Pharmacokinetics and Pharmacodynamics of Once-Daily Tacrolimus Compared With Twice-Daily Tacrolimus in the Early Stage After Living Donor Liver Transplantation.

Background: This study investigates the pharmacokinetics and pharmacodynamics of tacrolimus using the once-daily (OD) formulation in the early stage after living donor liver transplantation (LDLT) in comparison with those using the twice-daily (TD) formulation.

Methods: Nine patients undergoing primary LDLT and treated with the OD tacrolimus formulation were included. The trough blood concentration (C0) of tacrolimus was monitored every day for 3 weeks after LDLT.

Population Pharmacokinetic Modeling of Levetiracetam in Pediatric and Adult Patients With Epilepsy by Using Routinely Monitored Data.

Background: Levetiracetam, a second-generation antiepileptic drug, is frequently used for managing partial-onset seizures. About 70% of the administered dose is excreted in urine unchanged, and dosage adjustment is recommended based on the individual's renal function. In this study, a population pharmacokinetic model of levetiracetam was developed using routinely monitored serum concentration data for individualized levetiracetam therapy.

Sensitive and validated LC-MS/MS methods to evaluate mycophenolic acid pharmacokinetics and pharmacodynamics in hematopoietic stem cell transplant patients.

Monitoring of pharmacodynamics in addition to pharmacokinetics is one of strategies to individualize mycophenolate mofetil therapy. The purpose of this study was to develop sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods for evaluation of the pharmacokinetics and pharmacodynamics of mycophenolic acid (MPA). Concentrations of mycophenolic acid glucuronide (MPAG), mycophenolic acid acyl-glucuronide, as well as unbound MPA and MPAG, were determined, and inosine-5'-monophosphate dehydrogenase activity was calculated by measuring concentrations of produced xanthosine-5'-monophosphate (XMP) and intracellular adenosine-5'-monophosphate after incubation of peripheral blood mononuclear cell (PBMC) lysates.

Effect of CYP2C19 polymorphisms on the clinical outcome of low-dose clobazam therapy in Japanese patients with epilepsy.

Purpose: Clobazam (CLB) is metabolized by cytochrome P450 (CYP) 3A4 to yield N-desmethylclobazam (N-CLB), which is further inactivated by CYP2C19. The aim of this study was to retrospectively evaluate the relationship between CYP2C19 polymorphisms and the efficacy of low-dose, add-on CLB therapy in Japanese patients with epilepsy.

Methods: Fifty patients were divided into three groups according to their CYP2C19 polymorphism.

Successful telaprevir treatment in combination of cyclosporine against recurrence of hepatitis C in the Japanese liver transplant patients.

Telaprevir (TVR) is a protease inhibitor used in combination with pegylated interferon alfa-2b and ribavirin for hepatitis C, and TVR strongly inhibits CYP3A4 and CYP3A5. We reported successful TVR treatment of liver transplant patients with recurrence of hepatitis C during receiving immunosuppressive therapy. Before initiation of triple therapy, all patients switched from tacrolimus to cyclosporine, which has a lower inhibitory effect on CYP3A4 and CYP3A5 than tacrolimus.

Association between CYP3A5 genotypes in graft liver and increase in tacrolimus biotransformation from steroid treatment in living-donor liver transplant patients.

  We retrospectively examined whether cytochrome P450 (CYP) 3A5 genotypes are associated with high-dose steroid pulse treatment-induced functional gain of tacrolimus biotransformation in living-donor liver transplant patients. Concentrations of tacrolimus and its 3 primary metabolites, 13-O-demethyl tacrolimus (M-I), 31-O-demethyl tacrolimus (M-II), and 15-O-demethyl tacrolimus (M-III), were measured in trough blood samples from 18 liver transplant patients, by liquid chromatography-tandem mass spectrometry/mass spectrometry (LC-MS/MS). In patients engrafted with a CYP3A5*1-carrying liver but not with a CYP3A5*3/*3-carrying liver, the concentration/dose ratio of tacrolimus significantly fell after therapy, while ratios of M-I/tacrolimus, M-II/tacrolimus, and M-III/tacrolimus were significantly higher after therapy than before (p = 0.

Effectiveness of sirolimus in combination with cyclosporine against chronic rejection in a pediatric liver transplant patient.

The patient is a 3-year-old boy who received living-donor liver transplantation (LDLT) for hepatoblastoma, with his mother as the donor. Oral tacrolimus was started at a dose of 0.3 mg every 12 h from day 1, with the dosage adjusted on the basis of trough concentrations.

Detection of 22 antiepileptic drugs by ultra-performance liquid chromatography coupled with tandem mass spectrometry applicable to routine therapeutic drug monitoring.

The purpose of this study was to develop an ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method of 22 antiepileptics for routine therapeutic monitoring. The antiepileptics used in the analyses were carbamazepine, carbamazepine-10,11-epoxide, clobazam, N-desmethylclobazam, clonazepam, diazepam, N-desmethyldiazepam, ethosuximide, felbamate, gabapentin, lamotrigine, levetiracetam, N-desmethylmesuximide, nitrazepam, phenobarbital, phenytoin, primidone, tiagabine, topiramate, valproic acid, vigabatrin and zonisamide. After protein precipitation of 50 μL plasma with methanol, the supernatant was diluted with water or was evaporated to dryness and reconstituted with mobile phase in the case of benzodiazepines.

Significance of trough monitoring for tacrolimus blood concentration and calcineurin activity in adult patients undergoing primary living-donor liver transplantation.

Purpose: Tacrolimus pharmacokinetics and calcineurin activity in peripheral blood mononuclear cells (PBMCs) were investigated in adult patients undergoing primary living-donor liver transplantation (LDLT) in order to clarify the significance of monitoring the tacrolimus blood trough concentration during the early post-transplantation period.

Methods: Fourteen patients were enrolled in this study, and time-course data following the oral administration of a conventional tacrolimus formulation twice daily were obtained at 1 and 3 weeks post-transplantation. The concentration of tacrolimus in whole blood and calcineurin activity in PBMCs were measured.