Hair analysis to monitor adherence to prescribed chronic inhaler drug therapy in patients with asthma or COPD

Therapeutic drug monitoring of corticosteroids/β2-agonists in the hair of patients with asthma: an open-label feasibility study

Background: Although adherence to inhaled medication is critically important for treatment efficiency, around half of patients taking these drugs are non-adherent or make critical errors when using their delivery device. Segmental hair analysis might be a valuable tool for therapeutic monitoring because hair concentrations reflect exposure from month to month. The objective of the present proof-of-concept study was to establish the feasibility of segmental hair analysis of inhaled budesonide and formoterol in asthma patients. Methods: We conducted a prospective, open-label, interventional study of adult patients being treated with budesonide/formoterol for controlled, moderate-to-severe asthma (CorticHair, NCT03691961). Asthma control, lung function, and medication adherence were recorded. Hair samples were taken 4 months after enrolment and cut into four 1 cm segments. Results: Samples were available from 21 patients (20 women; median age: 53; median budesonide dose: 600 μg/d). Budesonide and formoterol were detected in samples from 18 to 13 patients, respectively. The median hair concentrations were 6.25 pg/mg for budesonide and 0.9 pg/mg for formoterol. The intrapatient coefficient of variation between hair segments was 21% for budesonide and 40% for formoterol. Pearson's coefficients for the correlations between the hair concentration and the self-reported drug dose and the prescribed drug dose were respectively 0.42 (p = 0.08) and 0.29 (p = 0.25) for budesonide and 0.24 (p = 0.44) and 0.17 (p = 0.57) for formoterol. Conclusion: Segmental hair analysis of inhaled medications was feasible, with low intrapatient variability. This innovative, non-invasive means of assessing monthly drug exposure might help physicians to personalize drug regimens for patients with difficult-to-treat asthma.

Up-to-date guidance towards improving medication adherence in patients with chronic obstructive pulmonary disease

INTRODUCTION

Despite efficacious treatment for chronic obstructive pulmonary disease (COPD), medication adherence remains quite poor, with most estimates based on electronic monitoring devices ranging from 20-30%. This degree of nonadherence represents a significant missed opportunity to realize the benefits of treatment of this disease.

AREAS COVERED

In this article, we review research on the prevalence of nonadherence among patients with COPD, the association of nonadherence with health outcomes, barriers to adherence in this patient population, and potential interventions.

EXPERT OPINION

Integrating research into practice involves assessing patients' adherence, identifying modifiable barriers to adherence, open discussion of these barriers with patients, and tailored interventions to address them. These interventions may include treatment of previously unrecognized comorbid disease, providing educational or behavioral interventions, optimizing prescribing strategies, use of adherence aids, or addressing cost and other access barriers. Electronic inhaler monitors are promising interventions for both monitoring and improving adherence. However, remaining concerns about integration into patient care, data management, cost, acceptability, and ethical and privacy issues must be overcome prior to their implementation in clinical practice.

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.

Hair analysis as a new tool to monitor adherence to long-term therapy to statins

Statins are cholesterol-lowering medications which are widely prescribed as first-line treatment for hyperlipidemia, against high blood cholesterol aimed at reducing the risk of atherosclerotic diseases. Notwithstanding their undoubted efficacy, the needed long-term treatment with these drugs is characterized by a high percentage of dropout. Consequently, an effective tool to verify the patients' compliance to statin therapy is needed. In this context, the analysis for drugs and drug metabolites in the hair may represent an almost ideal tool because, according to a sound body of forensic toxicological literature, concentrations in the hair matrix reflect the chronic intake of drugs and pharmaceuticals. In this light, in the present study, a novel, specific and sensitive ultra-performance liquid chromatography-tandem mass spectrometry method has been developed to determine six statins and their metabolites (namely atorvastatin, (p)α-OH-atorvastatin-lactone, (o)α-OH-atorvastatin-lactone, rosuvastatin, N-desmethyl rosuvastatin and pravastatin) in human hair. After optimization, the method was successfully validated in terms of selectivity, linearity, sensitivity, precision, accuracy, stability and matrix effect. Moreover, the practical applicability of this method for verifying adherence to statin therapy was assessed by testing samples of hair collected from subjects under long-term therapy with statins.

