Simultaneous determination of antiretroviral drugs in human hair with liquid chromatography-electrospray ionization-tandem mass spectrometry

New insights into chlorantraniliprole metabolic resistance mechanisms mediated by the striped rice borer cytochrome P450 monooxygenases: A case study of metabolic differences

The anthranilic diamide insecticide chlorantraniliprole has been extensively applied to control Lepidoptera pests. However, its overuse leads to the development of resistance and accumulation of residue in the environment. Four P450s (CYP6CV5, CYP9A68, CYP321F3, and CYP324A12) were first found to be constitutively overexpressed in an SSB CAP-resistant strain. It is imperative to further elucidate the molecular mechanisms underlying P450s-mediated CAP resistance for mitigating its environmental contamination. Here, we heterologously expressed these four P450s in insect cells and evaluated their abilities to metabolize CAP. Western blotting and reduced CO difference spectrum tests showed that these four P450 proteins had been successfully expressed in Sf9 cells, which are indicative of active functional enzymes. The recombinant proteins CYP6CV5, CYP9A68, CYP321F3, and CYP324A12 exhibited a preference for metabolizing the fluorescent P450 model probe substrates EC, BFC, EFC, and EC with enzyme activities of 0.54, 0.67, 0.57, and 0.46 pmol/min/pmol P450, respectively. In vitro metabolism revealed distinct CAP metabolic rates (0.97, 0.86, 0.75, and 0.55 pmol/min/pmol P450) and efficiencies (0.45, 0.37, 0.30, and 0.17) of the four recombinant P450 enzymes, thereby elucidating different protein catalytic activities. Furthermore, molecular model docking confirmed metabolic differences and efficiencies of these P450s and unveiled the hydroxylation reaction in generating N-demethylation and methylphenyl hydroxylation during CAP metabolism. Our findings not only first provide new insights into the mechanisms of P450s-mediated metabolic resistance to CAP at the protein level in SSB but also demonstrate significant differences in the capacities of multiple P450s for insecticide degradation and facilitate the evaluation and mitigation of toxic risks associated with CAP application in the environment.

Mass Spectrometry Analysis for Clinical Applications: A Review

Mass spectrometry (MS) has become an attractive analytical method in clinical analysis due to its comprehensive advantages of high sensitivity, high specificity and high throughput. Separation techniques coupled MS detection (e.g., LC-MS/MS) have shown unique advantages over immunoassay and have developed as golden criterion for many clinical applications. This review summarizes the characteristics and applications of MS, and emphasizes the high efficiency of MS in clinical research. In addition, this review also put forward further prospects for the future of mass spectrometry technology, including the introduction of miniature MS instruments, point-of-care detection and high-throughput analysis, to achieve better development of MS technology in various fields of clinical application. Moreover, as ambient ionization mass spectrometry (AIMS) requires little or no sample pretreatment and improves the flux of MS, this review also summarizes its potential applications in clinic.

Measurement Tools and Utility of Hair Analysis for Screening Adherence to Antihypertensive Medication

Poor adherence to the prescribed antihypertensive therapy is an understated public health problem and is one of the main causes of the high prevalence of uncontrolled hypertension in sub-Saharan Africa. Medication adherence is vital for the effectiveness of antihypertensive treatment and is key to ameliorating the clinical outcomes in hypertensive patients. However, it has often been ignored because the current methods used to assess medication adherence are not reliable, limiting their utilization in clinical practice. Therefore, the identification of the most accurate and clinically feasible method for measuring medication adherence is critical for tailoring effective strategies to improve medication adherence and consequently achieve blood pressure goals. This review not only explores various available methods for estimating medication adherence but also proposes therapeutic drug monitoring in hair for the measurement of medication adherence to the antihypertensive medication period.

