Switching from brand-name to generic psychotropic medications: a literature review

Pharmacoeconomic implications of preference toward reference- versus generic-brand antidepressants in primary care

BACKGROUND

The prevalence of depression is gradually increasing worldwide with an increasing utilization of antidepressants. Nevertheless, despite their lower costs, generic-brand antidepressants were reported to be less prescribed. We aimed to examine the costs of reference- versus generic-brand antidepressant prescriptions in primary care practice.

METHODS

This cross-sectional study included electronic prescriptions for adult patients that contained antidepressants (World Health Organization's Anatomical Therapeutic Chemical (ATC) code: N06A), which were generated by a systematically selected sample of primary care doctors (n = 1431) in Istanbul in 2016. We examined the drug groups preferred, the reference- versus generic-brand status, and pharmacotherapy costs.

FINDINGS

The majority of the prescriptions were prescribed for women (71.8%), and the average age of the patients was 53.6 ± 16.2 years. In prescriptions with a depression-related indication (n = 40 497), the mean number and cost of drugs were 1.5 ± 1.0 and 22.7 ± 26.4 United States Dollar ($) per prescription, respectively. In these prescriptions, the mean number and cost of antidepressants per encounter were 1.1 ± 0.2 and $17.0 ± 13.2, respectively. Reference-brand antidepressants were preferred in 58.2% of depression-related prescriptions, where the mean cost per prescription was $18.3 ± 12.4. The mean cost per prescription of the generics, which constituted 41.8% of the antidepressants in prescriptions, was $15.1 ± 11.4. We found that if the generic version with the lowest cost was prescribed instead of the reference-brand, the mean cost per prescription would be $12.9 ± 11.2.

CONCLUSIONS

Our study highlighted the substantial pharmacoeconomic impact of generic-brand antidepressant prescribing, whose preference over reference-brands could reduce the cost of antidepressant medication treatment by 17.5% in primary care, which could be approximately doubled if the cheapest generic antidepressant had been prescribed.

Generic orphan drug substitution: a critical analysis of global practices and Saudi Arabia's perspective

In an era of cost pressure, substituting generic drugs represents one of the main cost-containment strategies of healthcare systems. Despite the obvious financial benefits, in a minority of cases, substitution may require caution or even be contraindicated. In most jurisdictions, to obtain approval, the bioequivalence of generic products with the brand-name equivalent needs to be shown via bioavailability studies in healthy subjects. Rare diseases, defined as medical conditions with a low prevalence, are a group of heterogenous diseases that are typically severe, disabling, progressive, degenerative, and life-threatening or chronically debilitating, and disproportionally affect the very young and elderly. Despite these unique features of rare diseases, generic bioequivalence studies are typically carried out with single doses and exclude children or the elderly. Furthermore, the excipients and manufacturing processes for generic/biosimilar products can differ from the brand products which may affect the shelf-life of the product, its appearance, smell, taste, bioavailability, safety and potency. This may result in approval of generics/biosimilars which are not bioequivalent/comparable in their target population or that meet bioequivalence but not therapeutic equivalence criteria. Another concern relates to the interchangeability of generics and biosimilars which cannot be guaranteed due to the phenomenon of biocreep. This review summarizes potential concerns with generic substitution of orphan drugs and discusses potentially problematic cases including narrow therapeutic index drugs or critical conditions where therapeutic failure could lead to serious complications or even death. Finally, we put forward the need for refining regulatory frameworks, with emphasis on Saudi Arabia, for generic substitution and recent efforts toward this direction.

Differential effects of healthcare worker burnout on psychotropic medication use and misuse by occupational level

PURPOSE

Burnout has been well examined among physicians and other high-wage, high-autonomy healthcare positions. However, lower-wage healthcare workers with less workplace autonomy (e.g., medical assistants, nurses' aides) represent a substantial proportion of the workforce, but remain understudied. We aimed to examine the effects of burnout on psychotropic medication use and misuse and whether these effects differed by occupational level.