Hair analysis for beta-blockers and calcium-channel blockers by using liquid chromatography-tandem mass spectrometry as a tool for monitoring adherence to antihypertensive therapy

Adherence to therapy is the key to a successful therapeutic intervention, especially in cardiovascular diseases in which a lack of adherence may have serious consequences in terms morbidity and/or mortality. In this context, hair analysis can be an excellent tool to monitor adherence to therapy. Indeed, drugs present in blood are incorporated into the hair matrix, where drugs and metabolites can stay unaltered for a long time protected from metabolism and degradation. In the present study, a simple, specific, and sensitive ultra-high performance liquid-chromatography-tandem mass spectrometry (UHPLC-MS/MS) method set up to determine in human hair seven beta-blockers (viz., metoprolol, sotalol, labetalol, atenolol, nebivolol, bisoprolol, and nadolol) and two calcium-channel blockers (lercanidipine and amlodipine), which are widely prescribed to treat medium-to-severe hypertensive conditions. The optimized method was successfully validated in terms of accuracy, repeatability, reproducibility, matrix effect and extraction recovery. Moreover, the applicability of the method was evaluated by analyzing 34 real samples of hair obtained from patients under long-term therapy with calcium channel blockers and beta-blockers.

Assessing adherence to inhaled therapies in asthma and the emergence of electronic monitoring devices

Infrequent use of inhaled corticosteroids (ICS) and/or over-reliance of short-acting β-agonists (SABA) are recognised as key contributors to increased morbidity and mortality in asthma. The most frequent measures of ICS adherence and SABA use rely on patient-reported questionnaires or prescription refill records, neither of which are considered sufficiently reliable. Technological advancements in the development of electronic monitoring of inhaler devices allow for monitoring of use, as well as recording of and feedback on inhaler technique for some devices. Most electronic monitoring devices (EMDs) are paired with a smartphone application, allowing patients to set reminders and display both preventer and reliever use over time. This allows identification of intentional and unintentional ICS non-adherence as well as frequency of SABA use. This information assists clinicians in distinguishing difficult-to-control from severe asthma. Although additional evidence is required to assess the impact of EMDs on clinical outcome measures such as exacerbation rate, the introduction of EMDs into the asthma armoury is a significant step forward in asthma care with the potential to improve asthma-related outcomes.

Adherence to Inhaled Corticosteroid Therapy and Its Clinical Impact on Asthma Control in Adults Living with Asthma in Northwestern Ethiopian Hospitals

BACKGROUND

Inhaled corticosteroids (ICS) are the backbone of and primary choice for long-term asthma control therapy; however, the level of adherence to this regimen has not yet been investigated, particularly in the study area of Northwest Ethiopia. Therefore, this study aimed to examine the level of adherence to ICS treatment and its impact on adults living with asthma in Northwestern Ethiopian hospitals.

MATERIALS AND METHODS

A multicenter institution-based survey was conducted in asthma patients treated with ICS-based regimens in public hospitals in Northwest Ethiopia. Adherence to ICS was measured with the Medication Adherence Report Scale for Asthma. Descriptive statistics were used to present respondents' characteristics, and logistic regression was used to test associations between predictors and outcome variables. A level of p<0.05 was used as a cut-off point for a significant association.

RESULTS

Of a total of 422 approached subjects, 96.7% completed the survey. The mean (±SD) age of the participants was 49.82 (±16.1) years. The majority of participants (86.1%) had a low level of adherence to ICS treatment. A significant proportion (42%) of the respondents reported that they utilized ICS only before performing exercises that made them breathless. Around two-fifths of the participants used ICS either when they needed it or when they felt breathless. Furthermore, one-third of the study subjects reported that they either avoided or forgot to take ICS. Participants who had access to free healthcare services had better adherence to ICS (p=0.01), and non-adherence to ICS therapy was significantly associated with poor levels of asthma control (p≤0.001).

