Volumetric Absorptive Microsampling (VAMS) for Therapeutic Drug Monitoring of Antiseizure Medications (ASMs) in Pediatric Patients
Simeoli et al.
The finding, in our words
This study found that volumetric absorptive microsampling shows satisfactory agreement with venous plasma for monitoring several antiseizure medications in paediatric patients. However, a blood-to-plasma conversion factor was required to estimate plasma concentrations for clobazam and carbamazepine metabolites due to poor capillary-to-plasma interchangeability.
A paraphrase to the Library’s standard, never the abstract. The source is one link away and is always the authority.
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 ↗
In children with SLE, VAMS finger-prick capillary blood gave haematocrit-adjusted MPA and MPAG concentrations indistinguishable from plasma, and the AUC from VAMS derived plasma-equivalent concentrations matched plasma AUC with R2 0.97. This supports accurate pharmacokinetically guided dosing of MMF using only three timed capillary microsamples.
Zhao et al., The journal of applied laboratory medicine (paywalled) · source ↗
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.
The study validated a VAMS-based LC-MS/MS method for measuring sirolimus levels, showing it was clinically equivalent to the standard whole blood method and suitable for therapeutic drug monitoring in paediatric transplant patients, supporting the use of decentralised microsampling for this purpose.
Kocur et al., Pharmacological reports : PR · source ↗
A study of 50 paediatric renal transplant recipients found that a validated VAMS LC-MS/MS method for tacrolimus showed high correlation with the reference method over 0.5–60 ng/mL, with minimal haematocrit effect.