Adherence and persistence with branded antidepressants and generic SSRIs among managed care patients with major depressive disorder

Sociodemographic and clinical predictors of adherence to antidepressants in depressive disorders: a systematic review with a meta-analysis

Introduction: Current evidence reveals concerning rates of non-adherence to antidepressant treatment, possibly influenced by various relevant determinants such as sociodemographic factors or those related to the health system and their professionals. The aim of this paper is to review the scientific evidence on sociodemographic and clinical predictors of adherence to pharmacological treatment in patients diagnosed with a depressive disorder. Methods: a systematic review (SR) was conducted. The search for a previous SR was updated and de novo searches were performed in Medline, EMBASE, Web of Science (WoS) and PsycInfo (last 10 years). The risk of bias was assessed using the Cochrane tool for non-randomized studies-of Exposure (ROBINS-E). Meta-analyses were conducted. Results: Thirty-nine studies (n = 2,778,313) were included, 24 of them in the meta-analyses. In the initiation phase, no association of adherence was found with any of the predictors studied. In the implementation and discontinuation phases, middle-aged and older patients had better adherence rates and lower discontinuation rates than younger ones. White patients adhered to treatment better than African-American patients. Discussion: Age and ethnicity are presented as the predictive factors of pharmacological adherence. However, more research is needed in this field to obtain more conclusive results on other possible factors. Systematic Review Registration: [https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023414059], identifier [CRD42023414059].

Does China's competitive generic substitution policy deliver equivalent clinical outcomes? A pilot study with two generic formulations of olanzepine

With the National Centralized Drug Procurement policy gradually applied nationally in China, concerns about the effectiveness and safety of bid-winning generic drugs are growing again, but relevant studies are lacking. This real-world, before-and-after study was conducted to explore the clinical effects of switching between two versions of generic olanzapine (one of them was bid-winning product). Pre-and post-switching serum olanzapine concentrations were compared. A total of 30 patients were included and results showed the log-transformed, dose-adjusted concentration of bid-winning generic olanzapine was significantly lower than that of another generic olanzapine, while no significant differences were shown on Clinical Global Impressions Severity of Illness or Improvement ratings before and after switching. This study suggest that a generic version of a psychotropic medication may not be of therapeutic equivalence or bioequivalence with another generic one. Changes in efficacy or tolerability are possible in every switch. Therapeutic drug monitoring could be a valuable tool during switches between generic drugs. Larger prospective clinical studies for other generic psychotropic medications in target populations are warranted.

Incremental burden of relapse in patients with major depressive disorder: a real-world, retrospective cohort study using claims data

BACKGROUND

Relapse is common in major depressive disorder (MDD). In this study, we evaluated the incremental health care burden of relapse in patients with MDD.

METHODS

This real-world retrospective cohort study used administrative medical and pharmacy claims data to identify commercially insured adult patients in the United States diagnosed with MDD who initiated a new antidepressant between January 1, 2012, and September 30, 2017. All-cause health care resource utilization, total costs, and medication adherence were evaluated in two cohorts: patients with and patients without relapse. Relapse was defined as suicide attempts, psychiatric hospitalization, mental health-related emergency department (ED) visit, use of electroconvulsive therapy, or reinitiation of treatment after a gap ≥6 months.

RESULTS

The study population included 14,186 patients (7093 baseline-matched patients per cohort). The mean follow-up period was 27.5 and 26.0 months for patients with and patients without relapse, respectively. Patients with relapse had significantly higher rates of hospitalization (16.6% vs 8.5%; p < .0001) and ED visits (54.8% vs 34.7%; p < .0001) than patients without relapse. The total costs for patients with relapse were significantly higher ($12,594 vs $10,445;  p < .0001). Patients with relapse were also less adherent to antidepressants (mean proportion of days covered, 0.43 vs 0.49; p < .0001).

CONCLUSIONS

Relapse of MDD was associated with increased total costs and health care utilization and lower adherence to antidepressants. Reducing the risk of relapse may result in a reduction of the associated health care burden; however, findings may only be generalizable to patients with commercial insurance.