CONCLUSION

This study found that adult patients with asthma had low levels of adherence to ICS therapy. Future prospective research in a larger population, focusing on identifying the obstacles to ICS adherence in patients living with asthma and creating successful intervention options, is recommended.

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

INTRODUCTION

Direct quantification of drug concentrations allows for medication adherence monitoring (MAM) and therapeutic drug monitoring (TDM). Multiple less invasive methods have been developed in recent years: dried blood spots (DBS), saliva, and hair analyses.

AIM

To provide an overview of emerging drug quantification methods for MAM and TDM, focusing on the clinical validation of methods in patients prescribed chronic drug therapies.

METHODS

A scoping review was performed using a systematic search in three electronic databases covering the period 2000-2020. Screening and inclusion were performed by two independent reviewers in Rayyan. Data from the articles were aggregated in a REDCap database. The main outcome was clinical validity of methods based on study sample size, means of cross-validation, and method description. Outcomes were reported by matrix, therapeutic area and application (MAM and/or TDM).

RESULTS

A total of 4590 studies were identified and 175 articles were finally included; 57 on DBS, 66 on saliva and 55 on hair analyses. Most reports were in the fields of neurological diseases (37%), infectious diseases (31%), and transplantation (14%). An overview of clinical validation was generated of all measured drugs. A total of 62 drugs assays were applied for MAM and 131 for TDM.

CONCLUSION

MAM and TDM are increasingly possible without traditional invasive blood sampling: the strengths and limitations of DBS, saliva, and hair differ, but all have potential for valid and more convenient drug monitoring. To strengthen the quality and comparability of future evidence, standardisation of the clinical validation of the methods is recommended.

Matrix-assisted laser desorption ionisation (MALDI) mass spectrometry (MS): basics and clinical applications

Background Matrix-assisted laser desorption ionisation (MALDI) mass spectrometry (MS) has been used for more than 30 years. Compared with other analytical techniques, it offers ease of use, high throughput, robustness, cost-effectiveness, rapid analysis and sensitivity. As advantages, current clinical techniques (e.g. immunoassays) are unable to directly measure the biomarker; rather, they measure secondary signals. MALDI-MS has been extensively researched for clinical applications, and it is set for a breakthrough as a routine tool for clinical diagnostics. Content This review reports on the principles of MALDI-MS and discusses current clinical applications and the future clinical prospects for MALDI-MS. Furthermore, the review assesses the limitations currently experienced in clinical assays, the advantages and the impact of MALDI-MS to transform clinical laboratories. Summary MALDI-MS is widely used in clinical microbiology for the screening of microbial isolates; however, there is scope to apply MALDI-MS in the diagnosis, prognosis, therapeutic drug monitoring and biopsy imaging in many diseases. Outlook There is considerable potential for MALDI-MS in clinic as a tool for screening, profiling and imaging because of its high sensitivity and specificity over alternative techniques.

Measuring adherence to therapy in airways disease

Non-adherence to medication is one of the most significant issues in all airways disease and can have a major impact on disease control as well as on unscheduled healthcare utilisation. It is vital that clinicians can accurately determine a patient's level of adherence in order to ensure they are gaining the maximal benefit from their therapy and also to avoid any potential for unnecessary increases in therapy. It is essential that measurements of adherence are interpreted alongside biomarkers of mechanistic pathways to identify if improvements in medication adherence can influence disease control. In this review, the most common methods of measuring adherence are discussed. These include patient self-report, prescription record checks, canister weighing, dose counting, monitoring drug levels and electronic monitoring. We describe the uses and benefits of each method as well as potential shortcomings. The practical use of adherence measures with measurable markers of disease control is also discussed.

