Economic Impact of Therapeutic Substitution of a Brand Selective Serotonin Reuptake Inhibitor with an Alternative Generic Selective Serotonin Reuptake Inhibitor in Patients with Major Depressive Disorder

Challenges for switching central nervous system and psychiatric medication products: A review of the literature

BACKGROUND

Switching between versions of medication products happens commonly despite challenges in achieving bioequivalence and therapeutic equivalence. Central nervous system and psychiatric drugs, especially those that are technically demanding to manufacture and have complex pharmacokinetic properties, such as long-acting injectables (LAIs), pose particular challenges to bioequivalence and safe and efficacious drug switching.

AIMS

To assess whether drugs deemed "bioequivalent" are truly interchangeable in drug switching.

METHODS

We assessed the published literature from January 2017 through June 2023 on PubMed using the MeSH terms "drugs, generic" OR "equivalency, generic" combined with terms for different psychiatric drug classes.

RESULTS

While most of the published studies returned in the search found that switching drug products was safe and clinically comparable, data on most drug classes other than those primarily indicated in the treatment of seizure disorder were sparse. Some studies also provided evidence that real-world outcomes such as adherence and hospitalizations may also be affected by switching. In addition, a review of bioequivalence testing guidance showed inconsistency across agencies and a lack of product-specific guidance from Health Canada, which raises questions about potential claims of bioequivalence for more complex products such as LAIs.

CONCLUSIONS

Overall, given the difficulty in treating mental health disorders, prescribers should be cautious when switching products and formulations in a patient who has been stabilized on a drug.

Brand-Name Antidepressants Outperform Their Generic Counterparts in Preventing Hospitalization for Depression: The Real-World Evidence from Taiwan

BACKGROUND

Generic antidepressants are approved on the market based on evidence of bioequivalence to their brand-name versions. We aimed to assess whether generic antidepressants exert equal effectiveness as their brand-name counterparts for treating patients with depressive disorders.

METHODS

In a nationwide, population-based cohort in Taiwan from 1997 through 2013, patients with a diagnosis of a depressive disorder aged between 18 and 65 years who were new users of antidepressant drugs were classified into either the brand-name group or the generic group. All patients were followed up until medication discontinuation or the end of the study period. We assessed the risk for hospitalization as a primary outcome and augmentation therapy, daily dose, medication discontinuation, or switching to another antidepressant as secondary outcomes.

RESULTS

A total of 277 651 brand-name users (35.8% male; mean age: 41.2 years) and 270 583 generic users (35.8% male; mean age: 41.0 years) were divided into 10 different antidepressant groups (fluoxetine, sertraline, paroxetine, escitalopram, citalopram, venlafaxine, mirtazapine, moclobemide, imipramine, and bupropion). We found that patients treated with the generic form of sertraline, paroxetine, escitalopram, venlafaxine, mirtazapine, and bupropion demonstrated significantly higher risks of psychiatric hospitalization (adjusted hazard ratios ranged from 1.20-2.34), compared to their brand-name counterparts. The differences between brand-name antidepressants and their generic counterparts in secondary outcomes varied across different drugs.

CONCLUSIONS

Compared to most generic antidepressants, brand-name drugs exhibited more protective effects on psychiatric hospitalization for depressive patients. These findings could serve as an important reference for clinicians when encountering patients with depressive disorder.

The impact of non-medical switching among ambulatory patients: an updated systematic literature review

Background: Non-medical switching (NMS) is defined as switching to a clinically similar but chemically distinct medication for reasons apart from lack of effectiveness, tolerability or adherence. Objective: To update a prior systematic review evaluating the impact of NMS on outcomes. Data sources: An updated search through 10/1/2018 in Medline and Web of Science was performed. Study selection: We included studies evaluating ≥25 patients and measuring the impact of NMS of drugs on ≥1 endpoint. Data extraction: The direction of association between NMS and endpoints was classified as negative, positive or neutral. Data synthesis: Thirty-eight studies contributed 154 endpoints. The direction of association was negative (n = 48; 31.2%) or neutral (n = 91; 59.1%) more often than it was positive (n = 15; 9.7%). Stratified by endpoint type, NMS was associated with a negative impact on clinical, economic, health-care utilization and medication-taking behavior in 26.9%,41.7%,30.3% and 75.0% of cases; with a positive effect seen in 3.0% (resource utilization) to 14.0% (clinical) of endpoints. Of the 92 endpoints from studies performed by the entity dictating the NMS, 88.0%were neutral or positive; whereas, only 40.3%of endpoints from studies conducted separately from the interested entity were neutral or positive. Conclusions: NMS was commonly associated with negative or neutral endpoints and was seldom associated with positive ones.