Analytical approaches for determination of COVID-19 candidate drugs in human biological matrices

Since the outbreak of the COVID-19 pandemic, the use of antiviral and other available drugs has been considered to combat or reduce the clinical symptoms of patients. In this regard, it would be necessary to choose sensitive and selective analytical techniques for pharmacokinetic and pharmacodynamic studies, monitoring of drug concentration in biological fluids, and determination of the most appropriate dose to achieve the desired effect on the disease. In the present study, the analytical techniques based on spectroscopy and chromatography with different detectors for diagnosis and determination of candidate drugs in the treatment of COVID-19 in human biological fluids are reviewed during the period 2015-2022. Moreover, various sample preparation and extraction techniques, are being used for this purpose, such as protein precipitation (PP), solid-phase extraction (SPE), liquid-liquid extraction (LLE), and QuEChERS (quick, easy, cheap, effective, rugged, and safe) are investigated.

The Endocannabinoid System as a Potential Therapeutic Target for HIV-1-Associated Neurocognitive Disorder

Background: Despite the successful introduction of combined antiretroviral therapy, the prevalence of mild to moderate forms of HIV-associated neurocognitive disorders (HAND) remains high. It has been demonstrated that neuronal injury caused by HIV is excitotoxic and inflammatory, and it correlates with neurocognitive decline in HAND. Endocannabinoid system (ECS) protects the body from excitotoxicity and neuroinflammation on demand and presents a promising therapeutic target for treating HAND. Here, we firstly discuss the potential pathogenesis of HAND. We secondly discuss the structural and functional changes in the ECS that are currently known among HAND patients. We thirdly discuss current clinical and preclinical findings concerning the neuroprotective and anti-inflammatory properties of the ECS among HAND patients. Fourth, we will discuss the interactions between the ECS and neuroendocrine systems, including the hypothalamic-pituitary-adrenocortical (HPA) and hypothalamic-pituitary-gonadal (HPG) axes under the HAND conditions. Materials and Methods: We have carried out a review of the literature using PubMed to summarize the current state of knowledge on the association between ECS and HAND. Results: The ECS may be ideally suited for modulation of HAND pathophysiology. Direct activation of presynaptic cannabinoid receptor 1 or reduction of cannabinoid metabolism attenuates HAND excitotoxicity. Chronic neuroinflammation associated with HAND can be reduced by activating cannabinoid receptor 2 on immune cells. The sensitivity of the ECS to HIV may be enhanced by increased cannabinoid receptor expression in HAND. In addition, indirect regulation of the ECS through modulation of hormone-related receptors may be a potential strategy to influence the ECS and also alleviate the progression of HAND due to the reciprocal inhibition of the ECS by the HPA and HPG axes. Conclusions: Taken together, targeting the ECS may be a promising strategy to alleviate the inflammation and neurodegeneration caused by HIV-1 infection. Further studies are required to clarify the role of endocannabinoid signaling in HIV neurotoxicity. Strategies promoting endocannabinoid signaling may slow down cognitive decline of HAND are proposed.

A Resilience-Based Intervention to Mitigate the Effect of HIV-Related Stigma: Protocol for a Stepped Wedge Cluster Randomized Trial

Background

Despite decades of global efforts to tackle HIV-related stigma, previous interventions designed to reduce stigma have had limited effects that were typically in the small- to-moderate range. The knowledge gaps and challenges for combating HIV-related stigma are rooted both in the complexity of the stigma and in the limitations of current conceptualizations of stigma reduction efforts. Recent research has shown the promise of resilience-based approaches that focus on the development of strengths, competencies, resources, and capacities of people living with HIV (PLWH) and their key supporting systems (e.g., family members and healthcare providers) to prevent, reduce, and mitigate the negative effects of stigma. However, the resilience-based approach, while hypothesized, has rarely been empirically tested in large intervention trials, especially in resource-limited settings.

Methods

In this study, we propose to develop, implement, and evaluate a theory-guided, multilevel, multimodal resilience-based intervention via a stepped wedge cluster randomized trial among 800 PLWH and their biological or surrogate family members, as well as 320 healthcare providers in Guangxi, China with a longitudinal follow-up period of 36 months at 6-month intervals. The primary outcome will be viral suppression and the intermediate outcomes will include perceived stress and medication adherence of PLWH as well as resilience measures at the level of the individual, the family, and the healthcare system.