Adherence to Desvenlafaxine Versus Usual Care and Its Impact on Health Outcomes: A Comparative Real-world Clinical Study

BACKGROUND AND OBJECTIVE

Low adherence to treatment is associated with poorer clinical outcome and greater healthcare resources utilization (HRU). Limited data are available on the extent of adherence to each individual antidepressant. The goal of this study was to compare the adherence rate to desvenlafaxine versus usual care with selective serotonin reuptake inhibitors (SSRI) and/or other serotonin-norepinephrine reuptake inhibitors (SNRI), in subjects with major depressive disorder (MDD).

METHODS

Retrospective, multi-centric, observational study including 574 outpatients with MDD. Data were collected from mental and primary care centers. Adherence, persistence, effectiveness, and HRU was evaluated through multivariate regression models.

RESULTS

At 12-months, adjusted adherence rate was higher with desvenlafaxine versus SNRI/SSRI, 67.9% versus 59.9% (OR 1.66, 95% CI 1.07-2.59, p = 0.024). Remission rate was numerically higher with desvenlafaxine versus SNRI/SSRI, 55.9% versus 50.1% (OR 1.35, 95% CI 0.93-1.98, p = 0.118), as well as treatment response, 76.5% in desvenlafaxine group versus 70.8% in SNRI/SSRI group (OR 1.25, 95% CI 0.82-1.90, p = 0.300). Medical visits use was higher in SNRI/SSRI than in desvenlafaxine group [9.8 (4.8) versus 9.1 (6.0), p = 0.019].

CONCLUSIONS

Desvenlafaxine is significantly associated with a higher adherence rate at 12 months compared to usual care based on SSRI or other SNRI. This suggests that desvenlafaxine could improve disease management having a positive impact on disease-associated costs.

Simultaneous Benzodiazepine and SSRI Initiation in Young People With Anxiety Disorders

Objective: There are potential risks and benefits of combining benzodiazepine (BZD) and selective serotonin reuptake inhibitor (SSRI) therapy at anxiety disorder treatment onset. We investigated how often adolescents and young adults with anxiety disorders simultaneously initiate BZD treatment with SSRI treatment and examined whether SSRI treatment duration varies by simultaneous BZD initiation. Methods: In a United States commercial claims database (January 2008-December 2016), we identified adolescents (10-17 years) and young adults (18-24 years) with ICD-9-CM/ICD-10-CM anxiety disorder diagnoses initiating SSRI treatment, without past-year SSRI and BZD treatment. We defined simultaneous initiation as filling a new BZD prescription on the date of SSRI initiation. We estimated time to SSRI treatment discontinuation and used stabilized inverse probability of treatment weighting for adjusted estimates. Results: The study included 94,399 adolescents and 130,971 young adults initiating SSRI treatment with an anxiety disorder. Four percent of adolescents and 17% of young adults simultaneously initiated BZD treatment, varying by age, anxiety disorder, comorbidities, health care utilization, and provider type. Simultaneous BZD initiation among SSRI initiators declined from 2008 to 2016. SSRI treatment duration was similar in initiators of simultaneous therapy vs SSRI monotherapy: ≥ 6 months in adolescents (55% vs 56%, respectively) and in young adults (39% vs 40%). Nine percent of simultaneous initiators continued BZDs for ≥ 6 months. Conclusions: Simultaneous initiation of BZD and SSRI treatment is relatively common in young adults with anxiety disorders and was not associated with longer SSRI persistence. Given risks of BZD treatment, potential benefits and risks of adding a BZD at SSRI treatment initiation must be carefully weighed.

Analysis of treatment cost and persistence among migraineurs: A two-year retrospective cohort study in Pakistan

Objectives

The persistence pattern of anti-migraine drugs’ use among migraineurs is very low in the United States and different European countries. However, the cost and persistence of antimigraine drugs in Asian countries have not been well-studied. Hence, the present study aimed to evaluate the treatment cost and persistence among migraineurs in Pakistan.

Methods

Data from prescriptions collected from migraineurs who visited the Outpatient Department (OPD) of different public and private sector tertiary-care hospitals of Karachi, Pakistan were used to conduct this retrospective cohort study from 2017 to 2019. The minimum follow up period for each migraineur was about 12 months for persistence analysis while dropped-out patients data were also included in survival analysis as right censored data. Pairwise comparisons from Cox regression/hazards ratio were used to assess the predictors of persistence with the reference category of non-binary variables i.e. hazard ratio = 1 for low frequency migraineurs and NSAIDs users. Persistence with anti-migraine drugs was estimated using the Kaplan-Meier curve along with the Log Rank test.