METHODS

In March 2022, we collected data from a diverse sample of US healthcare workers (N = 200) and examined the cross-sectional relationship between burnout and changes in prescribed psychotropic medication (i.e., starting, stopping, and/or having a change in the dose/frequency) during the COVID-19 pandemic. We also separately examined the relationship between burnout and psychotropic medication misuse (i.e., without a prescription, in greater amounts, more often, longer than prescribed, and/or for a reason other than prescribed). We stratified models by occupational level (prescribers/healthcare administrators vs. other healthcare workers).

RESULTS

Greater burnout was associated with higher odds of changes in prescribed psychotropic medication among prescribers/healthcare administrators (aOR = 1.23, 95% CI 1.01, 1.48), but not among other healthcare workers (aOR = 1.04, 95% CI 0.98, 1.10). Greater burnout was not associated with psychotropic medication misuse among prescribers/healthcare administrators (aOR = 0.96, 95% CI 0.82, 1.12) but was associated with increased odds of psychotropic medication misuse among other healthcare workers (aOR = 1.07, 95% CI 1.01, 1.14).

CONCLUSIONS

Potential disparities in help-seeking and healthcare access might manifest in non-medical use of prescription drugs among some healthcare workers, which has implications for worker safety and well-being.

Comparative Study of the Efficacy and Side Effects of Brand-Name and Generic Clozapine for Long-Term Maintenance Treatment Among Korean Patients With Schizophrenia: A Retrospective Naturalistic Mirror-Image Study

OBJECTIVE

Clozapine is considered the most reliable drug for treatment-resistant schizophrenia. In 2014, a generic formulation of clozapine (Clzapine) was introduced in Korea. This study was performed to provide clinical information regarding the use of clozapine and to compare efficacy and tolerability when converting from the brand-name formulation (Clozaril) to the generic formulation during longterm maintenance treatment among Korean patients with schizophrenia.

METHODS

This mirror-image study retrospectively investigated the electronic medical records of patients who had switched from Clozaril to Clzapine with a ≥1-year duration for each formulation. Clinical data were collected, including information regarding clozapine use, psychiatric hospitalization, co-medications, and blood test findings. Data before and after the switch were compared using paired t-tests.

RESULTS

Among 332 patients, the mean 1-year dosages were 233.32±149.35 mg/day for Clozaril and 217.36±136.66 mg/day for Clzapine. The mean clozapine concentration-to-dose ratios were similar before and after the switch (Clozaril, 1.33±0.68; Clzapine, 1.26±0.80). Switching from Clozaril to Clzapine resulted in no significant differences in the hospitalization rate, hospitalization duration, or laboratory findings (liver function parameters, serum cholesterol level, and serum glucose level). Equivalent doses of co-prescribed antidepressants were decreased, but concomitant medications otherwise showed no significant differences.

CONCLUSION

Clinical efficacy and tolerability appear comparable when switching to Clzapine during clozapine maintenance treatment. This study offers descriptive real-world clinical insights into clozapine maintenance treatment in Korea, thereby providing patients with more treatment options and contributing to the development of maintenance guidelines tailored to the Korean population.

Quality control concerns in relation to lamotrigine and their impact

OBJECTIVE

To pursue explanations for compromised efficacy and induction of side-effects in some generic brands of lamotrigine distributed in Australia.

METHOD

Bioassays of the non-generic and five generic lamotrigine tablets were undertaken (also after exposure to heat and cold), as well as assays of two generic drugs generating concerning side-effects in two patients, while enquiries were made of manufacturing companies.

RESULTS

Mass spectrometry of the six tested products showed comparable properties and no compromising when those tablets were heated and cooled, while analyses of the products taken by the two patients reporting significant side-effects showed an increase in the peak area lamotrigine concentration.

CONCLUSIONS

We failed to identify any intrinsically compromised product in our comparison analyses of the six preparations. We consider alternate explanations for an issue leading to widespread international reporting of distinct side-effects and deaths following brand switching, with analyses of the two problematic preparations supporting a 'faulty' batch explanation.

Shortages of medicines in a psychiatric hospital in Cyprus

Background

The incidence of drug shortages has surged in recent years and it poses a major threat to public health worldwide. It can also downgrade the quality of care provided to patients. Data concerning shortages pertinent to mental health care are scarce, while treatment continuity is vital to avert disease recurrence and deterioration of patients’ mental health.