Educational aims

To understand the various methods available to measure adherence in airways disease.To learn how to apply these adherence measures in conjunction with clinical biomarkers in routine clinical care.

Global burden of medication non-adherence in chronic obstructive pulmonary disease (COPD) and asthma: a narrative review of the clinical and economic case for smart inhalers

Medication non-adherence to asthma and chronic obstructive pulmonary disease therapy poses a significant burden for patients and societies. Non-adherence encompasses poor initiation, implementation (including poor inhalation technique) and non-persistence. Globally, non-adherence is associated with poor clinical outcomes, reduced quality of life and high healthcare and societal costs. Costs are mainly caused by excess hospitalizations and impaired work productivity. Multiple intervention programs to increase adherence in patients with asthma and chronic obstructive pulmonary disease have been conducted. However, these intervention programs are generally not as effective as intended. Additionally, adherence outcomes are mostly examined with non-objective or non-granular measures (e.g., self-report, dose count, pharmacy records). Recently developed smart inhalers could be the key to objectively diagnose and manage non-adherence effectively in patients with asthma and chronic obstructive pulmonary disease. Smart inhalers register usage of the inhaler, record time and date, send reminders, give feedback about adherence and some are able to assess inhaler technique and predict exacerbations. Still, some limitations need to be overcome before smart inhalers can be incorporated in usual care. For example, their cost-effectiveness and budget impact need to be examined. It is likely that smart inhalers are particularly cost-effective in specific asthma and chronic obstructive pulmonary disease subgroups, including patients with asthma eligible for additional GINA-5 therapy (oral corticosteroids or biologics), patients with severe asthma in GINA-5, patients with asthma with short-acting beta2 agonists overuse, patients with asthma and chronic obstructive pulmonary disease with frequent exacerbations and patients with asthma and chronic obstructive pulmonary disease of working-age. While there is high potential and evidence is accumulating, a final push seems needed to cost-effectively integrate smart inhalers in the daily management of patients with asthma and chronic obstructive pulmonary disease.

Exercise and Asthma

Asthma is a chronic lower respiratory disease that is very common worldwide, and its incidence is increasing year by year. Since the 1970s, asthma has become widespread, with approximately 300 million people affected worldwide and about 250,000 people have lost their lives. Asthma seriously affects people's physical and mental health, resulting in reduced learning efficiency, limited physical activities, and decreased quality of life. Therefore, raising awareness of the risk of asthma and how to effectively treat asthma have become important targets for the prevention and management of asthma in recent years. For patients with asthma, exercise training is a widely accepted adjunct to drug-based and non-pharmacological treatment. It has been recommended abroad that exercise prescriptions are an important part of asthma management.

Liquid chromatography-mass spectrometry method for the quantification of corticosteroids, β2-adrenoreceptor agonists and anticholinergics in human hair

Pharmacological treatments of asthma and chronic obstructive pulmonary disease include medications such as inhaled corticosteroids, long- or short-acting β₂-adrenoreceptor agonists and anticholinergics. There is an unmet need for the monitoring of adherence and drug exposure to those therapies since poor adherence and/or inhalation technique may impact the control of the disease and the pharmacological strategy. Since plasma therapeutic drug monitoring only reflects the body exposure in the last few hours, the measurement of hair drug concentrations may be of great interest to assess the chronic exposure. A liquid chromatography - tandem mass spectrometry method was therefore developed for the quantification of corticosteroids, β₂-adrenoreceptor agonists and anticholinergics in human hair. The method was validated according to the European Medicines Agency and Food and Drug Administration guidelines. Sensitivity, accuracy and precision were excellent, allowing the quantification of drugs in the pg/mg range. The method was shown suitable for the analysis of clinical hair samples, demonstrating that it could be used for hair therapeutic drug monitoring in asthma or chronic obstructive pulmonary disease patients.

Measuring and reporting treatment adherence: What can we learn by comparing two respiratory conditions?