Discussion

The proposed study will be one of the first large scale efforts to examine whether resilience among PLWH can be fostered and sustained through a multilevel and multi-component HIV-related stigma intervention and whether a resilience-based intervention can improve clinical outcomes and quality of HIV care among PLWH in a low-resource setting. If efficacious, the intervention components could be tailored to other groups of PLWH and adapted for other low- and middle-income countries.

Trial Registration

This trial is registered at ClinicalTrials.gov, registration number NCT05174936, registered 13 December 2021. https://register.clinicaltrials.gov/prs/app/action/LoginUser?ts=3&cx=-jg9qo2.

Hair Zidovudine Concentrations Predict Virologic Outcomes Among People Living with HIV/AIDS in China

BACKGROUND

Hair antiretroviral concentrations are an objective and non-invasive measure of adherence to long-term antiretroviral therapy (ART) and can further predict virologic outcomes among people living with HIV/AIDS (PLWH). Zidovudine, one of the mainstream antiretrovirals in China, has been verified to have high reliability in adherence assessment, especially for its hair concentrations. However, data are limited in its predicting virologic outcomes. Therefore, this study aimed to characterize whether hair zidovudine concentrations can predict virologic suppression among Chinese PLWH compared with hair lamivudine concentrations and two self-reported measures, the overall frequency of adherence behaviors and percentage adherence.

METHODS

This cross-sectional study randomly recruited 564 PLWH currently treated with zidovudine, lamivudine, and other ART agents (efavirenz, nevirapine, or lopinavir/ritonavir) in Guangxi, China. Hair antiretroviral concentrations were determined using the LC-ESI⁺-MS/MS method. Receiver operating characteristic (ROC) curves were used to estimate the optimal classification thresholds of hair concentrations of zidovudine and lamivudine, and the two self-reported measures. Based on those optimal classification thresholds, logistic regression was used to examine whether those four adherence measures can predict virologic suppression (HIV-1 RNA <200 copies/mL).

RESULTS

ROC curves demonstrated good classification performance for association with virologic suppression of zidovudine with the optimal threshold at 58 pg/mg and lamivudine at 255 pg/mg but no self-reported measures. PLWH with hair zidovudine concentrations >58 pg/mg had an adjusted odds ratio (aOR) of 43.191 (95% confidence interval (CI) = 10.171‒183.418, p < 0.001) for virologic suppression. Hair lamivudine concentrations were also associated with virologic suppression (aOR = 10.656, 95% CI = 3.670‒30.943, p < 0.001). However, two self-reported measures did not predict virologic suppression (aORs = 1.157 and 2.488, ps >0.149).

CONCLUSION

Hair zidovudine concentrations can be served as an alternative tool for clinically predicting virologic suppression among PLWH in China.

Simultaneous Determination of 6 Antiretroviral Drugs in Human Hair Using an LC-ESI+-MS/MS Method: Application to Adherence Assessment

BACKGROUND

The determination of antiretroviral drugs in hair is receiving considerable research interest to assess long-term adherence to antiretroviral therapy (ART). Currently in China, lamivudine, zidovudine, nevirapine, efavirenz, ritonavir, and lopinavir are combined as first-line and second-line free therapy regimens and are recommended for people living with HIV (PLWH). Simultaneous determination of the 6 antiretroviral drugs in human hair is important for accurately and widely assessing long-term adherence in Chinese PLWH receiving different ART regimens.

METHODS

Six drugs were extracted from 10-mg hair samples incubated in methanol for 16 hours at 37°C and then analyzed by liquid chromatography with tandem mass spectrometry using a mobile phase of 95% methanol, with an electrospray ionization source in multiple reaction monitoring and positive mode.

