2024 · Journal of pharmaceutical and biomedical analysis · paywalled
Fingerprick volumetric absorptive microsampling for therapeutic drug monitoring of antiseizure medications: Reliability and real-life feasibility in epilepsy patients
Cancellerini et al.
The finding, in our words
A study of 301 adults with epilepsy providing 464 measurements found that patient-centric capillary VAMS microsampling showed good agreement with plasma for seven of 13 antiseizure medicines, such as carbamazepine and levetiracetam. However, systematic differences remained for valproate, primidone, topiramate, and zonisamide, meaning decentralised monitoring is feasible for most but some drugs need further evaluation.
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 ↗
At-home volumetric absorptive microsampling (VAMS) for anti-seizure medicines was feasible and reliable, with strong correlations to clinic VAMS and low bias for lacosamide, lamotrigine and levetiracetam; quantitative dried blood spot (qDBS) was a reliable alternative in the ambulatory setting, though older age reduced sampling quality.
Cancellerini et al., Epilepsia (paywalled) · source ↗
This study established conversion methods for estimating plasma concentrations from whole blood VAMS samples for seven out of ten oral anticancer drugs, finding good agreement between capillary and venous samples. Patients reported a positive experience with home sampling using this microsampling technique.
Meertens et al., Therapeutic drug monitoring · source ↗
Microsampling, particularly VAMS and quantitative DBS, can enable patient-centric therapeutic drug monitoring of immunosuppressants after transplantation, allowing home self-sampling and long-term monitoring when patients live far from transplant centres. These volumetric dried formats have largely overcome the haematocrit effect and sample heterogeneity that limit conventional dried blood spots.
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.