Switching medication products during the treatment of psychiatric illness

BACKGROUND

The common practice of switching between branded (reference) medications and their corresponding generic products, between generic products, or even from a generic product to a branded medication during the treatment of central nervous system (CNS) disorders may compromise efficacy and/or tolerability.

METHODS

We assessed the published literature from March 1, 2010 through June 30, 2017 via PubMed using the MeSH term 'generics, drugs' alone and in combination with class-specific terms (e.g., 'anticonvulsants', 'mood stabilisers'), for studies detailing outcomes following product switches.

RESULTS

Although some studies comparing the initiation of reference versus generic drugs suggest equivalence between products, several studies detailing a switch between reference and generic products describe reductions in efficacy, reduced medication adherence and persistence, and increased overall health care resource utilization and costs associated with generic substitution.

CONCLUSION

When product switches are considered, they should only proceed with the full knowledge of both patient and provider.

Medication changes after switching from CONCERTA® brand methylphenidate HCl to a generic long-acting formulation: A retrospective database study

Background

Observational studies of switching from branded to generic formulations of the same drug substance often lack appropriate comparators for the subjects who switched. Three generic formulations were deemed equivalent to Concerta: an authorized generic (AG) identical except for external packaging, and two other generics (EG).

Objective

Compare the incidence of a combined endpoint (switching back to Concerta, changing the use of immediate release methylphenidate (MPH), stopping all long-acting methylphenidate, or starting a new medication) among people switched from Concerta to the AG versus the EG.

Methods

Cohort study from the Truven CCAE database of people aged 6 to 65 diagnosed with ADHD, treated with Concerta, and switched to the EG or to the AG formulation.

Results

In the EG arm 24.6% and in the AG arm 19.7% of subjects switched back to Concerta. The proportion of subjects meeting the combined endpoint was 39.5% in the EG arm, 32.9% in the AG arm, a crude risk ratio of 1.20 (95% CI 0.94, 1.54). After adjustment by propensity score stratification, the adjusted odds ratio (OR) was 1.23 (95% CI 0.90, 1.70). In an unplanned analysis using a different method of adjustment, the adjusted OR was 1.00 (95% CI 0.69, 1.44).

Discussion

This study did not detect a difference between the proportion of people who met the study endpoint in the two study arms, i.e. between those who switched to a generic formulation that was identical to Concerta except for external packaging and those who switched to the comparison generics. The high incidence of the combined endpoint in the AG arm demonstrates the need for an appropriate comparator in studies of this type.

Trial registration

ClinicalTrials.gov NCT02730572

Pharmacare: Are we getting the right medicines?

Canada is the only country in the world with a national healthcare plan that does not include drug coverage. Coverage of necessary medications is a patchwork of inconsistent programs that does not always serve the very individuals it was created to help-those patients who need prescribed medicines. Our system needs radical, intuitive changes.

Impact of non-medical switching on clinical and economic outcomes, resource utilization and medication-taking behavior: a systematic literature review

OBJECTIVE

To evaluate current knowledge of the impact of non-medical switching on clinical and economic outcomes, resource utilization and medication-taking behavior.

METHODS

The literature was searched (Medline and Web of Science, January 2000-November 2015) to identify United States' studies evaluating ≥25 patients and measuring the impact of non-medical switching of drugs (switching to a chemically distinct but similar medication for reasons other than lack of clinical efficacy/response, side effects or poor adherence) on ≥1 clinical, economic, resource utilization or medication-taking behavior outcome. The direction of association between non-medical switching and outcomes was classified as negative or positive if a statistically significant worsening or improvement was reported, or neutral if no significant difference was observed.