RESULTS

The LC-ESI+-MS/MS method exhibited a linear range (R2 > 0.99) within 6-5000, 10-5000, 6-50,000, 12-50,000, 8-5000, and 8-12,500 pg/mg for lamivudine, zidovudine, nevirapine, efavirenz, ritonavir, and lopinavir. For all 6 drugs, the limits of quantification ranged between 6 and 12 pg/mg. The intraday and interday coefficients of variation were within 15%, and the recoveries ranged from 91.1% to 113.7%. Furthermore, the other validation parameters (ie, selectivity, matrix effect, stability, and carryover) met the acceptance criteria stipulated by guidelines of the US Food and Drug Administration and European Medicines Agency. Significant intergroup differences were observed between high-adherence and low-adherence groups, with high intercorrelations in the hair content of the 6 drugs.

CONCLUSIONS

The developed method demonstrated good reliability, to comprehensively and accurately assess adherence in PLWH receiving different ART regimens.

Factors influencing hair lamivudine concentration among people living with HIV in Guangxi, China

BACKGROUND

Hair antiretroviral concentration has served as an innovative and objective measure of antiretroviral adherence. However, some factors (for example, pharmacokinetics and hair characteristics) may contribute to the variability of hair antiretroviral concentration that may threaten the validity and reliability of the hair measure as a biomarker of adherence. This study aimed to examine the potential factors that may influence the measure of hair antiretroviral concentration.

METHODS

Hair samples from a cohort of 372 people living with HIV (PLHIV) receiving lamivudine (300 mg/day) in Guangxi, China. Lamivudine concentration was analysed using liquid chromatography-tandem mass spectrometry. Multivariable linear regression was used to evaluate the associations of hair lamivudine concentration with age, sex, ethnicity, height, weight, body mass index, duration of HIV diagnosis, duration of current regimen, dosing schedule, concomitant antiretroviral medications, frequency of hair washing, hair care products use, hair cosmetic treatment and self-reported adherence.

RESULTS

Multivariable models revealed that frequency of hair washing (β=-0.221, P=0.001), dosing schedule (β=0.141, P=0.036) and self-reported adherence (β=0.160, P=0.002) were associated with hair lamivudine concentration.

CONCLUSIONS

We observed that, among those potential factors, hair lamivudine concentration was influenced by frequency of hair washing and dosing schedule. Therefore, frequency of hair washing and dosing schedule should be considered in future research using hair lamivudine concentration as a measure of lamivudine exposure and biomarker of adherence.

The Value of Assessing Self-Reported and Biological Indicators of Outcomes in Evaluating HIV Programs

PURPOSE OF REVIEW

In this manuscript, we present recent findings concerning concordance and discrepancy between biological measures and self-reports of these three outcomes of HIV programs: HIV status, adherence to antiretroviral medications (ARVs) and use of and adherence to pre-exposure prophylaxis medication (PrEP), and condom use/unprotected sex.

RECENT FINDINGS

Recent studies suggest that three successive rapid HIV tests (for those whose first test in positive) might be reasonably inexpensive and valid biological data to collect to combine with self-reports of HIV status, dried blood spots sufficiently affordable to combine with self-reports of adherence to ARVs and use of or adherence to PrEP, and that the discrepancy between self-reports of condom use and biomarkers of unprotected sex may be relatively small in high-income countries. Additional work on assessment of incorrect condom usage and breakage, standardized self-report measures of condom use, and more private data collection methodologies in low-income settings might reduce the recent observed discrepancies even further. Concordance between self-reports of HIV and biomarkers indicating HIV positive status has varied considerably, with much lower rates in low-income countries, where the stigma of HIV is still very high. Recommendation is for combining self-report data with the results of three successive rapid tests for those testing positive. For adherence, again agreement between self-reports and a variety of more objective and/or biological measures is only moderate. Dried blood spots (DBS) may be sufficiently inexpensive in low-resource settings that this may be the best biological method to combine with self-reports. In publications over the last 8 years, the discrepancy between self-reports of condom use and biomarkers for unprotected sex may be even lower than 20% after controlling for other features of the study, particularly in high-income countries. Our results suggest that more careful assessment of incorrect condom use and breakage as reasons other than intentional misreporting should be investigated more carefully and that more private data collection methods such as audio, computer-assisted self-interviewing (ACASI) might be employed more often in low-resource settings to reduce this discrepancy in those settings further. In addition, further analysis of the discrepancy between self-reports of condom use and biomarkers should be conducted of published studies using the correct calculation methods to be more certain of these findings.

