Population pharmacokinetic simulation of varied Immune Globulin Subcutaneous (Human), 20% solution (Ig20Gly) loading and maintenance dosing regimens in immunoglobulin-naïve patients with primary immunodeficiency diseases.

Background: The pharmacokinetics of Ig20Gly, a 20% subcutaneous immunoglobulin (IG) therapy, is well characterized in IG-experienced patients with primary immunodeficiency diseases (PID). Data from IG-naïve patients are limited.

Objective: Simulate serum total immunoglobulin G (IgG) pharmacokinetic profiles in IG-naïve patients with PID for different Ig20Gly initiation and maintenance dosing regimens.

Population Pharmacokinetic Model Development and Simulation for Recombinant Erwinia Asparaginase Produced in Pseudomonas fluorescens (JZP-458).

JZP-458 is a recombinant Erwinia asparaginase produced using a novel Pseudomonas fluorescens expression platform that yields an enzyme expected to lack immunologic cross-reactivity to Escherichia coli-derived asparaginases. It is being developed as part of a multiagent chemotherapeutic regimen to treat acute lymphoblastic leukemia or lymphoblastic lymphoma patients who develop E coli-derived asparaginase hypersensitivity. A population pharmacokinetic (PopPK) model was developed for JZP-458 using serum asparaginase activity (SAA) data from a phase 1, single-dose study (JZP458-101) in healthy adults.

Population pharmacokinetic modeling and simulation of immunoglobulin exposure with varying dosing intervals of subcutaneous immunoglobulin 20% (Ig20Gly) in patients with primary immunodeficiency diseases.

Background: Immunoglobulin (IG) replacement therapy in patients with primary immunodeficiency diseases (PID) can be administered daily to every 2 weeks subcutaneously (SCIG) or every 3 or 4 weeks intravenously (IVIG).

Objectives: Develop a population pharmacokinetic (PK) model simulating IG exposure with Ig20Gly, a 20% SCIG; determine the dose adjustment factor for Ig20Gly relative to IVIG.

Methods: Data from patients with PID treated with Ig20Gly and IVIG 10% were used to characterize IG population PK by nonlinear mixed-effects modeling and validated using data splitting and a visual predictive check.

Warfarin dosing and the promise of pharmacogenomics.

Due to its narrow therapeutic index and substantial inter-patient variability in clinical response, warfarin represents an ideal drug candidate to benefit from the promise of pharmacogenomic-guided dosing strategies. Consistent with in vitro data, clinical studies have demonstrated that CYP2C9 polymorphisms significantly influence warfarin pharmacokinetics by reducing (S)-warfarin metabolic clearance, consequently lowering maintenance dose requirements and increasing the risk over-anticoagulation during the initiation phase of therapy. Recent data suggest that polymorphisms in genes encoding several pharmacodynamic determinants of the coagulation cascade may also influence warfarin's antithrombotic dose-response.

Pharmacokinetics and metabolic profile of free, conjugated, and total silymarin flavonolignans in human plasma after oral administration of milk thistle extract.

Silymarin, a mixture of polyphenolic flavonoids extracted from milk thistle (Silybum marianum), is composed mainly of silychristin, silydianin, silybin A, silybin B (SB(B)), isosilybin A (ISB(A)), and isosilybin B. In this study, the plasma concentrations of free (unconjugated), conjugated (sulfated and glucuronidated), and total (free and conjugated) silymarin flavonolignans were measured using liquid chromatography-electrospray ionization-mass spectrometry, after a single oral dose of 600 mg of standardized milk thistle extracts to three healthy volunteers. Pharmacokinetic analysis indicated that silymarin flavonolignans were rapidly eliminated with short half-lives (1-3 and 3-8 h for free and conjugated, respectively).