC using a πNAP column. Thus the measurement of cisplatin (cis-diamminedichloro-platinum(II), cis-[PtCl2(NH3)2]) (CDDP) should be done using a πNAP column rather than a C18 column or aminopropylsilyl silica gel column.

False Prolongation of Prothrombin Time in the Presence of a High Blood Concentration of Daptomycin.

Prothrombin time (PT) can reportedly be falsely prolonged by the antimicrobial drug daptomycin (DAP), and concomitant use of phosphatidylglycerol (PG). Although high doses of DAP (>6 mg/kg/day) are recommended for severe infection and result in a high blood concentration, the extent to which high blood concentrations of DAP interfere with PT, in the presence or absence of PG, has yet to be determined when using the HemosIL RecombiPlasTin 2G (Werfen Japan, Tokyo, Japan). We examined the effects of high doses of DAP on PT using this reagent. DAP (0-500 mg/L) was added to normal plasma and plasma with an already prolonged PT in the presence or absence of liposomal amphotericin B (L-AMB, 5-50 mg/L) or COATSOME EL-01 empty cationic liposomes (CS, 25-250 mg/L). Furthermore, we undertook a Monte Carlo simulation to calculate the probability of achieving DAP concentrations >100, >200 and >500 mg/L 0-48 hr after administering 6-12 mg/kg of DAP. Apparent PT increased with increasing DAP concentration, but neither L-AMB nor CS appeared to further elevate PT when co-administered with DAP. The probability of achieving DAP concentrations >100 and >200 mg/L increased with DAP dose. Higher doses of DAP than the approved dose caused false prolongation of PT. PT should be monitored carefully in patients taking high doses of DAP; ideally, PT should be measured at the trough blood concentration of DAP. Concomitant use of L-AMB and CS did not generally further elevate PT when co-administered with DAP.