Evaluation of the clinical and quantitative performance of a practical HPLC-UV platform for in-hospital routine therapeutic drug monitoring of multiple drugs.

BACKGROUND: In-hospital therapeutic drug monitoring (TDM) requires a suitable quantification method for target drugs from the viewpoint of precision, throughput, and testing costs. We previously developed a practical HPLC-UV platform for quantification of serum levels of various drugs. In this report, the platform was effectively applied to the quantification of patient serum levels of five different drugs by clinical professionals in our hospital during their daily work. METHODS: The residual sera of patients receiving carbamazepine (CBZ), phenytoin (PHT), lamotrigine (LTG), vancomycin (VCM), or voriconazole (VRCZ) were used in the present clinical study. The quantification method for each drug consisted of rapid solid-phase extraction (SPE) of each drug in the patient serum, followed by optimized HPLC-UV analysis of the drug in the SPE eluate. Furthermore, patient serum levels of PHT, CBZ, and VCM were also measured by ligand-binding assay using a cobas® analyzer in our hospital, and those of LTG and VRCZ were measured by HPLC-MS/MS at an outsourced provider. Passing-Bablok regression analysis and Bland-Altman analysis were employed to analyze the agreement of drug levels in patient sera, which was separately quantified using two different methods-our HPLC-UV platform and the cobas analyzer, or HPLC-UV and HPLC-MS/MS. RESULTS: All analytical conditions of the present method using our HPLC-UV platform were well optimized for each target drug quantification in the patient's serum, and the quantification method for each drug was fully validated for accuracy, precision and reproducibility. Furthermore, Passing-Bablok regression analysis and Bland-Altman analysis revealed that patient serum levels of PHT, CBZ, and VCM quantified by our HPLC-UV platform were closely correlated with those quantified by the cobas® analyzer, and the levels of LTG and VRCZ quantified by our HPLC-UV platform were also correlated with those quantified by HPLC-MS/MS. CONCLUSIONS: Our HPLC-UV platform can be performed without requiring special analytical techniques. This platform is expected to be used for the measurement of blood levels of multiple drugs for in-hospital routine TDM.

Elevated blood favipiravir levels are inversely associated with ferritin levels and induce the elevation of uric acid levels in COVID-19 treatment: A retrospective single-center study.

INTRODUCTION: Measurement of blood Favipiravir (FPV) levels and accumulation of data in COVID-19 patients are critical for assessing FPV efficacy and safety. We performed a retrospective study based on measurements of blood levels of FPV and related factors in COVID-19 patients admitted to our hospital. Furthermore, we also investigated the association between blood FPV levels and uric acid level alterations before and after FPV administration. METHODS: We enrolled 27 COVID-19 patients who had received FPV treatment at Hokushin General Hospital from April 1 to December 31, 2020. Age, gender, COVID-19 severity, presence of comorbidities, and laboratory data for each subject were investigated to identify factors that correlate with blood FPV levels. Uric acid levels were measured before and after FPV administration and a difference between the levels (i.e., a change of uric acid level) was evaluated. RESULTS: When a significant univariate variable was input by the stepwise method and a combination of variables that maintained statistical superiority was searched, serum ferritin was the only factor that independently affected blood FPV level. Furthermore, in the high-FPV group (20 µg/mL or more), a significant increase in uric acid levels was observed after FPV administration. The increment value was significantly larger than that in the low-FPV group (less than 20 µg/mL). CONCLUSIONS: Ferritin level was an important independent factor inversely affecting blood FPV level. Furthermore, a high blood FPV level induced the elevation of uric acid levels in COVID-19 treatment.

Optimization of Analytical Procedure for In-hospital Rapid Quantification of Serum Level of Favipiravir in the Pharmacological Treatment of COVID-19.

An in-hospital rapid method for quantifying the serum level of favipiravir (FPV) in the pharmacological treatment of COVID-19 was developed by an appropriate combination of a solid-phase extraction treatment and a reversed-phase HPLC/UV detection system. The quantification method was well-validated and applied to measuring the serum FPV level in a clinical practice at a general hospital that accepts COVID-19 patients. Furthermore, an analysis of data from our preliminary interaction analysis revealed, for the first time, that FPV selectively forms complexes with ferric (Fe3+) and cupric (Cu2+) ions.

[A Clinical Pathway Based on Medical and Nursing Teamwork in Drug Management Facilitates Integrated Community Care for Elderly Patients with Chronic Heart Failure].

　Chronic heart failure (CHF) is a critical disease in the aging population. Conventional therapy in hospitals cannot cure elderly patients with CHF at the end of life. Patients and their families experience anxiety and need comfortable care at home or in a nursing facility. To improve chronic cardiovascular disease management, we developed a simplified but integrated clinical pathway to facilitate medical and nursing care teamwork in the local community. Our institution is a central hospital in the North Shinshu district, which has an approximate population of 100000. We developed a pathway for both clinical program and information provision between our hospital and neighboring clinics. A hospital team evaluates and shares patient information with a homecare medical team every 6 months using the medical staff pathway. To maintain the efficacy and security of pharmacotherapy, a hospital clinical pharmacist reviews the prescriptions and prepares a drug profile book to share drug information between patients and all medical staff. These efforts have resulted in preventing adverse effects of drugs and reduced the cost of medications. Physical activity evaluation and nutrient guidance are also useful for patients to maintain their personal lifestyles. We initiated use of the pathway from 2009 and have followed up over 500 patients since then. We have also established a community partnership council to promote face-to-face communication among multiple categories of institutions and government agencies. Members of the council collaborate to help patients with cardiovascular disease to manage their own lives at home.

