Systolic Blood Pressure and Biochemical Assessment of Adherence: A Cross-Sectional Analysis in the Emergency Department

Comparison of Pharmacy Refill Data With Chemical Adherence Testing in Assessing Medication Nonadherence in a Safety Net Hospital Setting

Background Pharmacy fill data are a practical tool for assessing medication nonadherence. However, previous studies have not compared the accuracy of pharmacy fill data to measurement of plasma drug levels, or chemical adherence testing (CAT). Methods and Results We performed a cross-sectional study in patients with uncontrolled hypertension in outpatient clinics in a safety net health system. Plasma samples were obtained for measurement of common cardiovascular drugs, including calcium channel blockers, thiazide diuretics, beta blockers, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, and statins, using liquid chromatography mass spectrometry. Proportion of days covered (PDC), a method for tracking pharmacy fill data, was calculated via linkages with Surescripts, and its diagnostic test characteristics were compared with CAT. Among 77 patients with uncontrolled hypertension, 13 (17%) were nonadherent to at least 1 antihypertensive drug and 23 (37%) were nonadherent to statins by CAT. PDC was significantly lower in the nonadherent versus the adherent group by CAT only among patients prescribed an angiotensin-converting enzyme inhibitor/angiotensin receptor blocker or statin (all P<0.05) but not in patients prescribed other drug classes. The sensitivity and specificity of PDC in detecting nonadherence to angiotensin-converting enzyme inhibitors/angiotensin receptor blockers and statin drugs by CAT were 75% to 82% and 56% to 79%, respectively. The positive predictive value of PDC in detecting nonadherence was only 11% to 27% for antihypertensive drugs and 45% for statins. Conclusions PDC is useful in detecting nonadherence to angiotensin-converting enzyme inhibitors/angiotensin receptor blockers and statins but has limited usefulness in detecting nonadherence to calcium channel blockers, beta blockers, or thiazide diuretics and has a low positive predictive value for all drug classes.

Blood Pressure Assessment and Treatment in the Observation Unit

PURPOSE OF REVIEW

To review the pathophysiology, diagnosis, and the management of hypertension. Given the paucity of literature regarding the role of the observation unit in the management of hypertension, we will provide our recommendations based on our experience working in an observation unit.

RECENT FINDINGS

Many patients have limited access to primary care, and hypertension diagnosis often relies on office-based measurements. We will describe situations where that is not necessary to make the diagnosis. We will discuss the current non-pharmacologic treatment guidelines, the education of which should be provided to patients both in the emergency department and observation units. We will provide the current recommendations on what anti-hypertension medications can be initiated in the emergency department and observation units. Hypertension is a leading cause of morbidity and mortality in the USA. The utility of an observation unit in the diagnosis and management of patients with hypertension is beneficial particularly for those with risk factors for atherosclerotic disease. An observation unit stay provides the opportunity to diagnosis hypertension, initiate lifestyle education and pharmacologic treatment if indicated, and help to arrange appropriate follow-up for ongoing management and treatment in individuals with limited access to care.

Feasibility and Short-Term Effects of a Multi-Component Emergency Department Blood Pressure Intervention: A Pilot Randomized Trial

Background

Emergency department (ED) visits can be opportunities to address uncontrolled hypertension. We sought to compare short‐term blood pressure measures between the Vanderbilt Emergency Room Bundle (VERB) intervention and usual care plus education.

Methods and Results

We conducted a randomized trial of 206 adult patients with hypertension and elevated systolic blood pressure (SBP) presenting to 2 urban emergency departments in Tennessee, USA. The VERB intervention included educational materials, a brief motivational interview, pillbox, primary care engagement letter, pharmacy resources, and 45 days of informational and reminder text messages. The education arm received a hypertension pamphlet. After 78 participants were enrolled, text messages requested confirmation of receipt. The primary clinical outcome was 30‐day SBP. The median 30‐day SBP was 122 and 126 mm Hg in the VERB and education arms, respectively. We estimated the mean 30‐day SBP to be 3.98 mm Hg lower in the VERB arm (95% CI, −2.44 to 10.4; P=0.22). Among participants enrolled after text messages were adapted, the respective median SBPs were 121 and 130 mm Hg, and we estimated the mean 30‐day SBP to be 8.57 mm Hg lower in the VERB arm (95% CI, 0.98‒16.2; P=0.027). In this subgroup, the median response rate to VERB text messages was 56% (interquartile range, [26%‒80%]).