Results

A total of 1597 patients were included in this study, 729 (45.6%) were male and 868 (54.3%) were female. Non-steroidal anti-inflammatory drugs (NSAIDs) were the most prescribed class of drug initially for all classes of migraineurs (26.1%). Of them, 57.3% of migraineurs discontinued their treatment, 28.5% continued while 14.8% were switched to other treatment approaches. Persistence with initial treatment was more profound in female (58.8%) patients compared to males while the median age of continuers was 31 years. The total cost of migraine treatment in the entire study cohort was 297532.5 Pakistani Rupees ($1901.1). By estimating the hazard ratios (HR) using the Cox regression analysis, it can be observed that patients with high frequency (HR, 1.628; 95%CI, 1.221–2.179; p<0.0001) migraine, depression (HR, 1.268; 95%CI, 1.084–1.458; p<0.0001), increasing age (HR, 1.293; 95%CI, 1.092–1.458; p<0.0001), combination analgesics (HR, 1.817; 95%CI, 0.841–2.725; p = 0.0004) and prophylaxis drugs (HR, 1.314; 95%CI, 0.958–1.424; p<0.0001) users were at a higher risk of treatment discontinuation. However, patients with chronic migraine (HR, 0.881; 95%CI, 0.762–0.912; p = 0.0002), epileptic seizure (HR, 0.922; 95%CI, 0.654–1.206; p = 0.0002), other comorbidities (HR, 0.671; 95%CI, 0.352–1.011; p = 0.0003) and users of triptan(s) (HR, 0.701; 95%CI, 0.182–1.414; p = 0.0005) and triptan(s) with NSAIDs (HR, 0.758; 95%CI, 0.501–1.289; p<0.0001) had more chances to continue their initial therapy.

Conclusion

Similar to western countries, the majority of migraineurs exhibited poor persistence to migraine treatments. Various factors of improved persistence were identified in this study.

Effects of dose titration on adherence and treatment duration of pregabalin among patients with neuropathic pain: A MarketScan database study

OBJECTIVE

To examine pregabalin dose titration and its impact on treatment adherence and duration in patients with neuropathic pain (NeP).

METHODS

MarketScan database (2009-2014) was used to extract a cohort of incident adult pregabalin users with NeP who had at least 12 months of follow-up data. Any dose augmentation within 45 days following the first pregabalin claim was defined as dose titration. Adherence (measured by medication possession ratio/MPR) and persistence (measured as the duration of continuous treatment) were compared between the cohorts with and without dose titration. Logistic regressions and Cox proportional hazards models were used to identify the factors associated with adherence (MPR ≥ 0.8) and predictors of time to discontinuation.

RESULTS

Among the 5,186 patients in the analysis, only 18% of patients had dose titration. Patients who had dose titration were approximately 2.6 times as likely to be adherent (MPR ≥ 0.8) (odds ratio = 2.59, P < 0.001) than those who did not have dose titration. Kaplan-Meier analysis shows that the time to discontinuation or switch was significantly longer among patients who had dose titration (4.99 vs. 4.04 months, P = 0.009).

CONCLUSIONS

Dose titration was associated with improved treatment adherence and persistence among NeP patients receiving pregabalin. The findings will provide valuable evidence to increase physician awareness of dose recommendations in the prescribing information and to educate patients on the importance of titration and adherence.

Influencers of generic drug utilization: A systematic review

INTRODUCTION

With an increase in prescription drug spending and rising drug costs there is a need to encourage the use of generic prescription drugs. However, maximizing generic drug use is not possible without the public's positive perception and meeting their informational needs about generic drugs. Thus, improving the public's confidence in, and knowledge of generic drugs on the market is critical. The objective of this systematic review is to examine and evaluate the studies focusing on the nature and extent of key factors influencing generic drug use in the United States in order to help guide policy, education and practice interventions.

MATERIALS AND METHODS

Using multiple search engines and key word screening criteria, empirical studies published in English between January 1, 2005 and December 31, 2015 were identified. A qualitative synthesis of the evidence identified domains of key factors that influenced generic drug use across studies.

RESULTS

Over 3000 citations met the key word screening criteria; 67 of these met inclusion criteria for the systematic review. Seven domains of factors that influence generic drug utilization were identified: 1) patient-related factors, 2) formulary management or cost containment, 3) healthcare policies, 4) promotional activities, 5) educational initiatives, 6) technology, and 7) physician-related factors.

