Therapeutic drug monitoring by dried blood spot: progress to date and future directions

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.

Clinical Validation of Venetoclax Volumetric Microsampling in Leukemia, with Whole-Blood-to-Plasma Conversion and Self-Microsampling Feasibility — Levens et al., Clinical Pharmacokinetics (paywalled) · source ↗

• vams
• venous-agreement
• blood
• dbs
• tdm
• self-collection
• haematocrit
• dried
• oncology
• capillary
• validation

VAMS microsampling found no significant difference from venous blood for tacrolimus in paediatric patients; samples were stable for 14 days, with average difference between paired at-home samples of 0.12 ± 0.94 ng/mL.

VAMS and parallel-reaction-monitoring mass spectrometry for tacrolimus trough measurements at home in paediatric heart-transplant patients — Zhao et al., J. Mass Spectrometry and Advances in the Clinical Lab · source ↗

• vams
• venous-agreement
• acceptability
• blood
• dbs
• tdm
• self-collection
• dried
• capillary
• pediatric
• immunosuppressants
• validation

A review of dried blood microsampling for tyrosine kinase inhibitor monitoring, covering the analytical and clinical requirements for moving oral cancer-drug TDM out of hospital.

Therapeutic Drug Monitoring of Tyrosine Kinase Inhibitors Using Dried Blood Microsamples — Verougstraete et al., Frontiers in Oncology · source ↗

• blood
• dbs
• tdm
• self-collection
• haematocrit
• dried
• oncology
• pediatric
• validation

Clinical validation for tacrolimus and mycophenolic acid monitoring showed that while volumetric absorptive microsampling met analytical criteria after concentration correction, conventional dried blood spots achieved superior adherence to strict clinical criteria, sample quality, and cost efficiency without significant haematocrit bias.

Comparison of conventional dried blood spots and volumetric absorptive microsampling for tacrolimus and mycophenolic acid determination — Paniagua-González et al., Journal of pharmaceutical and biomedical analysis (paywalled) · source ↗

• blood
• dried
• capillary
• vams
• dbs
• neoteryx-mitra
• self-collection
• validation
• venous-agreement
• tdm
• immunosuppressants
• economics
• haematocrit

Guardian-collected capillary dried blood spots were feasible for home monitoring of lamotrigine, and for carbamazepine and valproic acid when conversion factors were applied, with only 4 of 190 comparisons risking a conflicting dose decision and negligible risk of patient harm. Levetiracetam DBS showed high variability against plasma and is recommended only for checking nonadherence, not for dose adjustment.

Dried Blood Spot Self-Sampling by Guardians of Children With Epilepsy Is Feasible: Comparison With Plasma for Multiple Antiepileptic Drugs — Linder et al., Therapeutic drug monitoring (paywalled) · source ↗

• blood
• liquid
• dried
• capillary
• dbs
• self-collection
• validation
• venous-agreement
• pediatric
• tdm