Conclusions

This pilot study demonstrated feasibility and found an improvement in SBP for the subgroup for whom interactive messages were featured. Future studies should evaluate the role of interactive text messaging as part of a comprehensive emergency department intervention to improve blood pressure control.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02672787.

Medication Adherence and Blood Pressure Control: A Scientific Statement From the American Heart Association

The widespread treatment of hypertension and resultant improvement in blood pressure have been major contributors to the dramatic age-specific decline in heart disease and stroke. Despite this progress, a persistent gap remains between stated public health targets and achieved blood pressure control rates. Many factors may be important contributors to the gap between population hypertension control goals and currently observed control levels. Among them is the extent to which patients adhere to prescribed treatment. The goal of this scientific statement is to summarize the current state of knowledge of the contribution of medication nonadherence to the national prevalence of poor blood pressure control, methods for measuring medication adherence and their associated challenges, risk factors for antihypertensive medication nonadherence, and strategies for improving adherence to antihypertensive medications at both the individual and health system levels.

Antihypertensive medication adherence trends by sex and drug class: A pilot study

Introduction

Antihypertensive medication nonadherence is a prevalent issue but is very difficult to accurately assess. To clarify this problem among hypertensive patients attending a cardiovascular disease outpatient clinic, we utilized high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS) to assess antihypertensive medication adherence and identify trends by sex and drug class.

Methods

Serum was extracted from blood samples obtained from patients with either drug-controlled or drug resistant hypertension (RHTN) and analyzed via HPLC-MS for antihypertensive drugs which were categorized by drug class as beta blockers, aldosterone antagonists, diuretics, ACE inhibitor/ARBs, or calcium channel blockers. Clinic blood pressure (BP), sex, and prescription regimens were extracted from medical records at or near the time of blood collection. "Adherence" or "nonadherence" was determined by comparison of the patient's prescribed drug regimen and the presence/absence of prescribed drug(s) in their serum.

Results

Among 76 patients (47 women; mean age 63; 53% white), nonadherence was confirmed in 29%. RHTN was more frequently identified in women than men (55% vs 38%) and nonadherence was higher in women than men (34% vs 21%). BP in those who were adherent to prescribed antihypertensive drugs was significantly lower than in those who were nonadherent (129/75 vs 145/83 mmHg, p = 0.0015). Overall, ACE inhibitors/ARBs were associated with the least nonadherence. Among women, nonadherence was highest for aldosterone antagonists, whereas among men, nonadherence was highest for diuretics.

Conclusion

We observed nonadherence was more frequent among older women in a cohort of HTN and RHTN patients with cardiovascular disease based on HPLC-MS confirmed drug levels.

Is there any Hope for Monitoring Adherence in an Efficient and Feasible Way for Resistant Hypertension Diagnosis and Follow-Up?

PURPOSE OF REVIEW

Non-adherence to antihypertensive treatment is highly prevalent and represents a major factor affecting their effectiveness in hypertensive patients, thus contributing to apparent treatment resistance. It is however often overlooked because the methods to assess non-adherence are mainly subjective, limiting their usefulness in clinical practice. Non-adherence to treatment affects daily patient management, resulting in inappropriate, costly, and potentially harmful treatments and loss of the expected benefits from antihypertensive drugs.

RECENT FINDINGS

Specialized centers now use a combination of objective screening tools. Firstly, snapshots of adherence levels can be provided by analytical drug detection in various biological matrixes using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and secondly electronic monitoring systems of drug delivery which provide longitudinal data on adherence. Routine utilization of those tools allows the detection of non-adherence in patients with resistant hypertension, thus enabling implementation of appropriate interventions to improve drug adherence and avoid unnecessary treatment intensification. Other complementary techniques, such as digital health feedback system with ingestible sensors, are currently evaluated. In the context of an increasing burden of uncontrolled and apparent treatment-resistant hypertension, detecting non-adherence to antihypertensive therapy is, as acknowledged by the latest guidelines, a top priority to implement in clinical practice but still faces medical conservatism and disbelief.

Drug nonadherence is a common but often overlooked cause of hypertensive urgency and emergency at the emergency department

OBJECTIVES

Over 70% of patients who visit the emergency department with a hypertensive emergency or a hypertensive urgency have previously been diagnosed with hypertension. Drug nonadherence is assumed to play an important role in development of hypertensive urgency and hypertensive emergency, but exact numbers are lacking. We aimed to retrospectively compare characteristics of patients with hypertensive urgency and hypertensive emergency and to prospectively quantify the attribution of drug nonadherence.

