Longitudinal Monitoring of Hair Cortisol Using Liquid Chromatography-Mass Spectrometry to Prevent Hypercortisolism in Patients Undergoing Glucocorticoid Replacement Therapy.

Objective: Currently available methods for endogenous cortisol monitoring in patients with hormonal insufficiency rely on measurements of plasma levels only at a single time point; thus, any kind of chronic exposure to cortisol is challenging to evaluate because it requires collecting samples at different time points. Hair cortisol levels acquired longitudinally better reflected chronic exposure (both cortisol synthesis and deposition) and may significantly contribute to better outcomes in glucocorticoid replacement therapies.

Design: Twenty-two patients on cortisol substitution therapy were monitored for plasma, urinary, and hair cortisol levels for 18 months to determine whether hair cortisol may serve as a monitoring option for therapy setting and adjustment.

Therapeutic Drug Monitoring of Sunitinib in Gastrointestinal Stromal Tumors and Metastatic Renal Cell Carcinoma in Adults-A Review.

Background: Sunitinib is an inhibitor of multiple receptor tyrosine kinases and is a standard-of-care treatment for advanced and metastatic renal cell carcinoma and a second-line treatment in locally advanced inoperable and metastatic gastrointestinal stromal tumors. A fixed dose of the drug, however, does not produce a uniform therapeutic outcome in all patients, and many face adverse effects and/or toxicity. One of the possible causes of the interindividual variability in the efficacy and toxicity response is the highly variable systemic exposure to sunitinib and its active metabolite.