2018 · European journal of clinical pharmacology · open access
Clinical validation study of dried blood spot for determining everolimus concentration in patients with cancer
Willemsen et al.
The finding, in our words
Dried blood spot sampling showed good agreement with whole blood for measuring everolimus in cancer patients, with ninety percent of samples demonstrating acceptable prediction error and low bias. This enables home-based therapeutic drug monitoring, allowing clinicians to individualise dosing without requiring patient visits.
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 ↗
Home DBS sampling gave testosterone results that agreed well with venous blood in men on intramuscular testosterone undecanoate, but showed falsely high values in those using topical gel, likely from skin contamination. Patients preferred home collection for its convenience, suggesting DBS is viable for decentralised monitoring of injectable testosterone if patients are taught proper technique.
Olthof et al., Clinical chemistry and laboratory medicine (paywalled) · source ↗
A review of 39 studies found that dried blood spot and volumetric absorptive microsampling show promising results for therapeutic drug monitoring of oral targeted anticancer drugs. The authors state that external validation remains crucial to confirm reliability, citing haematocrit effects and sample stability as key challenges.
Meertens et al., Biomedical Chromatography · 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 ↗
Capillary dried blood spot concentrations of levetiracetam agreed closely with plasma, with 92.1% within 20% of the mean and no proportional bias, and capillary matched venous dried blood spot with acceptable deviations; samples remained stable during postal transit, enabling at‑home self‑sampling for therapeutic drug monitoring.
Linder et al., Clinical biochemistry (paywalled) · source ↗