METHODS

We retrospectively analysed clinical data including information on nonadherence obtained by treating physicians of patients with SBP at least 180 mmHg and DBP at least 110 mmHg visiting the emergency department between 2012 and 2015. We prospectively studied drug adherence among patients admitted to the emergency department with severely elevated BP by measuring plasma drug levels using liquid chromatography tandem mass spectrometry from September 2016 to March 2017.

RESULTS

Of the 1163 patients retrospectively analysed, 257 (22.0%) met the criteria for hypertensive urgency and 356 (30.6%) for hypertensive emergency. Mean SBP (SD) was 203 (19) mmHg and mean DBP 121 (12) mmHg. Mean age was 60.1 (14.6) years; 55.1% were men. In 6.3% of patients with hypertensive urgency or hypertensive emergency, nonadherence was recorded as an attributing factor. Of the 59 patients prospectively analysed, 18 (30.5%) were nonadherent for at least one of the prescribed antihypertensive drugs.

CONCLUSION

Hypertensive urgency and hypertensive emergency are common health problems resulting in frequent emergency department admissions. Workup of patients with a hypertensive urgency or hypertensive emergency should include an assessment of drug adherence to optimize treatment strategy.

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.

ADHERENCE TO ANTIHYPERTENSIVE MEDICATION, PRESSORIC CONTROL AND ASSOCIATED FACTORS IN PRIMARY HEALTH CARE

ABSTRACT Objective: to evaluate adherence to antihypertensive medication, blood pressure levels, and associated factors in hypertensive individuals monitored by primary health care. Method: a cross-sectional, descriptive and analytical study, carried out in Family Health Strategies in the city of Recife, Brazil. Data collection took place from April to August 2018. To assess adherence, the Morisky Medication Adherence Scale was used, an 8-item scale that addresses some behaviors when taking antihypertensive medication, such as: forgetfulness, non-intentional intake, reduced dose, interruption of treatment, and discomfort following the prescription. In the data analysis, the Chi-square and Kruskal-Wallis tests were used. Results: a total of 421 hypertensive individuals participated in the study. Low, medium and high adherence was observed, respectively, at 48.5%, 38.7% and 12.8%. High/Medium adherence was associated with single individuals (p=0.005), without work activity (p=0.043), who did not report stress (p=0.001) and hypertensive urgency/emergency (p=0.037), without side effects of antihypertensive drugs (p=0.012), and who made continuous use of other drugs (p=0.001). Blood pressure control was verified in 205 hypertensive individuals and an association was established with females (p=0.033), younger age (p=0.041), higher schooling (p=0.008), use of up to 2 antihypertensive drugs (p=0.006) and absence of side effects (p=0.026). Conclusion: the predominance of low adherence and uncontrolled pressure in some groups show the need to redirect health promotion actions in primary care, especially in the program for people with arterial hypertension and diabetes mellitus.

Resistant hypertension-defining the scope of the problem

The updated scientific statement by the American Heart Association has defined resistant hypertension (HTN;RH) as uncontrolled blood pressure (BP) ≥ 130/80 mmHg, despite concurrent use of 3 anti-HTN drug classes comprising a calcium channel blocker, a blocker of renin-angiotensin system, and a thiazide diuretic, preferably chlorthalidone. Using the updated BP criteria, the prevalence of RH in the United States is found to be modestly increased by approximately 3-4% among treated population. Meta-analysis of observational studies have demonstrated that pseudo-RH from white coat HTN or medication nonadherence is as much common as the truly RH. Thus, screening for pseudo-resistance in the evaluation of all apparent RH is of utmost importance as diagnosis of white-coat HTN requires no treatment, while medication nonadherence would benefit from identifying and targeting barriers to adherence.

Opportunities and Challenges in Cardiovascular Pharmacogenomics: From Discovery to Implementation

This review will provide an overview of the principles of pharmacogenomics from basic discovery to implementation, encompassing application of tools of contemporary genome science to the field (including areas of apparent divergence from disease-based genomics), a summary of lessons learned from the extensively studied drugs clopidogrel and warfarin, the current status of implementing pharmacogenetic testing in practice, the role of genomics and related tools in the drug development process, and a summary of future opportunities and challenges.