Medication non-adherence, defined as any deviation from the regimen recommended by their healthcare provider, can increase morbidity, mortality and side effects, while reducing effectiveness. Through studying two respiratory conditions, asthma and tuberculosis (TB), we thoroughly review the current understanding of the measurement and reporting of medication adherence. In this paper, we identify major methodological issues in the standard ways that adherence has been conceptualised, defined and studied in asthma and TB. Between and within the two diseases there are substantial variations in adherence reporting, linked to differences in dosing intervals and treatment duration. Critically, the communicable nature of TB has resulted in dose-by-dose monitoring becoming a recommended treatment standard. Through the lens of these similarities and contrasts, we highlight contemporary shortcomings in the generalised conceptualisation of medication adherence. Furthermore, we outline elements in which knowledge could be directly transferred from one condition to the other, such as the application of large-scale cost-effective monitoring methods in TB to resource-poor settings in asthma. To develop a more robust evidence-based approach, we recommend the use of standard taxonomies detailed in the ABC taxonomy when measuring and discussing adherence. Regimen and intervention development and use should be based on sufficient evidence of the commonality and type of adherence behaviours displayed by patients with the relevant condition. A systematic approach to the measurement and reporting of adherence could improve the value and generalisability of research across all health conditions.

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.

Assessing Adherence to Inhaled Corticosteroids Among Adults with Asthma in Kuwait Using the Medication Adherence Report Scale for Asthma

PURPOSE

Inhaled corticosteroids (ICS) are the mainstay maintenance therapy for asthma management. Non-adherence to ICS, which can lead to exacerbations and poor asthma control, is commonly reported among adult patients with asthma. The level of adherence to ICS among adult patients with asthma in Kuwait has not been previously published. The aim of this study was to assess adherence to ICS among adults with asthma in Kuwait.

PATIENTS AND METHODS

A cross-sectional study was conducted among adult patients with asthma using ICS therapy at ambulatory asthma clinics in Kuwait. Adherence to ICS was assessed using the Medication Adherence Report Scale for Asthma (MARS-A). Descriptive and logistic regression analyses were conducted using SPSS version 23.

RESULTS

One hundred and forty-nine patients with a mean age of 41.42 (12.75) years participated in the study. The majority of the participants (82.6%) reported low adherence to ICS. Approximately, three-quarters of the participants reported that they used ICS either when needed or when they felt breathless. Furthermore, about half of them admitted that they tried to avoid using ICS (46.3%), or forgot to take ICS (51%), or only used ICS before performing an exercise that made them breathless (54%). In the multivariate logistic regression analysis, independent predictors (age, education, and smoking status) were not found to significantly influence the overall adherence to ICS therapy.

CONCLUSION

Adherence to ICS among adult patients with asthma was found to be low in ambulatory care settings in Kuwait. Future studies should aim to determine the barriers to ICS adherence among patients with asthma, with a focus on developing effective intervention strategies.

Trajectory Analyses of Adherence Patterns in a Real-Life Moderate to Severe Asthma Population

BACKGROUND

Global Initiative for Asthma step 5 therapies (GINA-5), other than inhaled corticosteroids and long-acting β-agonists in fixed dose combinations (ICS/LABA FDC), often entail more expensive (eg, monoclonal biologics) or less safe (eg, maintenance oral corticosteroids [OCS]) treatments. It is therefore important to assess poor inhaler adherence as a possible cause of suboptimal response to ICS/LABA FDC before additional GINA-5.

OBJECTIVE

To determine rates of, and time to, additional GINA-5 after first-year ICS/LABA FDC use, and their association with inhaler adherence.

METHODS

Patients initiating ICS/LABA FDC between 2013 and 2017 were identified from Australian national dispensing data. Group-based trajectory modeling was used to estimate medication adherence patterns. Multivariable Cox proportional hazards models were used to examine the association between adherence trajectories and GINA-5 addition during 2-year follow-up.