CONCLUSION

Patients, physicians, pharmacists, formulary managers, and policymakers play an important role in generic drug use. Understanding the factors influencing generic drug use can help guide future policy, education, and practice interventions to increase generic drug use.

A multicenter, open-label, pilot study evaluating the functionality of an integrated call center for a digital medicine system to optimize monitoring of adherence to oral aripiprazole in adult patients with serious mental illness

BACKGROUND

Medication nonadherence is common in the treatment of serious mental illness (SMI) and leads to poor outcomes. The digital medicine system (DMS) objectively measures adherence with oral aripiprazole in near-real time, allowing recognition of adherence issues. This pilot study evaluated the functionality of an integrated call center in optimizing the use of the DMS.

MATERIALS AND METHODS

An 8-week, open-label, single-arm trial at four US sites enrolled adults with bipolar I disorder, major depressive disorder, and schizophrenia on stable oral aripiprazole doses and willing to use the DMS (oral aripiprazole + ingestible event marker [IEM], IEM-detecting skin patch, and software application). Integrated call-center functionality was assessed based on numbers and types of calls. Ingestion adherence with prescribed treatment (aripiprazole + IEM) during good patch wear and proportion of time with good patch wear (days with ≥80% patch data or detected IEM) were also assessed.

RESULTS

All enrolled patients (n=49) used the DMS and were included in analyses; disease duration overall approached 10 years. For a duration of 8 weeks, 136 calls were made by patients, and a comparable 160 calls were made to patients, demonstrating interactive communication. The mean (SD) number of calls made by patients was 2.8 (3.5). Approximately half of the inbound calls made by patients occurred during the first 2 weeks and were software application- or patch-related. Mean ingestion adherence was 88.6%, and corresponding good patch wear occurred on 80.1% of study days.

CONCLUSION

In this pilot study, the integrated call center facilitated DMS implementation in patients with SMI on stable doses of oral aripiprazole. In clinical practice, the call center and the DMS will facilitate objective measurement of adherence and potentially improve rates of adherence in patients with SMI.

Comparative risk of hip fractures in elderly nursing home patients with depression using paroxetine and other selective serotonin reuptake inhibitors

AIM

To evaluate comparative safety of paroxetine and other selective serotonin reuptake inhibitors (SSRIs) for the risk of hip fractures.

PATIENTS & METHODS

A propensity score-matched retrospective cohort study was conducted using 2007-2010 Minimum Data Set linked Medicare data. Robust Cox proportional hazards model was used to evaluate the risk of hip fractures in depressed elderly nursing home residents.

RESULTS

Cox analysis did not find any significant difference in the risk of hip fractures for the paroxetine users (hazard ratio: 1.09; 95% CI: 0.91-1.32) when compared with other SSRIs. Results from the sensitivity analysis supported the main findings.

CONCLUSION

There was no differential risk of hip fractures between paroxetine and other SSRIs. Future studies are needed to evaluate other anticholinergic effects of paroxetine.

Development and application of an aggregate adherence metric derived from population pharmacokinetics to inform clinical trial enrichment

Nonadherence to prescribed medication is a common barrier to effective treatment, and current options to determine adherence are limited. This study describes development of an aggregate adherence measure based on population pharmacokinetics (PK), and its comparison to a subjective questionnaire, the Morisky 8-item medication adherence scale (MMAS8), in a trial of psychiatric patients on stable doses of oral aripiprazole. A comprehensive model was first built using plasma drug concentration data from 24 clinical studies comprising 448 patients with over 13,500 observations. Application of this model to independent patient profiles for a given drug-dosing regimen were used to generate the primary aggregate adherence metric, a ratio of observed versus expected plasma exposures at steady-state. Although the metric is capable of comparing relative adherence across groups, simulations showed that the metric is not sufficiently sensitive as an individual diagnostic in all cases. There were no trends observed between results from calculated aggregate adherence metrics and total scores from MMAS8 in a single-visit clinical trial of 47 patients with bipolar 1 disorder or schizophrenia who were on stable doses of aripiprazole, although a strong association was observed for one MMAS8 question. The range of the metric calculated for patients was between 0.16 and 3.15. The described approach of a novel “reverse” application of population PK to quantify relative adherence with an aggregate measure may be influential for both clinical and pharmacometric communities.

