Development and application of a LC-HRMS/MS method for analyzing antihypertensive drugs in oral fluid for monitoring drug adherence

Clinical Value of Emerging Bioanalytical Methods for Drug Measurements: A Scoping Review of Their Applicability for Medication Adherence and Therapeutic Drug Monitoring

“…Another recent study by Ghareeb [ 106 ] revealed that reducing blood contamination in the saliva by rinsing the oral cavity with water before sampling could improve the correlation coefficient between tacrolimus concentrations in oral fluid and whole blood. Another problem has been observed in some antiretroviral and antihypertensive drugs that are detected in very low concentrations in saliva [ 107 , 108 ]. For example, tenofovir is poorly diffused in saliva because it is almost completely ionized under physiological conditions and the ionized form has difficulty passing through the salivary glands [ 107 ].…”

Hyphenated mass spectrometry techniques for assessing medication adherence: advantages, challenges, clinical applications and future perspectives

“…Due to the high sensitivity and specificity, LC-MS/MS has been the main instrument of choice for the quantitative determination of therapeutic drugs in biosamples for this healthcare application. However, the monopoly of the tandem (MS/ MS) system is now being challenged by hyphenated HRMS systems with several studies using this approach to determine drug concentrations in biosamples to assess adherence to prescribed drug therapy [11,19,33,34,44,47,49,52,53,56,62,79].…”

“…It is only through the increased sophistication and detection capabilities of MS instruments that the microvolume DBS and VAMS sample can provide comparable data to a 1 mL blood sample. This enhanced analytical capability has also spurned the investigation of alternate less invasive biosample matrices including hair and saliva for assessing medication adherence [10,11,58,63,65,66,68,70,73,78,84,86,118,[129][130][131]. The choice of the most appropriate biosample would depend on a number of factors including the ease of sample collection from the patient and knowing if the available biosample size contains sufficient target analyte to be detected.…”

“…Historically, saliva has been less used in medication adherence studies, due to various limitations, but the reemergence of this minimally-invasive sampling matrix is probably due to the increased MS instrumental detection capabilities coupled with the potential in saliva to directly measure the therapeutically active free non-protein bound drug and the ease of sampling collection [135,136]. This sampling matrix was recently investigated to assess adherence to antihypertensive drugs where saliva produced comparable results to plasma except for acidic drug compounds [11].…”

“…Directly assessing drug, metabolite or biomarker levels in blood and urine samples provides an objective measure but levels may vary due to differences in patient metabolism and pharmacogenetics. Due to the ease of collection and non-invasiveness among other advantages, hair and saliva biosamples have been explored in medication adherence studies [10,11]. For therapeutic drugs there are well-documented pharmacokinetic relationships between the drug dose given and concentration of the drug in the blood stream.…”