RESULTS

In total, 3062 new ICS/LABA FDC users were identified, of whom 120 (3.9%) received additional GINA-5 (OCS: 89; long-acting muscarinic antagonists: 39; biologics: <3). Mean time to commencing additional GINA-5 was 705.2 (standard deviation, 1.7) days. Adherence trajectories were nonpersistent use (20%), seasonal use (8%), poor adherence (58%), and good adherence (13%). Although poor adherence was associated with longer time to additional GINA-5 (adjusted hazard ratio: 0.58; 95% confidence interval: 0.35-0.95), over 80% of additional GINA-5 was commenced in poorly adherent patients. Use of ≥2 OCS/antibiotic courses also predicted additional GINA-5.

CONCLUSIONS

Almost 1 in 20 people with asthma commenced additional GINA-5 after ICS/LABA initiation, most of whom (>80%) were poorly adherent to inhaled preventers. There is a substantial unmet need for inhaler adherence to be addressed before prescribing additional GINA-5.

Prevalence and predictors of adherence to controller therapy in adult patients with severe/difficult-to-treat asthma: a systematic review and meta-analysis

Objective: Nonadherence to prescribed treatment is an important cause for poor asthma control. This systematic review aimed to determine the prevalence and determinants of nonadherence in adult patients with severe asthma.Data sources: Embase and Pubmed were searched for publications in English studying adult patients and containing the keywords "severe asthma", "adherence", and "compliance".Study selection: Only studies utilizing objective methods for monitoring adherence and clear definition of the level of asthma severity were included. Predominantly pediatric studies or studies of less severe asthma were excluded.Results: The search returned 488 reports, of which 14 reports (of 2297 patients) were included. The weighted mean age of patients was 44 years and 64% were females. In studies using a cutoff of acquiring 50% or less of the medication, an overall rate of nonadherence was 42.9%. For studies reporting nonadherence of a continuous scale, the weighted mean nonadherence was 42.9% (95% CI 28.2-49.5). Meta-analysis of adherence predictors showed that male sex was associated with adherence with an odds ratio of 2.25 and higher asthma quality of life questionnaire (AQLQ) scores with a mean difference 0.47 points in adherent patients. Other predictors were reported to have significant association with adherence (e.g. older age, more knowledge about asthma, simpler medication schedules) but these were from single studies.Conclusion: Nonadherence to therapy is a common problem in the management of patients with severe asthma. More robust and objective methods are needed to homogenize and improve the accuracy of assessment methods. More studies are needed from developing countries. Systematic review registration number: CRD42018114669.

Status of and strategies for improving adherence to COPD treatment

Despite the wide application of adherence as a concept, the definition, evaluation and improvement of the adherence to treatment by patients with chronic obstructive pulmonary disease (COPD) still present some challenges. First, it is necessary to clearly define the concepts of treatment adherence, compliance and persistence. Second, it is critical to consider the various methods of evaluating and quantifying adherence when interpreting adherence studies. In addition, the advantages and disadvantages of the different ways of measuring treatment adherence should be taken into account. Another subject of some debate is the number of variables associated with COPD treatment adherence. Adherence is a complex concept that goes beyond the dosage or the use of inhalation devices, and a number of variables are involved in determining adherence, from the clinical aspects of the disease to the patient's confidence in the doctor's expertise and the level of social support experienced by the patient. Notably, despite these challenges, the importance of adherence has been well established by clinical trials and routine clinical practice. The available evidence consistently shows the substantial impact that a lack of adherence has on the control of the disease and its long-term prognosis. For these reasons, the correct evaluation of therapeutic adherence should be a key objective in clinical interviews of patients. In recent years, various initiatives for improving adherence have been explored. All these initiatives have been based on patient education. Therefore, health care professionals should be aware of the issues pertaining to adherence and take the opportunity to educate patients each time they contact the health care system.

