Patiromer Does Not Alter Tacrolimus Pharmacokinetics in Kidney Transplant Recipients When Administered Three Hours Post-Tacrolimus.

Background: Hyperkalemia is common in kidney transplant (KTx) recipients. Patiromer, a potassium-binding polymer used to treat acute and chronic hyperkalemia, has the potential to bind charged particles in the gastrointestinal tract and thereby potentially affect the absorption of coadministered drugs. The immunosuppressive drug tacrolimus (Tac) has a narrow therapeutic window, is susceptible to drug-drug interactions (DDIs), and a potential gastrointestinal interaction with patiromer could elevate the risk of allograft rejection.

Multiscale Responsive Kinetic Modeling: Quantifying Biomolecular Reaction Flux under Varying Electrochemical Conditions.

Attaining a complete thermodynamic and kinetic characterization for processes involving multiple interconnected rare-event transitions remains a central challenge in molecular biophysics. This challenge is amplified when the process must be understood under a range of reaction conditions. Herein, we present a novel condition-responsive kinetic modeling framework that can combine the strengths of bottom-up rate quantification from multiscale simulations with top-down solution refinement using both equilibrium and nonequilibrium experimental data.

A Urine pH-Ammonium Acid/Base Score and CKD Progression.

Key Points: This study developed a urine acid/base score to assess tubular acid excretion capacity and identify early acid retention in CKD. The results show that early signs of acid retention (a low acid/base score) are associated with a higher risk for CKD progression. Future research should address if a low urine acid/base score can be improved and if this translates into clinically meaningful effects.

Nernst equilibrium, rectification, and saturation: Insights into ion channel behavior.

The dissipation of electrochemical gradients through ion channels plays a central role in biology. Herein we use voltage-responsive kinetic models of ion channels to explore how electrical and chemical potentials differentially influence ion transport properties. These models demonstrate how electrically driven flux is greater than the Nernstian equivalent chemically driven flux yet still perfectly cancels when the two gradients oppose each other.