Improving Blood Pressure Among African Americans With Hypertension Using a Mobile Health Approach (the MI-BP App): Protocol for a Randomized Controlled Trial

BACKGROUND

African Americans shoulder significant disparities related to hypertension (HTN), which is a serious public health problem in the city of Detroit, Michigan, where more than 80% of the population is African American. Connectivity through smartphones, use of home blood pressure (BP) monitoring, and newly developed mobile health (mHealth) interventions can facilitate behavioral changes and may improve long-term self-care for chronic conditions, but implementation of a combined approach utilizing these methods has not been tested among African American patients with uncontrolled HTN. Since African Americans are more likely than other racial or ethnic subgroups to utilize the emergency department (ED) for ambulatory care, this presents an opportunity to intervene on a population that is otherwise difficult to reach.

OBJECTIVE

The MI-BP app aims to reduce health disparities related to HTN in the community by employing a user-centered intervention focused on self-BP monitoring, physical activity, reduced sodium intake, and medication adherence. We seek to test the efficacy of MI-BP, an mHealth app for HTN self-management, on BP control (primary aim), physical activity, sodium intake, and medication adherence (secondary aim) in African Americans with HTN. This study also seeks to evaluate the cost-effectiveness of MI-BP when compared with usual care methods.

METHODS

This is a 1-year randomized controlled trial that will recruit individuals who have uncontrolled HTN from 2 EDs in the city of Detroit, with a planned sample size of 396 randomized participants. To be eligible for inclusion, potential participants must be African American, 25 to 70 years old, previously diagnosed with HTN, have a smartphone compatible with MI-BP, and have uncontrolled BP at triage and on repeat measurement at least 1-hour post triage vitals. Once a participant is deemed eligible, all study procedures and subsequent follow-up visits (8 in total) are conducted at the Wayne State University Clinical Research Service Center. We seek to determine the effect of MI-BP on BP for 1 year (using BP control and mean systolic BP as coprimary outcomes and physical activity, sodium intake, and medication adherence as secondary outcomes) compared with usual care controls.

RESULTS

Recruitment for this study began in January 2018. The study will continue through 2021.

CONCLUSIONS

As the first of its kind conducted in an ED setting, MI-BP was designed to document the efficacy and acceptability of a multicomponent mHealth approach to help African Americans with uncontrolled BP modify their lifestyle to better manage their HTN. We expect to lay the foundation to sustainably reduce HTN-related health disparities through better integration of multiple behavior self-monitoring and improve outcomes for those who traditionally rely on the ED for chronic disease care.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02360293; http://clinicaltrials.gov/ct2/show/NCT02360293.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR1-10.2196/12601.

Direct assessment of adherence and drug interactions in patients with hypertensive crisis-A cross-sectional study in the Emergency Department

Though drug adherence is supposed to be low in hypertensive crisis (HTN-C), there are no data available from direct adherence assessments. The aim of the present study was to evaluate adherence to prescribed antihypertensives and potential interactions of concomitant drugs and foods with prescribed antihypertensives in patients with HTN-C by a direct evaluation via biochemical urine analysis. In the present cross-sectional study, 100 patients with HTN-C, admitted to the emergency department (ED), were included. A biochemical urine analysis using gas chromatography-tandem mass spectrometry was performed. Out of 100 patients, 86 received antihypertensives. Urine analyses could be evaluated unambiguously in 62 patients. In 15 of these 62 patients (24%), a nonadherence could be demonstrated, and in 21 patients (34%), a partial nonadherence could be demonstrated. Patients with nonadherence or partial nonadherence showed a longer hypertension history (15[5-22] vs 10[3-15] years, P = 0.04) were prescribed more general medication (number 7.1 ± 3.4 vs 3.4 ± 1.8; P < 0.01) as well as antihypertensive drugs (number 2.8 ± 1.1 vs 1.5 ± 0.7, P < 0.01). A potential BP-raising trigger by medications or food interaction was frequently detectable, predominantly with nonsteroidal anti-inflammatory drugs (NSAIDs; n = 38), glucocorticoids (n = 8), antidepressants (n = 10), and licorice (n = 10). Nonadherence and partial nonadherence to prescribed antihypertensives might play a crucial role for the occurrence of HTN-C. However, further case-controlled studies are needed to confirm the present findings. Ingestion of concurrent over-the-counter drugs such as NSAIDs but also prescribed drugs as well as aliments may lead to critical BP elevation. In order to prevent HTN-C, the present findings emphasize the importance for clinicians to pay attention to the issue of adherence and co-medication.