Analytical Methods for Determination of Antiviral Drugs in Different Matrices: Recent Advances and Trends

Viruses are the main pathogenic substances that cause severe diseases in humans and other living things. They are among the most common microorganisms, and consequently, antiviral drugs have emerged to prevent and treat viral infections. Antiviral drugs are an essential drug group considering their prescription and consumption rates for different diseases and indications. Therefore, it is crucial to develop accurate and precise analytical methods to detect antiviral drugs in various matrices. Chromatographic techniques are used frequently for the quantification purpose since they allow simultaneous determination of antivirals. Electrochemical methods have also gained importance since the analysis can be performed quickly without the need for pretreatment. Spectrophotometric and spectrofluorimetric methods are used because they are simple, inexpensive, and less time-consuming methods. The purpose of this review is to present an overview of the analysis of currently used antiviral drugs from 2010 to 2021. Since studies on antiviral drugs are numerous, selected publications were reviewed in this article. The analysis of antiviral drugs was divided into three main groups: chromatographic, spectrometric, and electrochemical methods which were applied to different matrices, including pharmaceutical, biological, and environmental samples.

Association of Hair Concentrations of Antiretrovirals with Virologic Outcomes Among People Living with HIV in Guangxi, China

BACKGROUND

Hair concentrations of antiretrovirals are an innovative and non-invasive method for measuring cumulative antiretroviral exposure and assessing long-term antiretroviral adherence. This study aimed to examine hair concentrations of antiretrovirals in relation to virologic outcomes among PLHIV in Guangxi, China.

METHODS

Cross-sectional data of hair concentrations of antiretrovirals and HIV viral load were collected from 215 PLHIV in Guangxi, China. Multivariate logistic regression analyses were used to examine the association of hair concentrations of antiretrovirals with virologic outcomes.

RESULTS

Of the 215 participants, 215, 67, and 163 PLHIV are receiving lamivudine, zidovudine, and efavirenz, respectively. Multivariate analysis revealed that hair concentrations of lamivudine [odds ratio = 16.52, 95% CI 2.51-108.60, p = 0.004] and efavirenz [odds ratio = 14.26, 95% CI 1.18-172.01, p = 0.036], but not zidovudine [odds ratio = 1.77, 95% CI 0.06-56.14, p = 0.747], were the strongest independent predictor of virologic suppression when controlling for sociodemographic and other HIV-related characteristics.

CONCLUSION

Hair concentrations of lamivudine and efavirenz were the strongest independent predictor of virologic suppression among Chinese PLHIV. Hair analysis of antiretrovirals may provide a non-invasive, cost-effective tool that predicts virologic suppression among PLHIV in China.

LC-MS/MS Quantification of Nevirapine and Its Metabolites in Hair for Assessing Long-Term Adherence

The adherence assessment based on the combination of nevirapine (NVP) and its two metabolites (2-hydroxynevirapine and 3-hydroxynevirapine) would more comprehensively and accurately reflect long-term adherence than that of a single prototype. This study aimed to develop a specific, sensitive and selective method for simultaneous detection of the three compounds in hair and explore whether there was consistency among the three compounds in assessing long-term adherence. Furthermore, 75 HIV-positive patients who were taking the NVP drug were randomly recruited and divided into two groups (high-and low-adherence group). All participants self-reported their days of oral drug administration per month and provided their hair strands closest to the scalp at the region of posterior vertex. The concentrations of three compounds in the hair were determined using a developed LC-MS/MS method in multiple reaction monitoring. This method showed good performances in limit of quantification and accuracy with the recoveries from 85 to 115% and in precision with the intra-day and inter-day coefficients of variation within 15% for the three compounds. The population analysis revealed that patients with high-adherence showed significantly higher concentrations than those with low-adherence for all three compounds. There were significantly moderate correlations of nevirapine with 2-hydroxynevirapine and 3-hydroxynevirapin and high correlation between 2-hydroxynevirapine and 3-hydroxynevirapin. The two NVP’s metabolites showed high consistency with NVP in evaluating long-term adherence.