Quantification of the tyrosine kinase inhibitor erlotinib in human scalp hair by liquid chromatography-tandem mass spectrometry: Pitfalls for clinical application

An LC-MS/MS method was developed and validated to quantify the tyrosine kinase inhibitor erlotinib in human scalp hair, as alternative matrix to monitor long-term erlotinib exposure. Hair samples from 10 lung cancer patients were measured and correlated with plasma concentrations. Hair segments of 1 ± 0.1 cm each were pulverized and for at least 18 h incubated in methanol at ambient temperature. A liquid-liquid extraction purified the extracts and they were analyzed with LC-MS/MS, using erlotinib-d6 as internal standard. The procedure method was validated for selectivity, sensitivity, precision, lower limit of detection, linearity and accuracy. The within and between run precisions including the lower limit of quantification did not exceed 12.5%, while the accuracy ranged from 103 to 106%. A weak correlation between hair and plasma concentration was found (R² = 0.48). Furthermore, a large inter-individual variability was noted in the disposition of both plasma and hair samples. The highest hair concentrations were observed in black hair compared with other (grey and brown) hair colors. Generally, a linear reduction in hair concentration was found from proximal to distal hair segments. Additional in vitro experiments suggest an accelerated degradation of erlotinib in hair by artificial UV light and also wash-out by shampoo mixtures pretreatment compared with control samples. In conclusion, a reliable and robust LC-MS/MS method was developed to quantify erlotinib in hair. However, clinical and in vitro evaluations showed that the method is not suitable for monitoring long-term erlotinib exposure. The pitfalls of this application outweigh the current benefits.

Objective measures of non-adherence in cardiometabolic diseases: a review focused on urine biochemical screening

Cardiometabolic diseases are among the most prevalent and harmful conditions worldwide. They are complex, comorbid conditions that require polypharmacy - a known contributor to non-adherence in cardiovascular disease (CVD) and diabetes mellitus (DM). Suboptimal adherence is associated with poor disease control, which increases the risk of hospitalizations, mortality, and preventable financial implications. However, until recently, the lack of a gold standard for non-adherence testing in cardiometabolic diseases has been the major barrier for understanding true prevalence and mortality consequences. Recent European guidelines have endorsed biochemical testing as the preferred measure for non-adherence in CVD, with urinary screening methods being the most clinically widespread. The diagnostic and therapeutic benefits incurred to health service resources by use of biochemical non-adherence testing are vast, as hospitalizations and associated economic burdens are reduced, and tailored therapies are increased. However, biochemical testing can only signify a snap shot of adherence behavior, and true adherence may be skewed by pharmacokinetic factors. This review summarizes current literature regarding the prevalence, impact, and reasons of non-adherence in cardiometabolic disease. The benefits of current adherence diagnostic tools have been appraised, where urine in biochemical testing has been focused upon and evaluated against other matrices.

The Importance of Inhaler Adherence to Prevent COPD Exacerbations

It has been shown that the better outcomes of chronic obstructive pulmonary disease (COPD) are closely associated with adherence to drug therapy, independent of the treatment administered. The clinical trial Towards a Revolution in COPD Health (TORCH) study clearly showed in a three year follow up that patients with good adherence to their inhaler treatment presented a longer time before the first exacerbation, a lower susceptibility to exacerbation and lower all-cause mortality. The Latin American Study of 24-h Symptoms in Chronic Obstructive Pulmonary Disease (LASSYC), a real-life study, evaluated the self-reported inhaler adherence in COPD patients in seven countries in a cross-sectional non-interventional study and found that approximately 50% of the patients had good adherence, 30% moderate adherence and 20% poor adherence. Adherence to inhaler may be evaluated by the specific inhaler adherence questionnaire, the Test of Adherence to Inhalers (TAI). Several factors may predict the incorrect use of inhalers or adherence in COPD outpatient, including the number of devices and the daily dosing frequency. Ideally, patient education, simplicity of the device operation, the use of just one device for multiple medications and the best adaptation of the patient to the inhaler should guide the physician in prescribing the device.