Assessment of Patient Medication Adherence, Medical Record Accuracy, and Medication Blood Concentrations for Prescription and Over-the-Counter Medications

IMPORTANCE

Inaccurate medication records and poor medication adherence result in incomplete knowledge of therapy for patients.

OBJECTIVE

To study accuracy of medical records and patient adherence by measuring blood concentrations of medications.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study validated a serum-based liquid chromatography-tandem mass spectrometry assay to simultaneously quantify 263 medications used for acute and chronic conditions. The assay panel was applied to 3 clinical patient cohorts: residual serum from 1000 randomly selected samples sent for routine clinical chemistry testing between April 8 and October 6, 2015 (residuals cohort), 50 prospectively enrolled patients in a gastroenterology clinic between March 1 and March 15, 2016, who were prescribed more than 5 medications (gastroenterology care cohort), and a convenience cohort of 296 patients with hypertension who sought care in an emergency department (ED care cohort) between July 1, 2012, and April 25, 2013. Integrated data analysis of the cohorts was performed from August 22 to November 29, 2017.

MAIN OUTCOMES AND MEASURES

Medication serum concentrations, electronic health record medication lists, and predicted drug interactions.

RESULTS

Of the 1346 total samples, 1000 came from the residuals cohort (640 women and 360 men; median age, 60 years [interquartile range (IQR), 44-71 years]), 50 from the gastroenterology care cohort (30 women and 20 men; median age, 66 years [IQR, 62-70 years]), and 296 from the ED care cohort (160 women and 136 men; median age, 59 years [IQR, 52-66 years]). Median medication adherence, defined as the subset of detected medications from the prescription record, was 83% (IQR, 50%-100%) in the residuals cohort, 100% (IQR, 84%-100%) in the gastroenterology care cohort, and 78% (IQR, 57%-100%) in the ED care cohort. Patients adherent to 1 medication were more often adherent to other medications. Among patients prescribed 3 medications or more, there were no significant associations between medication adherence and sex or number of prescribed medications, and there was a modest association between adherence and age. By comparing detected vs prescribed medications, we detected a median of 0 (IQR, 0-2) medications per patient that were not listed in the electronic health record in the residuals cohort, 1 (IQR, 0-2) medication per patient that was not listed in the electronic health record in the gastroenterology care cohort, and 1 (IQR, 0-2) medication per patient that was not listed in the electronic health record in the ED care cohort. A total of 435 patients (43.5%) in the residuals cohort had no discrepancy between the electronic health record and detected medication lists, 22 patients (44.0%) in the gastroenterology care cohort had no discrepancy between the electronic health record and detected medication lists, and 41 patients (13.9%) in the ED care cohort had no discrepancy between the electronic health record and detected medication lists. Half of adverse drug reaction alerts occurred among medications detected without prescription.

CONCLUSIONS AND RELEVANCE

Comprehensive medication monitoring offers promise to improve adherence, the accuracy of medical records, and the safety for patients with polypharmacy.

Characteristics and treatment of African-American and European-American patients with resistant hypertension identified using the electronic health record in an academic health centre: a case-control study

OBJECTIVE

To identify patients with hypertension with resistant and controlled blood pressure (BP) using electronic health records (EHRs) in order to elucidate practices in the real-world clinical treatment of hypertension and to enable future genetic studies.

DESIGN

Using EHRs, we developed and validated algorithms to identify patients with resistant and controlled hypertension.

SETTING

An academic medical centre in Nashville, Tennessee.

POPULATION

European-American (EA) and African-American (AA) patients with hypertension.

MAIN OUTCOME MEASURES

Demographic characteristics: race, age, gender, body mass index, outpatient BPs and the history of diabetes mellitus, chronic kidney disease stage 3, ischaemic heart disease, transient ischaemic attack, atrial fibrillation and sleep apnoea.

MEDICATION TREATMENT

All antihypertensive medication classes prescribed to a patient at the time of classification and ever prescribed following classification.

RESULTS

The algorithms had performance metrics exceeding 92%. The prevalence of resistant hypertension in the total hypertensive population was 7.3% in EA and 10.5% in AA. At diagnosis, AA were younger, heavier, more often female and had a higher incidence of type 2 diabetes and higher BPs than EA. AA with resistant hypertension were more likely to be treated with vasodilators, dihydropyridine calcium channel blockers and alpha-2 agonists while EA were more likely to be treated with angiotensin receptor blockers, renin inhibitors and beta blockers. Mineralocorticoid receptor antagonists use was increased in patients treated with more than four antihypertensive medications compared with patients treated with three (12.4% vs 2.6% in EA, p<0.001; 12.3% vs 2.8% in AA, p<0.001). The number of patients treated with a mineralocorticoid receptor antagonist increased to 37.4% in EA and 41.2% in AA over a mean follow-up period of 7.4 and 8.7 years, respectively.