Detection and quantification of Covid-19 antiviral drugs in biological fluids and tissues

Since coronavirus disease 2019 (COVID-19) started as a fast-spreading pandemic, causing a huge number of deaths worldwide, several therapeutic options have been tested to counteract or reduce the clinical symptoms of patients infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Currently, no specific drugs for COVID-19 are available, but many antiviral agents have been authorised by several national agencies. Most of them are under investigation in both preclinical and clinical trials; however, pharmacokinetic and metabolism studies are needed to identify the most suitable dose to achieve the desired effect on SARS-CoV-2. Therefore, the efforts of the scientific community have focused on the screening of therapies able to counteract the most severe effects of the infection, as well as on the search of sensitive and selective analytical methods for drug detection in biological matrices, both fluids and tissues. In the last decade, many analytical methods have been proposed for the detection and quantification of antiviral compounds currently being tested for COVID-19 treatment. In this review, a critical discussion on the overall analytical procedure is provided, i.e (a) sample pre-treatment and extraction methods such as protein precipitation (PP), solid-phase extraction (SPE), liquid–liquid extraction (LLE), ultrasound-assisted extraction (UAE) and QuEChERS (quick, easy, cheap, effective, rugged and safe), (b) detection and quantification methods such as potentiometry, spectrofluorimetry and mass spectrometry (MS) as well as (c) methods including a preliminary separation step, such as high performance liquid chromatography (HPLC) and capillary electrophoresis (CE) coupled to UV–Vis or MS detection. Further current trends, advantages and disadvantages and prospects of these methods have been discussed, to help the analytical advances in reducing the harm caused by the SARS-CoV-2 virus.

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Fourteen antiviral drugs were tested to counteract the effects of COVID-19.

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A review of analytical methods for antivirals detection is presented.

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Method validation, drugs extraction, separation and detection are discussed.

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LC-MS and MS/MS is mostly used for accurate and sensitive drugs quantification.

Application of High-Performance Liquid Chromatography for Simultaneous Determination of Tenofovir and Creatinine in Human Urine and Plasma Samples

Tenofovir disoproxil fumarate is widely used in the therapy of human immunodeficiency virus and hepatitis B virus; however, a high concentration of the prodrug effects kidney function damage. To control the effectiveness of kidney functions in treated patients, the level of creatinine in the body must be controlled. This work describes a simple, fast, and “plastic-waste” reducing method for the simultaneous determination of tenofovir and creatinine in human urine and plasma. In both assays, only 50 µL of body fluid was required. The tests were carried out by reversed phase high-performance liquid chromatography with UV detection. In urine samples, the limits of detection for tenofovir and creatinine were 4 µg mL⁻¹ and 0.03 µmol mL⁻¹, respectively. In plasma samples, the limits of detection were 0.15 µg mL⁻¹ for tenofovir and 0.0003 µmol mL⁻¹ for creatinine. The method was applied for the determination of tenofovir and creatinine in human urine and plasma samples. The biggest advantage of the elaborated method is the possibility to determine tenofovir and creatinine in one analytical run in both urine and plasma sample collected from HIV and HBV patients. The possibility to reduce the level of laboratory waste in a sample preparation protocol is in the mainstream of a new trend of analytical chemistry which is based on green chemistry.