RESULTS

Twenty-nine studies contributed 96 outcomes (60.4% clinical; 21.9% resource utilization; 13.5% economic; 4.2% medication-taking behavior) within six disease categories (cardio-metabolic, immune-mediated, acid suppression, psychiatric, hormone replacement therapy and pain). The direction of association was more frequently negative (33.3%) or neutral (55.2%) than it was positive (11.5%). Stratified by outcome type, non-medical switching was negatively associated with clinical, economic, healthcare utilization and medication-taking behavior outcomes in 20.7%, 69.2%, 38.1% and 75.0% of cases, respectively; and positively in only 4.8%-17.2% of outcomes subgroups. Of 32 outcomes in patients demonstrating stable/well controlled disease, 68.8% and 31.3% had a negative and neutral direction of association. In patients without demonstrated disease stability, outcomes were negatively, neutrally and positively impacted by non-medical switching in 15.6%, 67.2% and 17.2% of 64 outcomes.

LIMITATIONS

Our inability to evaluate specific disease state categories and studies/outcomes received equal weight regardless of sample size or magnitude of effect.

CONCLUSIONS

Non-medical switching was more often associated with negative or neutral effects than positive effects on an array of important outcomes. Among patients with stable/well controlled disease, non-medical switching was associated with mostly negative effects.

An Evaluation of Health Service Impacts Consequent to Switching from Brand to Generic Venlafaxine in New Zealand under Conditions of Price Neutrality

OBJECTIVE

To study the health impact on adult New Zealand patients who switch from originator brand to generic venlafaxine.

METHODS

The national pharmacy database was used to select patients using venlafaxine for at least 6 months. Switchers and nonswitchers were identified, and switch behavior was compared for a 12-month follow-up period. Change in health service use following switching was also compared between switchers and nonswitchers including use of the emergency department, hospital, and specialist outpatient services over the same period.

RESULTS

Approximately 12% of all originator brand users switched to generic venlafaxine, at least half of whom continued to use the generic throughout the follow-up period to August 1, 2012. Almost 60% of new users of the generic venlafaxine, however, switched to using the originator brand. Aside from a slight reduction in the use of outpatient services among switchers, there were no significant differences in health services use between switchers and nonswitchers for either existing or new venlafaxine users.

CONCLUSIONS

Although both products remain fully subsidized and available, there is little incentive for prescribers, pharmacists, or patients to switch to the less expensive generic brand. If savings to the national New Zealand budget are to be realized, additional policy measures should be implemented to minimize incentives for multiple and reverse switching, and prescribers, as key opinion leaders, could take the lead in promoting generics to their patients.

Health resource use and costs of vilazodone and other selective serotonin re-uptake inhibitors in treating major depressive disorder

OBJECTIVE

Selective serotonin re-uptake inhibitors (SSRIs) are widely prescribed antidepressants. This claims database study compared healthcare resource use and costs among patients with major depressive disorder (MDD) treated with vilazodone vs other SSRIs.

METHODS

Adults with an MDD diagnosis and ≥ 1 prescription fill for vilazodone, citalopram, escitalopram, fluoxetine, paroxetine, or sertraline were identified from administrative claims data (2010-2012). Patients who concomitantly used adjunctive medication, either a second-generation antidepressant or antipsychotic, were excluded. All-cause and MDD-related healthcare resource use and costs (in 2012 USD) were compared between patients treated with vilazodone vs other SSRIs over a 6-month follow-up period using unadjusted and multivariable analyses.

RESULTS

The study cohort included 49 861 patients (mean age = 44.0 years; 70% female). Compared with the vilazodone cohort (n = 3527), patients in the citalopram (n = 12 187), escitalopram (n = 8275), fluoxetine (n = 10 142), paroxetine (n = 3146), and sertraline (n = 12 584) cohorts had significantly more all-cause inpatient hospital visits, longer hospital stays and more frequent emergency department visits, following the index date, after adjusting for baseline characteristics. All-cause medical service costs (inpatient + outpatient + emergency department visits) were significantly higher across all other SSRI cohorts vs vilazodone by $758-$1165 (p < 0.05). Similarly, all-cause total costs, were significantly or numerically (non-significantly) higher across all SSRI cohorts vs vilazodone by $351-$780.

LIMITATIONS

The was no clinical measurement of disease severity, partial coverage of the Medicare-eligible population, and short follow-up.

CONCLUSION

MDD treatment with vilazodone was associated with significantly lower rates of inpatient and emergency services, and with significantly lower all-cause medical service costs and numerically (non-significantly) lower total costs to payers than with the other SSRIs included in this study.