Distribution and trends in outpatient utilization of generic versus brand name psychopharmaceuticals during a ten-year period in Croatia

BACKGROUND

Drug costs increasingly pose a burden upon the otherwise inadequate health care resources and rational drug utilization is an important segment of every national health policy. Optimal patient care should be the goal of rational pharmacotherapy, whereby the economic burden of treatment is just one of the elements to be considered on choosing appropriate therapy.The aim of this study was to determine distribution and trends in the outpatient utilization of generic versus brand name psychopharmaceuticals and to evaluate the rationality of prescribing psychopharmaceuticals during a ten-year period.

METHODS

Using the World Health Organization Anatomical-Therapeutic-Chemical classification/Defined Daily Doses (ATC/DDD) methodology, the number of DDD was calculated from data collected from pharmacies on the number and size of drug packages. The ratio of generic and brand name drug costs served as an indicator on assessing the rationality of drug utilization.

RESULTS

Total cost for psychopharmaceuticals increased by 20.1%, more for brand name than for generic agents (32.7% vs. 7.4%). The highest share of generic psychopharmaceuticals as compared with brand name drugs according to DDD per 1000 inhabitants per day (DDD/1000/day) was in the group of psycholeptics (83.6% in 2001 vs. 82.2% in 2010), most in hypnotics and sedatives, and least in antipsychotics. The share of generic psychopharmaceuticals in total drug utilization according to financial indicators decreased by 9.6% and according to DDD/1000/day by 12%. The greatest decrease was in antidepressants, i.e. by 33.8% according to financial indicators and by 46% according to DDD/1000/day; and in antipsychotics by 30.9% according to DDD/1000/day, while showing an increase by 8.5% according to financial indicators. In the therapeutic subgroup of mood stabilizers, the share of generic drugs in total drug utilization declined by 32% according to DDD/1000/day, but increased by 25.1% according to financial indicators.

CONCLUSIONS

The lack of uniform national guidelines and the still strong impact of pharmaceutical industry marketing continue favoring the rise in prescribing brand name antidepressants and antipsychotics. Depression, schizophrenia and bipolar diseases are complex diseases. As a result, specific measures are needed to encourage the prescribing of generic psychopharmaceuticals.

Duloxetine treatment adherence across mental health and chronic pain conditions

PURPOSE

This study applied a uniform methodology for measuring and comparing duloxetine adherence in the treatment of multiple chronic medical conditions.

MATERIALS AND METHODS

Study patients 18-64 years of age initiating duloxetine therapy during 2008 were identified from a large managed care database. The study was restricted to patients with continuous health plan eligibility for 12 months pre- and post-duloxetine initiation. Study patients had ≥1 medical claim with an inpatient or outpatient diagnosis of one (and only one) of the following conditions: major depressive disorder (MDD); generalized anxiety disorder (GAD); fibromyalgia, diabetic peripheral neuropathic pain; or chronic musculoskeletal pain, as established in studies in patients with osteoarthritis and chronic lower back pain (CLBP). Patients initiating duloxetine who had two or more of the six studied conditions were not included in this study, thereby avoiding the need to differentiate between primary and secondary diagnoses from the claims records. Adherence rate was defined as the percentage of patients with a 365-day medication possession ratio ≥0.8.

RESULTS

A total of 20,490 patients initiated duloxetine treatment during 2008 with a diagnosis of one of the studied conditions during the study period. The adherence rate in our sample was 34.6% and was highest among patients with MDD (37.3%) and lowest for patients with CLBP (29.9%). In general, adherence among patients with MDD and GAD was greater than among those with a chronic pain condition.

CONCLUSION

Adherence among newly initiated duloxetine patients varied modestly across the medical conditions for which it was used. After adjusting for potential confounders, differences between the mental conditions (MDD and GAD) and the chronic pain conditions (CLBP, osteoarthritis, and diabetic peripheral neuropathic pain) were statistically significant. These results may be useful in the determination of expectations of adherence, and how it may differ for each of the conditions studied.