CONCLUSIONS

Clinical treatment of resistant hypertension differs in EA and AA patients. These results demonstrate the feasibility of identifying resistant hypertension using an EHR.

Indexed plasma drug concentrations for drug adherence screening in hypertensive patients

AIM

Due to its high sensitivity, qualitative plasma drug screening by liquid chromatography/tandem mass spectrometry may not be able to distinguish same-day drug intake from drug use on preceding days and cause misclassifications of drug adherence in hypertensive patients. Analysis of plasma drug concentrations may provide more accurate results.

PATIENTS AND METHODS

We describe dose-dependent indexing of plasma drug concentrations for expected peak concentrations to define individual screening thresholds for same-day drug use. To explore its utility, plasma samples from 9 hypertensive patients without major comorbidity were prospectively analyzed on two occasions. All were on hydrochlorothiazide with either amlodipine (n=7) and/or valsartan (n=6) at different doses. Drugs were quantitated by mass spectrometry. Non-adherence was defined if an indexed drug concentration was below the expected trough level at 24-hour dosing interval.

RESULTS

All patients were adherent by qualitative plasma screening (spectrometric sensitivity). On the first visit (random sampling time), mean plasma concentrations of the drugs were 102±70, 15.4±6.7 and 2529±1608ng/mL, and mean indexes 84±57%, 85±35% and 60±38%, respectively. Using the study criterion, non-adherence was suspected in three. Intraindividual cross-checking retained two. On the second visit (fixed sampling time), amlodipine concentration was 15.6±8.5ng/mL (88±52% after indexing). Two patients were non-adherent according to the study criterion.

CONCLUSION

Indexing of plasma drug concentrations appears practicable and useful for drug adherence screening under clinical conditions. With this technique, same-day drug intake can be easily distinguished which reduces the risk of false positive results associated with qualitative drug screening.

Advancing the Science and Practice of Medication Adherence

Medication adherence remains a significant unmet challenge for optimizing patient outcomes. Recent advances in the conceptualization, measurement, and support of medication adherence offer fresh opportunities to make a meaningful impact on adherence-related behavior and outcomes. These advances emphasize the multifaceted and dynamic nature of medication adherence, provide novel methods for monitoring medication adherence in clinical care, and articulate a set of multilevel strategies to more effectively improve and sustain medication adherence. Here, we offer recommendations for how clinicians can better engage with, and benefit from, these innovations to improve patient medication adherence and associated treatment outcomes.

Medication adherence during laboratory workup for primary aldosteronism: pilot study

PURPOSE

Current hypertension guidelines stipulate that all incompatible medications be stopped before performing laboratory screening for aldosteronism, but patient adherence is unclear. We measured plasma drug concentrations to determine drug adherence and potential drug bias during biochemical tests.

PATIENTS AND METHODS

Plasma concentrations of 10 antihypertensive drugs were quantified by mass spectrometry in 24 consecutive ambulatory patients with uncontrolled hypertension routinely evaluated for aldosteronism. Drug screening was done before (first visit), and on the day of biochemical tests (second visit) after stopping all incompatible medications. Concentrations above those expected at trough dosing interval defined same-day dose intake.

RESULTS

On the first and second visits, 76% vs 77% of prescribed antihypertensive doses could be verified in plasma. A total of 33% of patients were found to be nonadherent and showed divergent plasma drug results relative to prescriptions (21% drugs not detected/13% unprescribed drugs found) on first visit, 25% on the second (0%/25%), and 46% for both. A total of 21% used medication incompatible with the biochemical tests on the second visit. Moreover, 17% of drug concentrations were below expected trough levels on the first vs 15% on the second visit. This analysis revealed additional four (17%) vs three (13%) nonadherent patients who failed same-day dose intake and remained undetected by qualitative drug tests.

CONCLUSION

Nonadherence was frequent during laboratory evaluations for aldosteronism advocating cautious interpretation of results. A multicenter study is desirable to set the stage for new screening protocols that should incorporate also incentives and checks of drug adherence.