Efficacy and safety of generic escitalopram (Lexacure(®)) in patients with major depressive disorder: a 6-week multicenter, randomized, rater-blinded, escitalopram-comparative, non-inferiority study

OBJECTIVES

The primary aim of this non-inferiority study was to investigate the clinical effectiveness and safety of generic escitalopram (Lexacure(®)) versus branded escitalopram (Lexapro(®)) for patients with major depressive disorder (MDD).

METHODS

The present study included 158 patients, who were randomized (1:1) to receive a flexible dose of generic escitalopram (n=78) or branded escitalopram (n=80) over a 6-week single-blind treatment period. The clinical benefits in the two groups were evaluated using the Montgomery-Åsberg Depression Rating Scale (MADRS), the 17-item Hamilton Depression Rating Scale (HDRS), the Clinical Global Impressions-Severity scale (CGI-S), and the Clinical Global Impressions-Improvement scale (CGI-I) at baseline, week 1, week 2, week 4, and week 6. The frequency of adverse events (AEs) was also assessed to determine safety at each follow-up visit.

RESULTS

During the 6-week study period, 30 patients (38.5%) from the generic escitalopram group and 28 patients (30.0%) from the branded escitalopram group dropped out of the study (P=0.727). The MADRS, HDRS, CGI-S, and CGI-I scores significantly decreased in both groups, and there were no significant differences between the groups. At week 6, 28 patients (57.1%) in the generic escitalopram group and 35 patients (67.3%) in the branded escitalopram group had responded to treatment (as indicated by a ≥50% decrease from the baseline MADRS score; P=0.126), and the remission rates (MADRS score: ≤10) were 42.9% (n=21) in generic escitalopram group and 53.8% (n=28) in the branded escitalopram group (P=0.135). The most frequently reported AEs were nausea (17.9%), sleepiness/somnolence (7.7%), weight gain (3.8%), and dry mouth (2.6%) in the generic escitalopram group and nausea (20.0%), sleepiness/somnolence (3.8%), weight gain (2.5%), and dry mouth (2.5%) in the branded escitalopram group.

CONCLUSION

The present non-inferiority study demonstrated that generic escitalopram is a safe and an effective initial treatment for patients with MDD and may also be considered as an additional therapeutic option for this population.

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.

Patented drug extension strategies on healthcare spending: a cost-evaluation analysis

BACKGROUND

Drug manufacturers have developed "evergreening" strategies to compete with generic medication after patent termination. These include marketing of slightly modified follow-on drugs. We aimed to estimate the financial impact of these drugs on overall healthcare costs and also to examine the impact of listing these drugs in hospital restrictive drug formularies (RDFs) on the healthcare system as a whole ("spillover effect").

METHODS AND FINDINGS

We used hospital and community pharmacy invoice office data in the Swiss canton of Geneva to calculate utilisation of eight follow-on drugs in defined daily doses between 2000 and 2008. "Extra costs" were calculated for three different scenarios assuming replacement with the corresponding generic equivalent for prescriptions of (1) all brand (i.e., initially patented) drugs, (2) all follow-on drugs, or (3) brand and follow-on drugs. To examine the financial spillover effect we calculated a monthly follow-on drug market share in defined daily doses for medications prescribed by hospital physicians but dispensed in community pharmacies, in comparison to drugs prescribed by non-hospital physicians in the community. Estimated "extra costs" over the study period were €15.9 (95% CI 15.5; 16.2) million for scenario 1, €14.4 (95% CI 14.1; 14.7) million for scenario 2, and €30.3 (95% CI 29.8; 30.8) million for scenario 3. The impact of strictly switching all patients using proton-pump inhibitors to esomeprazole at admission resulted in a spillover "extra cost" of €330,300 (95% CI 276,100; 383,800), whereas strictly switching to generic cetirizine resulted in savings of €7,700 (95% CI 4,100; 11,100). Overall we estimated that the RDF resulted in "extra costs" of €503,600 (95% CI 444,500; 563,100).

CONCLUSIONS

Evergreening strategies have been successful in maintaining market share in Geneva, offsetting competition by generics and cost containment policies. Hospitals may be contributing to increased overall healthcare costs by listing follow-on drugs in their RDF. Therefore, healthcare providers and policy makers should be aware of the impact of evergreening strategies.