Assays for Monitoring Apixaban and Rivaroxaban in Emergency Settings, State-of-the-Art Routine Analysis, and Volumetric Absorptive Microsamples Deliver Discordant Results
Fehér et al.
The finding, in our words
The paper found that two laboratory assays for the anticoagulants apixaban and rivaroxaban gave markedly different plasma concentrations, and that dried blood volumetric absorptive microsamples taken by patients at home did not agree with plasma results. For decentralised diagnostics this means clinical laboratories must validate their chosen method and always measure haematocrit when using microsamples to ensure accurate anticoagulant monitoring.
A paraphrase to the Library’s standard, never the abstract. The source is one link away and is always the authority.
In AML and CLL, 91% of VAMS venetoclax results fell within 20% of plasma after individualised haematocrit correction; in home sampling, 18 of 21 patients self-sampled independently and 76% of returned samples were analysable, which shows home microsampling is workable, though the authors ask for multicentre validation.
Levens et al., Clinical Pharmacokinetics (paywalled) · source ↗
In lung and renal transplant recipients, VAMS sampling with LC-MS/MS quantification of mycophenolic acid and tacrolimus showed good linearity and accuracy, and with a haematocrit-adjusted conversion formula achieved clinical agreement in most samples; tacrolimus did not require haematocrit correction. The approach is virtually painless and enables richer sampling for more accurate drug exposure estimates, supporting decentralised therapeutic drug monitoring.
Juan et al., Journal of pharmacy & pharmaceutical sciences : a publication of the Canadian Society for Pharmaceutical Sciences, Societe canadienne des sciences pharmaceutiques · source ↗
This review found that volumetric microsampling devices, such as Mitra, HemaPEN, HemaXis DB10, and Tasso-M20, overcome haematocrit bias, whilst Telimmune plasma separation cards enable direct plasma collection without centrifugation. These technologies support patient-centric, decentralised sampling, though the authors note that clinical validation remains limited across different drugs and patient populations.
Huhn & Scherf-Clavel, Therapeutic drug monitoring (paywalled) · source ↗
The study validated an LC-MS/MS method for eight antiepileptic drugs and two metabolites in dried blood spot and VAMS formats, with satisfactory analytical performance and stability, and was the first to include the oxcarbazepine metabolite DHCB. In 80 paired patient samples, microsampling concentrations showed promising correlation with plasma, supporting decentralised therapeutic drug monitoring of antiepileptic treatment.
Cobo-Golpe et al., Journal of analytical toxicology · source ↗
The study developed and validated a rapid LC-MS/MS method for quantifying cefazolin in capillary whole blood collected via VAMS, plasma, and plasma ultrafiltrate, showing robust performance across matrices and successful application in a pediatric pilot cohort for therapeutic drug monitoring.
Kocur et al., Clinica chimica acta; international journal of clinical chemistry (paywalled) · source ↗