Tandem mass spectrometry of small-molecule antiviral drugs: 1. HIV-related antivirals

Antiviral drugs are a class of compounds developed specifically for the treatment of viral infections. In the development and subsequent application of antiviral drugs, like for any other class of drugs, quantitative analysis in biological matrix is important, e.g., to establish bioavailability, to study pharmacokinetics, and later on possibly for therapeutic drug monitoring. Liquid chromatography-mass spectrometry (LC-MS) with tandem mass spectrometry (MS-MS) operated in selected-reaction monitoring (SRM) mode is the method of choice in quantitative bioanalysis. As information of the fragmentation of antiviral drugs in MS-MS is very much scattered in the scientific literature, it was decided to collect this information and to review it, not only to understand which product ions are actually used in SRM, but also to assist in other studies, e.g., in the identification of drug metabolites or (forced) degradation products. In this first study, attention is paid to antiviral agents used against HIV infection. The review provides fragmentation schemes of ca. 40 antiviral agents as well as several phosphorylated anabolites. The identity of the product ions used in SRM, i.e., elemental composition and exact-m/z, is tabulated, and more detailed fragmentation schemes are provided.

UPLC–MS/MS simultaneous determination of methamphetamine, amphetamine, morphine, monoacetylmorphine, ketamine, norketamine, MDMA, and MDA in hair

Hair is a stable specimen and has a longer detection window (from weeks to months) than blood and urine. Through the analysis of hair, the long-term information of the drug use of the identified person could be explored. Our work is to establish an ultra-performance liquid chromatography–tandem mass spectroscopy (UPLC–MS/MS) method for simultaneous determination of methamphetamine, amphetamine, morphine, monoacetylmorphine, ketamine, norketamine, 3,4-methylenedioxymethamphetamine (MDMA), and 3,4-methylenedioxyamphetamine (MDA) in hair. Methoxyphenamine was used as an internal standard. The chromatographic separation was performed on a UPLC ethylene bridged hybrid (BEH) C18 (2.1 mm × 50 mm, 1.7 μm) column using a mobile phase of acetonitrile–water with 10 mmol/L ammonium acetate solution which containing 0.05% ammonium hydroxide. The multiple reaction monitoring in positive electrospray ionization was used for quantitative determination. The intra-day and inter-day precisions (relative standard deviation [RSD]) were below 15%. The accuracy ranged between 85.5% and 110.4%, the average recovery rate was above 72.9%, and the matrix effect ranged between 92.7% and 109.2%. Standard curves were in the range of 0.05–5.0 ng/mg, and the correlation coefficients were greater than 0.995. The established UPLC–MS/MS method was applied to analyze the hair samples successfully.

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

Nonadherence to prescribed pharmacotherapy is an understated public health problem globally and is costing many patients their chance to return to good health and healthcare systems billions. Clinicians need an accurate assessment of adherence to medications to aid the clinical decision-making process in the event of poor patient progress and to maximise the patient health outcomes from the drug therapies prescribed. An overview of indirect and direct methods used to measure medication adherence is presented, highlighting the potential for accurate measuring of drugs in biological samples using hyphenated mass spectrometry (MS) techniques to provide healthcare professionals with a reliable evidence base for clinical decision making. In this review we summarise published applications of hyphenated MS techniques for a diverse range of clinical areas demonstrating the rise in the use of such direct methods for assessing medication adherence. Although liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods using plasma, serum and urine samples are the most popular, in recent years increased attention has been given to liquid chromatography high-resolution mass spectrometry (LC-HRMS) methods and alternative biosample matrices including hair, saliva and blood microsamples. The advantages and challenges of using hyphenated MS techniques to address this healthcare problem are also discussed alongside future perspectives.

Comparing self-reported medication adherence measures with hair antiretroviral concentration among people living with HIV in Guangxi, China

BACKGROUND

Antiretroviral adherence is essential to HIV treatment efficacy. Various self-reported measures are commonly used for assessing antiretroviral adherence. Limited data are available regarding the validity of those self-reported measures in comparison with long-term objective biomarkers of adherence measures such as hair measures.

