2014 · The Journal of clinical endocrinology and metabolism · paywalled
Pharmacokinetic-pharmacodynamic study of subcutaneous injection of depot nandrolone decanoate using dried blood spots sampling coupled with ultrapressure liquid chromatography tandem mass spectrometry assays
Singh et al.
The finding, in our words
Finger‑prick dried blood spots gave almost identical nandrolone and testosterone concentrations to venous samples. Home self‑collection for 21 days was well tolerated, showing that microsampling supports decentralised therapeutic drug monitoring without clinic visits, venesection or frozen storage.
A paraphrase to the Library’s standard, never the abstract. The source is one link away and is always the authority.
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.
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.
The study found that quantitative dried blood spot sampling provided high clinical agreement for tacrolimus and creatinine monitoring, with patients rating the self-collection devices as user-friendly. These results support the feasibility of decentralised therapeutic drug monitoring for immunosuppressants.
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.
This study found that dried blood spot samples stored at room temperature for four years correlated highly with serum measurements for testosterone and androstenedione, indicating that hematocrit adjustment may be unnecessary for serial monitoring in home-based self-sampling.