Therapeutic drug monitoring in developing nations: assessing the current state of affairs in South America

Drug analysis: Comparison between dried plasma spots and liquid plasma samples of trauma patients from Cameroon—A feasibility study

“…The following substances were used as internal standards: 2 H 5alprazolam, 13 C 6 -amphetamine, 13 C 6 -benzoylecgonine, 2 H 4 -buprenorphine, 13 C 6 -clonazepam, 13 C 6 -cocaine, 13 C 2 -codeine, 13 C 6 -diazepam, 2 H 4 -diclazepam, 2 H 5 -fentanyl, 2 H 7 -flunitrazepam, 13 C 6 -MDMA, 13 C 6methadone, 13 C 6 -methamphetamine, 2 H 3 -morphine, 13 C 6 -nitrazepam, 13 C 6 -oxazepam, 2 H 3 -oxycodone, 13 C 4 -tetrahydrocannabinol, 13 C-2 H 3tramadol, 2 H 6 -zolpidem and 2 H 8 -zopiclone.…”

“…9 Dried blood or plasma spots have been used in epidemiological studies in LMICs, for example, in studies of infectious diseases 6,10,11 and in therapeutic drug monitoring. 12,13 Dried samples are also suitable for analysis of drugs of abuse. 7,14,15 Several devices are available to collect and ship dried matrix spots; some of them are designed to collect defined sample volumes.…”

“…Dried blood or plasma spots have been used in epidemiological studies in LMICs, for example, in studies of infectious diseases 6,10,11 and in therapeutic drug monitoring 12,13 . Dried samples are also suitable for analysis of drugs of abuse 7,14,15 …”

A strategy for low-cost portable monitoring of plasma drug concentrations using a sustainable boron-doped-diamond chip

“…Because this outsourcing takes a long turnaround time of several days to a few weeks and is costly, it is difficult to modify a therapeutic protocol for each patient in real time with reference to actual drug concentrations in plasma. Such disadvantages are hurdles for disseminating ‘therapeutic drug monitoring’ (TDM) as a standard of medical care to resource-limited areas, including local communities with small population and developing countries [ 3 , 4 ]. Notably, TDM is economically impactful; the global market size was valued at US$2.2 billion in 2021 and is expected to reach US$3.5 billion by 2028 ( https://precisionbusinessinsights.com/market-reports/global-therapeutic-drug-monitoring-market/ ).…”

A simple strategy for low-cost portable monitoring of plasma drug concentrations using a sustainable boron-doped-diamond chip

“…Such disadvantages are hurdles for disseminating 'therapeutic drug monitoring' (TDM) as a standard of medical care to resource-limited areas including local communities with small population and developing countries. 3,4 To address these bottlenecks, recently, a variety of biosensors suitable for portable or on-site drug monitoring were created; nevertheless, they have not yet been actually translated to routine clinical applications owing to the following problems. First, it is essential for the devices to be tested for sensor-to-sensor variability, and it is necessary to quantitively compare the measurements in realworld samples from patients to the results of current gold standard methods, but there are few studies where both evaluations have been performed.…”