Local control for identifying subgroups of interest in observational research: persistence of treatment for major depressive disorder

Caregivers are regularly faced with decisions between competing treatments. Large observational health care databases provide a golden opportunity for research on heterogeneity in patient response to guide caregiver decisions, due to their sample size, diverse populations, and real-world setting. Local control is a promising tool for using observational data to detect patient subgroups with differential response on one treatment relative to another. While standard data mining approaches find subgroups with optimal responses for a particular population, detecting subgroups that reveal treatment differences while also adjusting for confounding in observational data is challenging. Local control utilizes unsupervised clustering to form non-parametric patient-level counterfactual treatment differences and displays them as an observed distribution of effect-size estimates. Classification and regression trees (CART) then find the factors that drive the greatest outcome differentiation between treatments. In this manuscript, we demonstrate the use of this two-step strategy using local control plus CART to identify depression patients most (least) likely to benefit from treatment with duloxetine relative to extended-release venlafaxine. Prior medication costs and age were found to be factors most associated with differential outcome, with prior medication costs remaining as an important factor after sensitivity analyses using a second dataset.

Trend in SSRI-SNRI antidepressants prescription over a 6-year period and predictors of poor adherence

PURPOSE

To describe antidepressant (AD) use in the Emilia-Romagna Region (Italy) and to evaluate adherence to treatment with selective serotonin receptor inhibitors or selective noradrenaline receptor inhibitors (SSRI-SNRI).

METHODS

Reimbursed prescriptions of AD were retrieved from the Emilia-Romagna Regional Health Authority Database. The overall AD consumption from the 2006-2011 period was expressed in terms of prevalence and amount of use. Adherence to treatment was assessed in a cohort of patients who received SSRI-SNRI, and was followed throughout a 6-month period from the start of each treatment episode. Adherence was considered according to three parameters: duration of treatment ≥ 120 days, prescription coverage ≥ 80 %, and gaps between prescriptions < 3 months. Determinants of non-adherent regimen, including sociodemographic and clinical variables, were identified by multivariate logistic regression by calculating adjusted Odds Ratio (adjOR) and the relevant 95 % confidence interval (95CI).

RESULTS

From 2006 to 2011, the prevalence of use of AD increased by 5 % (from 86 to 90 per 1,000 inhabitants) and the amount of antidepressant consumption increased by 20 % (from 43 to 51 defined daily dose per thousand inhabitants per day [DDD/TID]), with a 14 % rise in the intensity of drug use (from 182 to 208 DDD per patient). Out of 347,615 SSRI-SNRI treatment episodes, only 23.8 % were adherent. Comorbidity (adjOR:0.69; 95CI:0.67-0.72) and recurrence of AD treatment in the previous year (0.91; 0.89-0.92) were associated with better adherence. Moreover, patients treated with duloxetine (0.58; 0.55-0.60), escitalopram (0.64; 0.62-0.66) or sertraline (0.65; 0.64-0.67) showed better adherence in comparison with paroxetine.

CONCLUSIONS

Clinical variables resulting in improved adherence seem to identify patients with more severe disorders and who actually need a pharmacological approach, whereas differences in adherence among ADs could in part be caused by channeling and sponsorship bias. Initiatives addressed at improving cooperation between primary care and psychiatrists could decrease AD prescription for cases of sub-threshold or mild depression that easily drop out because of rapid symptom relief or side effects.

