Simultaneous LC-MS/MS method for the quantitation of Azithromycin, Hydroxychloroquine and its metabolites in SARS-CoV-2(-/ +) populations using dried blood spots
Chhonker et al.
The finding, in our words
The authors validated a simultaneous LC-MS/MS assay for hydroxychloroquine, its metabolites, and azithromycin from self-collected dried blood spots. Requiring only ten microlitres of blood and achieving a sensitivity of one nanogram per millilitre, the method enabled remote therapeutic drug monitoring in more than two thousand specimens during the COVID-19 pandemic.
A paraphrase to the Library’s standard, never the abstract. The source is one link away and is always the authority.
A systematic review found mixed economic evidence for microsampling in therapeutic drug monitoring; one study reported no cost reduction with DBS home-sampling, €688 versus €676, whilst another predicted savings up to 61%. The authors caution that more work is required to assess costs alongside clinical outcomes and optimise logistics for decentralised implementation.
A quantitative dried blood spot method using only 10 µL of blood successfully quantified six azole antimycotics and showed samples were stable under conditions simulating postal mailing. A formula to convert dried spot results to plasma values was derived, though the authors note this is an in vitro validation and clinical studies are required for translation to patient care.
The study found that dried blood spot sampling showed good agreement with plasma concentrations for vancomycin and creatinine, with most differences within 20%, and patients preferred the finger prick method over venepuncture, supporting its use for decentralised therapeutic drug monitoring.
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.
This review found that volumetric microsampling devices, such as Mitra, HemaPEN, HemaXis DB10, and Tasso-M20, overcome haematocrit bias, whilst Telimmune plasma separation cards enable direct plasma collection without centrifugation. These technologies support patient-centric, decentralised sampling, though the authors note that clinical validation remains limited across different drugs and patient populations.