Liver Fibrosis Stages Affect Organic Cation Transporter 1/2 Activities in Hepatitis C Virus-Infected Patients.

This study aims to evaluate the impact of liver fibrosis stages of chronic infection with hepatitis C virus (HCV) on the in vivo activity of organic cation transporters (hepatic OCT1 and renal OCT2) using metformin (MET) as a probe drug. Participants allocated in Group 1 ( = 15, mild to moderate liver fibrosis) or 2 ( = 13, advanced liver fibrosis and cirrhosis) received a single MET 50 mg oral dose before direct-acting antiviral (DAA) drug treatment (Phase 1) and 30 days after achieving sustained virologic response (Phase 2). OCT1/2 activity (MET AUC) was found to be reduced by 25% when comparing the two groups in Phase 2 (ratio 0.

Clinical treatment for hepatitis C reverses CYP2C19 inhibition.

Aims: Infection by the hepatitis C virus (HCV) generates inflammatory response selectively modulating cytochrome P450 protein (CYP) activities. This study assessed the effect of chronic hepatitis C on CYP2C19 activity in patients with HCV.

Methods: Patients with HCV infection (n = 23) at different fibrosis stages were allocated into groups 1 (F0/F1 and F2, mild to moderate fibrosis) and 2 (F3 and F4, advanced fibrosis stages).

Rheumatoid arthritis downregulates the drug transporter OATP1B1: Fluvastatin as a probe.

Aims: Rheumatoid arthritis (RA) is a long term autoimmune inflammatory disease characterized by high autoantibody production and cytokine release, especially IL-6 and TNF-α. Some clinical studies have shown the effect of RA on CYP metabolism. However, the effect of RA on the drug transporter OATP1B1 remains a gap.

Plasma mevalonic acid exposure as a pharmacodynamic biomarker of fluvastatin/atorvastatin in healthy volunteers.

Fluvastatin and atorvastatin are inhibitors of hydroxy-methylglutaryl-CoA (HMG-CoA) reductase, the enzyme that converts HMG-CoA to mevalonic acid (MVA). The present study reports for the first time the analysis of mevalonolactone (MVL) in plasma samples by UPLC-MS/MS as well as the use of MVA, analyzed as MVL, as a pharmacodynamics parameter of fluvastatin in multiple oral doses (20, 40 or 80 mg/day for 7 days) and atorvastatin in a single oral dose (20, 40 or 80 mg) in healthy female volunteers. this study presents the use of MVL exposure as a pharmacodynamics biomarker of fluvastatin in multiple oral doses (20, 40 or 80 mg/day for 7 days) or atorvastatin in a single oral dose (20, 40 or 80 mg) in healthy volunteers (n = 30).

The development of a new disposable pipette extraction phase based on polyaniline composites for the determination of levels of antidepressants in plasma samples.

In the present work, a new stationary phase for disposable pipette extraction (DPX) based on composites of polyaniline and a styrene-divinylbenzene (SD) copolymer was applied to the analysis of fluoxetine and norfluoxetine in plasma samples using liquid chromatography and fluorescence detector (LC-FD). The DPX variables, such as number of draw/eject cycles, sample pH, type and volume of the desorption solvent, were optimized to established the sorption equilibrium and shorten the analysis time. Among the DPX evaluated variables, the higher extraction efficiency were obtained with 200 μL of plasma mixed with 200 μL of borate solution (pH 9), followed by liquid desorption of the drug with 200 μL acetonitrile in a single cycle.

Automated analysis of lidocaine and its metabolite in plasma by in-tube solid-phase microextraction coupled with LC-UV for pharmacokinetic study.

A sensitive, selective, and reproducible in-tube solid-phase microextraction and liquid chromatographic (in-tube SPME/LC-UV) method for determination of lidocaine and its metabolite monoethylglycinexylidide (MEGX) in human plasma has been developed, validated, and further applied to pharmacokinetic study in pregnant women with gestational diabetes mellitus (GDM) subjected to epidural anesthesia. Important factors in the optimization of in-tube SPME performance are discussed, including the draw/eject sample volume, draw/eject cycle number, draw/eject flow rate, sample pH, and influence of plasma proteins. The limits of quantification of the in-tube SPME/LC method were 50 ng/mL for both metabolite and lidocaine.