Rational use of generic psychotropic drugs

For economic reasons, the generic substitution of branded medications is common and welcome. These replacements are based on the concept of bioequivalence, which is considered equal to therapeutic equivalence. Regulatory standards for bioequivalence require the 90 % confidence intervals of group averages of pharmacokinetic measures of a generic and the original drug to overlap within ±20 %. However, therapeutic equivalence has been challenged for several psychotropic agents by retrospective studies and case reports. To evaluate the degree of bioequivalence and therapeutic equivalence of branded and generic psychotropic drugs, we performed an electronic search (from database inception until 24 May 2012 and without language restrictions) in PubMed/MEDLINE, Cochrane Library, and Web of Science. Search terms were "(generic) AND (psychotropic OR psychoactive OR antipsychotic OR antiepileptic OR antidepressant OR stimulant OR benzodiazepine)" or the respective individual substances. We included clinical studies, regardless of design, comparing branded with generic psychotropic drug formulations, identifying 35 such studies. We also included case reports/series reporting on outcomes after a switch between brand and generic psychotropics, identifying 145 clinical cases. Bioequivalence studies in healthy controls or animals, in-vitro studies, and health economics studies without medical information were excluded. An overview of the few randomized controlled studies supports that US FDA regulations assure clinically adequate drug delivery in the majority of patients switched from brand to generic. However, with a growing number of competing generic products for one substance, and growing economic pressure to substitute with the currently cheapest generic, frequent generic-generic switches, often unbeknownst to prescribing clinicians, raise concerns, particularly for antiepileptics/mood stabilizers. Generic-generic switches may vary by more than ±20 % from each other in individual patients since the pharmacokinetic properties of each generic may differ from the innovator drug in opposing directions. Ideally, therapeutic equivalence studies in addition to pharmacokinetic equivalence studies would be performed for each generic, reflecting the full variability of clinical responses due to changes of pharmacokinetic properties related to age, sex, ethnicity, genetic factors, and body mass index. This is particularly relevant, as bioequivalence studies are based on single-dose studies in healthy controls who are likely not representative of the patients who are prescribed the psychotropic medications. Additionally, individual case reports suggest potential clinical effects during brand-generic switches. Knowledge and consideration of intra-individual variations can help guide the clinical management during brand-generic or generic-generic switch periods. To optimize outcomes, clinicians need to consider that when using generic psychotropic medications, a change in the patient's clinical status can be related to psychological, interactional, physiological, and pharmacological factors that may or may not be related to the change to a generic drug. In addition, throughout all treatment periods, clinicians need to be aware of the currently dispensed product (i.e., branded or exact generic formulation), particularly when evaluating clinical changes in efficacy, tolerability, and adherence. If clinical problems occur, the first response should be an assessment of adherence and a careful dose adjustments of the generic drug rather than an immediate switch back to the originator.

A review of antidepressant therapy in primary care: current practices and future directions

Objective: To provide general practitioners with a comparison of major depressive disorder treatments received in primary care and psychiatric clinic settings, a focus on treatment outcomes related to currently prescribed antidepressants, and a review of new and emerging therapeutic strategies.

Data Sources: English-language evidence-based guidelines and peer-reviewed literature published between January 1, 2005, and December 31, 2011, were identified using PubMed, MEDLINE, and EMBASE. All searches contained the terms major depressive disorder and unipolar depression, and excluded the terms bipolar disorder/manic depressive disorder. The following search terms were also included: naturalistic study, antidepressant, relapse, recurrence, residual symptoms, response, remission, sequential medication trials, and treatment-resistant depression.

Study Selection: Meta-analyses, systematic reviews, and practice guidelines were included. Bibliographies were used to identify additional articles of interest.

Data Extraction: Abstracts and articles were screened for relevance to primary care practice. Population-based studies and those involving patients treated in primary care were used whenever possible.

Data Synthesis: Achieving remission from a major depressive episode is important to improve functional outcomes and to reduce relapse and recurrence. Despite the availability of numerous antidepressants, as many as 50% of patients require treatment modifications beyond first-line therapy. Among remitters, 90% report residual symptoms that may interfere with function. Patients treated in primary care often have chronic depression (symptom duration ≥ 24 months at presentation) and medical comorbidities. These are clinical predictors of worse outcomes and require individualized attention when treatment is initiated. Antidepressants differ in efficacy, tolerability, and side effects—factors that may affect adherence to treatment.

Conclusions: Major depressive disorder is highly prevalent in primary care and is among the most common causes of loss of disability-adjusted life-years worldwide. There are few differences in clinical profiles between depressed patients in primary care and those in specialist clinics, although differences in symptoms and comorbid conditions among individual depressed patients present a challenge for the physician providing individualized treatment. The goal of treatment is remission with good functional and psychosocial outcomes. Physicians in primary care should have expertise in working with a number of current antidepressant approaches and an awareness of new and emerging treatments.

Medication adherence and persistence in the treatment of Canadian ulcerative colitis patients: analyses with the RAMQ database

BACKGROUND

Although high non-adherence to medication has been noticed for ulcerative colitis (UC), little is known about adherence to mesalamine treatments and determinants that can predict adherence. The objective of this study was to assess adherence and persistence to mesalamine treatments and their potential determinants in mild to moderate UC patients in a real-life setting in Quebec, Canada.