High-throughput determination of octanol/water partition coefficients using a shake-flask method and novel two-phase solvent system.

A high-throughput method for determining the octanol/water partition coefficient (P(o/w)) of a large variety of compounds exhibiting a wide range in hydrophobicity was established. The method combines a simple shake-flask method with a novel two-phase solvent system comprising an acetonitrile-phosphate buffer (0.1 M, pH 7.4)-1-octanol (25:25:4, v/v/v; AN system). The AN system partition coefficients (K(AN)) of 51 standard compounds for which log P(o/w) (at pH 7.4; log D) values had been reported were determined by single two-phase partitioning in test tubes, followed by measurement of the solute concentration in both phases using an automatic flow injection-ultraviolet detection system. The log K(AN) values were closely related to reported log D values, and the relationship could be expressed by the following linear regression equation: log D=2.8630 log K(AN) -0.1497(n=51). The relationship reveals that log D values (+8 to -8) for a large variety of highly hydrophobic and/or hydrophilic compounds can be estimated indirectly from the narrow range of log K(AN) values (+3 to -3) determined using the present method. Furthermore, log K(AN) values for highly polar compounds for which no log D values have been reported, such as amino acids, peptides, proteins, nucleosides, and nucleotides, can be estimated using the present method. The wide-ranging log D values (+5.9 to -7.5) of these molecules were estimated for the first time from their log K(AN) values and the above regression equation.

[Study of blood concentration analysis for formate in acute methanol poisoning].

A 53-year-old woman ingested about 300 mL of 95% methanol. After immediate ethanol antagonist therapy and hemodialysis, she recovered completely. Few days later, the plasma concentration of methanol and formate was measured. A gas chromatography was used for the plasma methanol concentration measurement, and a colorimetric method was used for plasma formate concentration measurement (Formate Colorimetric Assay Kit; BioVision, California, USA). Patient's plasma methanol concentration before hemodialysis was 676.9 mg/dL and plasma formate concentration was 16.9 mg/dL. By removing blood methanol and formate using hemodialysis before formate accumulations in the body, the patient was discharged without any sequelae. We were able to obtain correlation between a gas chromatography and colorimetric method without gas chromatography-mass spectrometry, with good correlation coefficients. The sensitivity was sufficient for analyzing blood sample. Monitoring formate concentration is useful in determining the treatment and evaluating the prognosis of methanol poisoning. We suggest that this colorimetric method is useful in a facility with no access to a gas chromatography in order to measure a plasma formate concentration.

[Life-Threatening Hyponatremia by Chemotherapy in a Patient with Non-Hodgkin's Lymphoma].

Cyclophosphamide and vincristine are known to be the chemotherapeutic agents most frequently associated with hyponatremia. Here, we report the case of a 69-year-old man with non-Hodgkin's lymphoma who developed severe hyponatremia during chemotherapy. The Japanese man was diagnosed with diffuse large B-cell lymphoma, and underwent chemotherapy treatment with THP-COP (cyclophosphamide, pirarubicin, vincristine, and prednisolone). In the first course of chemotherapy, he developed hyponatremia (nadir 109 mEq/L) and his urinary N-acetyl-ß-D-glucosaminidase (NAG) level had increased. After the second courses of chemotherapy with rituximab, pirarubicin, and prednisolone, without cyclophosphamide and vincristine, he had developed light hyponatremia (nadir 130 mEq/L). However, after the third and fourth courses of chemotherapy with rituximab, pirarubicin, prednisolone, and cyclophosphamide, he had developed a medium level of hyponatremia (nadir 124-125 mEq/L) and his NAG level had increased further. The possible mechanism of this phenomenon is due to renal tubular damage by cyclophosphamide. We conclude that extra caution is necessary if a patient develops severe hyponatremia following chemotherapeutic treatment with cyclophosphamide and vincristine.

Counter-Current Chromatographic Separation of Nucleic Acid Constituents with a Polar Volatile Organic-Aqueous Two-Phase Solvent Systems with ELSD Detection.

Highly hydrophilic volatile organic/aqueous two-phase solvent systems containing an organic salt such as, acetonitrile/800 mM and 1200 mM ammonium acetate (1 : 1, v/v) were efficiently utilized for high-speed counter-current chromatography (HSCCC) to separate hydrophilic compounds. The retention of the upper and the lower stationary phases in the column of the cross-axis coil planet centrifuge (CCC instrument) was studied by changing the flow-rate of the mobile phase (1.0-3.0 ml/min). Using the acetonitrile/800 mM ammonium acetate two-phase solvent system, the stationary phase was retained at 46.3% relative to the total column capacity of 65 ml by the reversed-phase elution mode at a flow-rate of 1.0 ml/min. The best retention of the stationary upper phase of 51.5% was obtained by the solvent system of the acetonitrile/1200 mM ammonium acetate at the above flow-rate. With the acetonitrile/800 mM ammonium acetate system the base line separation of adenine and adenosine monophosphate (AMP) detected by evaporative light scattering detector (ELSD) and UV was achieved with lower phase mobile at a flow-rate of 1.0 ml/min within 70 min.