METHODS

Self-reported adherence (frequency, percentage, and visual analog scale [VAS]) and hair tenofovir concentration were evaluated at a single time point from 268 people living with HIV in China. The responses to each of three self-reported measures were converted into percentage and then dichotomized as "optimal" (100%) vs. "suboptimal" (less than 100%) adherence. Two composite adherence scores (CAS) were created from the three self-reported measures: (1) an overall adherence was the average percentage of the three self-reported measures; (2) responses were termed optimal adherence if participants reporting optimal adherence in all three self-reported measures, while were termed suboptimal adherence. Hair tenofovir concentration was also dichotomized as "optimal" (above the limit of quantitation, 36 pg/mg) vs. "suboptimal" adherence (blow 36 pg/mg). Spearman correlation, kappa statistics, and logistic regression analysis were used to calculate the correlations, agreements, and predictions of self-reported measures with hair measure, respectively.

RESULTS

Overall adherence, but any of the three self-reported adherence, was correlated with hair tenofovir concentration (r = 0.13, p < 0.05). Self-reported optimal adherence in VAS and CAS measures were agreed with and predicted optimal adherence assessed by hair measure (Kappa = 0.107, adjusted OR = 1.88, 95% CI 1.03-3.45; Kappa = 0.109, adjusted OR = 1.80, 95% CI 1.02-3.18; all p < 0.05, respectively).

CONCLUSION

VAS may be a good individual self-reported measure for antiretroviral adherence, and CAS may be a good composite self-reported measure for antiretroviral adherence.

Preclinical Pharmacokinetics of Lamivudine and Its Interaction with Schisandra chinensis Extract in Rats

Schisandra chinensis (Turcz.) Baill. (S. chinensis) extract and its active ingredient, schizandrin, have been used as a botanical medicine and dietary supplement for the treatment of hepatitis. Lamivudine is an antiretroviral drug and is used to treat hepatitis B viral infection. The aim of this study was to develop an ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for the measurement of lamivudine and to determine the pharmacokinetic behaviors of an aqueous-ethanol extract of S. chinensis in rats. The separation was performed on a phenyl column maintained at 40 °C. The experimental animals were distributed into three groups: (1) lamivudine alone (10 mg/kg, i.v.); (2) lamivudine (10 mg/kg, i.v.) + pretreatment with S. chinensis (3 g/kg, p.o.); and (3) lamivudine (10 mg/kg, i.v.) + pretreatment with S. chinensis (10 g/kg, p.o.). The experimental results indicated that neither treatment with lamivudine alone nor pretreatment with S. chinensis (3 or 10 g/kg) significantly changed the pharmacokinetic parameters. In conclusion, based on the above preclinical experimental model, the combination of lamivudine with the herbal extract of S. chinensis did not exhibit significant pharmacokinetic interactions. These data offer useful information for assessing the preclinical safety of nutritional supplementation with lamivudine.

Antiretroviral Concentration in Hair as a Measure for Antiretroviral Medication Adherence: A Systematic Review of Global Literature

This review aims to validate hair antiretroviral concentration (HAC) as a measure for antiretroviral medication adherence. This review included 31 studies that analyzed a total of 11 ARV drugs in four different drug classes. The associations between HAC and non-pharmacokinetic measures were generally lower than the association between HAC and other pharmacokinetic measures: the correlation coefficients (r) ranged from - 0.20 to 0.38 for self-report or pill counts and 0.20 to 0.85 for electronic drug monitoring; HAC and other pharmacokinetic measures were positively correlated with the correlation coefficients (r) ranging from 0.20 to 0.72, 0.34 to 0.86, 0.50 to 0.85 for antiretroviral concentration in plasma, peripheral blood mononuclear cells, and dried blood spots, respectively. HAC was one of the strongest independent predictors of virologic responses. HAC of tenofovir was significantly associated with renal toxicity in large sample studies. This review suggests that HAC is a valid biomarker of antiretroviral medication adherence.