2017 · The Journal of clinical psychiatry · paywalled
Dried Blood Spot Analysis for Therapeutic Drug Monitoring of Clozapine
Geers et al.
The finding, in our words
Finger-prick dried blood spot sampling demonstrates good agreement with plasma for therapeutic drug monitoring of clozapine and norclozapine, with haematocrit showing no significant influence on results. The method is stable for two weeks at room temperature and two years frozen, offering a reliable approach for patient-centric monitoring of clozapine therapy.
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 matched clinical samples from rheumatoid arthritis, VAMS and DBS showed strong agreement for methotrexate polyglutamates (slopes 0.95-1.07; bias within -4.21% to 0.36%; SRCC ≥ 0.969), with up to 100% of total MTXPG results within ±20% limits; capillary microsampling agreed closely with whole blood but differed from red blood cells, indicating matrix-specific differences that must be accounted for when interpreting against RBC-based reference values.
Kocur et al., International journal of molecular sciences · source ↗
The study found a dried blood spot method for ustekinumab was linear from 3 to 12 mg/L with inter-day accuracy of 90.1 to 106%, enabling reliable capillary blood measurement for remote monitoring; the authors note the single-centre design.
A 2025 review maps 28 microsampling devices, from dried spots and volumetric absorptive tips to upper-arm liquid capillary collectors, and names what a laboratory must control before their results are used: the haematocrit effect in non-volumetric dried samples, interstitial fluid from finger milking, volume, haemolysis and transport stability. Regulators on both sides of the Atlantic ask for the same two things, a device the patient can use safely and a sample fit for the test.
LC-MS/MS measurement of imatinib and its active metabolite from volumetric dried blood spots collected via HemaXis DB10 and Capitainer B demonstrated analytical precision across hematocrits from 22% to 55% alongside 43-day ambient stability. Clinical evaluation across 52 paired samples showed high agreement with plasma concentrations, verifying both devices as reliable options for decentralised therapeutic drug monitoring.
Orleni et al., Journal of chromatography. B, Analytical technologies in the biomedical and life sciences (paywalled) · source ↗