Development and application of a multimatrix LC-MS/MS method for quantifying elexacaftor-tezacaftor-ivacaftor: Expanding therapeutic drug monitoring in cystic fibrosis from systemic circulation to airways and sweat

This study validated a method for monitoring mycophenolic acid in paediatric patients, demonstrating that quantitative dried plasma spots achieved close agreement with venous plasma. Quantitative dried blood spots showed significant haematocrit-related bias, making the plasma-based format more suitable for decentralised monitoring.

Matrix fidelity in microsampling: Plasma-first LC-MS/MS quantification of mycophenolic acid and MPAG — Kocur et al., Journal of chromatography. B, Analytical technologies in the biomedical and life sciences (paywalled) · source ↗

• venous-agreement
• blood
• qdbs
• tdm
• haematocrit
• dried
• pediatric
• immunosuppressants
• 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

The dried blood spot method via fingerprick showed greater variability than venipuncture for antipsychotic drug concentrations but was feasible in children and adolescents with behavioural problems, and higher risperidone trough concentrations correlated with both increased weight gain and greater effectiveness, enabling definition of a therapeutic window for safer dosing in this population.

[Improving the safety of antipsychotic drugs in children and adolescents by antipsychotic drug concentration measurements using a fingerprick] — Kloosterboer et al., Tijdschrift voor psychiatrie (paywalled) · source ↗

• blood
• dried
• capillary
• dbs
• validation
• venous-agreement
• pediatric
• tdm

A systematic review of dried blood spot sampling for tacrolimus monitoring across adult and paediatric organ transplant recipients demonstrated that reported analytical bias compared with venous sampling fell within acceptable limits across the majority of studies. This supports dried blood microsampling as an accurate approach for decentralised therapeutic drug monitoring.

Predictability of Capillary Blood Spot Toward Venous Whole Blood Sampling for Therapeutic Drug Monitoring of Tacrolimus in Solid Organ Transplant Recipients — Gallant et al., European journal of drug metabolism and pharmacokinetics (paywalled) · source ↗

• blood
• dried
• capillary
• dbs
• validation
• venous-agreement
• pediatric
• tdm
• immunosuppressants

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