METHODS

A retrospective prescription and medical claims analysis was conducted using a random sample of mesalamine users with UC. For inclusion, patients were required to initiate an oral mesalamine treatment between January 2005 and December 2009. Patients with a diagnosis of Crohn's disease were excluded. Treatment adherence (medication possession ratio [MPR]) and persistence were evaluated over a 1-year period after the index prescription using the Kaplan-Meier method with log-rank test and stepwise regression to identify potential determinants.

RESULTS

A sample of 1,681 of the new oral mesalamine users (mean age = 55.3) patients was obtained. Overall, the percentage of patients with a MPR of 80% or greater at 12 months was 27.7%, while persistence was 45.5%. Among patients treated with mesalamine delayed/extended-release tablets (Mezavant®), adherence and persistence were 40.9% and 71.9%, respectively. Predictors of high adherence included, male gender (OR=1.3; 95% confidence interval [CI]=1.1-1.6), older age (>60 years; OR=1.6; 95% CI=1.3-2.0) and current use of corticosteroids (OR=1.4; 95% CI=1.1-1.8). Predictors of high persistence included male sex (OR=1.4; 95% CI=1.1-1.7), current use of corticosteroids (OR=1.4; 95% CI=1.1-1.7) and presence of hypertension or respiratory diseases (OR=1.2; 95% CI=1.01-1.55).

CONCLUSIONS

The majority of patients with UC exhibited low adherence and persistence to mesalamine treatments. Various determinants of improved adherence and persistence were identified.

Dosing frequency and adherence in chronic psychiatric disease: systematic review and meta-analysis

BACKGROUND

The purpose of this study was to investigate the impact of dosing frequency on adherence in severe chronic psychiatric and neurological diseases.

METHODS

A systematic literature review was conducted for articles in English from medical databases. Diseases were schizophrenia, psychosis, epilepsy, bipolar disorder, and major depressive disorder.

RESULTS

Of 1420 abstracts screened, 12 studies were included. Adherence measures included Medication Event Monitoring System (MEMS(®)), medication possession ratio, medication persistence, and refill adherence. Three schizophrenia and one epilepsy study used MEMS, and all showed a trend towards higher adherence rates with less frequent dosing regimens. Three depression and one schizophrenia study used the medication possession ratio; the pooled odds ratio of being adherent was 89% higher (ie, 1.89, 95% credibility limits 1.71-2.09) on once-daily versus twice-daily dosing. Two studies in depression and one in all bupropion patients assessed medication persistence and refill adherence. The pooled odds ratio for the two depression studies using medication persistence was 2.10 (95% credibility limits 1.86-2.37) for once-daily versus twice-daily dosing. For refill adherence after 9 months, 65%-75% of patients on once-daily versus 56% on twice-daily dosing had at least one refill. In all but one of the studies using other measures of adherence, adherence rates were higher with once-daily dosing compared with more frequent dosing regimens. No relevant studies were identified for bipolar disorder or psychosis.

CONCLUSION

Differences in study design and adherence measures used across the studies were too large to allow pooling of all results. Despite these differences, there was a consistent trend of better adherence with less frequent dosing.

Factors associated with antidepressant medication adherence and adherence-enhancement programmes: a systematic literature review

Medication adherence is critical to the efficacy of available treatment for depression in primary care settings. This review identifies factors associated with adherence and what is known about the effectiveness of adherence-enhancement programmes. A comprehensive systematic review of English language publications from January 2002 to October 2011 was conducted using the following databases: PUBMED/MEDLINE, PsycINFO and the Cochrane database. Twenty-one studies met the inclusion criteria for adherence-enhancement evaluations. Eleven of the studies evaluated demonstrated significantly positive effects on adherence; the remaining 10 reported mixed or no effects. Similar to previous literature reviews, factors shown to be associated with adherence were multifactorial and in this analysis were grouped as patient, condition and comorbidities, therapy or treatment, patient-provider relationship and healthcare system level. Adherence improved most notably in studies that included sustainable system and patient-targeted changes. Evaluating adherence-enhancement interventions is key to promoting successful approaches; however, a number of gaps exist between intervention and implementation: (1) the cost in resources and time to implement and sustain these programmes is unknown, (2) specific details about which subgroups of patients are best helped with such programmes is not clear, and (3) what specific processes or content are critical to programme success is still to be identified. There are sufficient data supporting the substantial need for planning and implementing adherence interventions despite reported mixed results. Primary care providers are often positioned to impact patients' adherence; however, practice constraints can limit their implementation.