Objective

The scope of this study is to elucidate the attitudes and perceptions of mental health professionals regarding drug shortages in Cyprus in a tertiary health institute, through a specially designed questionnaire.

Results

The most frequently reported effects of psychiatric drug shortages were the impaired efficacy of the alternative therapeutic regimen, re-admission of patients, delays in care provision and increased frequency of adverse events. Concerning the loss of working hours in managing drug shortages, the majority responded that they dedicate 1 to 5 working hours to this per week. Informing the patient about alternative medication and the ongoing shortages were the first strategies to minimise the effects of shortages, as attested by 74% and 72% of responders, respectively. The proposed solutions for drug shortages included thorough investigation of the root causes, the elaboration of an e-based database, drawing up a national annual report and assuming legal responsibility of pharmaceutical companies. Drug shortages constitute an important burden in the field of mental health care in Cyprus. Given the serious impact of the problem and the externalities of mental health disorders, appropriate measures must be swiftly taken to ensure timely and effective administration of the appropriate therapeutic regimen.

The problem of choice: original drug or generic? Emphasis on rosuvastatin

An increase in the life expectancy of the population and the number of polymorbid patients with a combination of two or more diseases in different age categories, including among young people, has led to a significant increase in the cost of medical care in the field of public health. The transition from original drugs to generic ones has become a common measure to contain these costs. While this is an important goal for healthcare systems around the world, the impact of this practice on patient outcomes needs to be carefully considered. In some cases, generics may represent a suitable alternative to branded products, but this is not always the case. In particular, studies have shown that changing the drug can negatively affect not only patients' adherence to treatment, but also clinical outcomes, and a subsequent increase in the total cost of treatment, therefore, the use of generics in clinical practice still causes caution and concerns on the part of both the doctor and the patient. Due to the high prevalence of dyslipidemia and hypercholesterolemia both worldwide and in Russia, in this review the problem of choosing an original drug or generic is described by the example of such a hypolipidemic agent as rosuvastatin. According to numerous studies, rosuvastatin is one of the most potent and widely prescribed statins. Considering that most of the clinically significant effects of this drug are demonstrated in relation to its original form, the review emphasizes the importance of prescribing the original drug rosuvastatin in routine clinical practice.

Therapeutic Basis of Generic Substitution of Antiseizure Medications

More than thirty antiseizure medications (ASMs) are available for treating epilepsy. ASMs differ in their potency and efficacy in controlling seizures by acting on diverse targets in the brain, often with variable pharmacokinetics. Moreover, nearly 30% of people with epilepsy have drug-resistant or intractable seizures. Generic substitution of ASMs is a complex issue. It is thought that frequent generic substitution in people with epilepsy may cause problems because the U.S. Food and Drug Administration (FDA) rules allow too much variability across products. The standard bioequivalence range (80% to 125%) appears too broad for many ASMs, especially those exhibiting little separation between therapeutic and toxic levels. Hence, sub-therapeutic concentration may lead to therapeutic failure with seizure recurrence, which could be life threatening. A supra-therapeutic level could result in adverse effects or compliance issues. There are reported issues with generic substitutions of phenytoin, topiramate, levetiracetam, carbamazepine, and lamotrigine. There is discussion in the epilepsy community about additional guidelines, including designation of generic ASMs as Narrow Therapeutic Index (NTI) drugs and how patient education plays a role in generic substitution. Overall, based on the published evidence on specific generic ASMs, FDA bioequivalence standards are not the cause of problems with generic ASM substitution. Rather, it is imperative that physicians and pharmacists provide adequate patient education on what to expect when switching to generic ASMs, including changes in medication shape and color. Another suggestion would be to consider that all ASMs be considered for inclusion in NTI class to prevent the clinical outcome issues associated with generic ASM switching. SIGNIFICANCE STATEMENT: There are critical aspects to consider when switching from a brand name antiseizure medication (ASM) when a generic becomes available or switching between generics. Generic ASMs are interchanged with little consideration of differences in therapeutic equivalence and other clinical factors. This article describes key issues on generic substitution of ASMs and highlights critical pharmacotherapeutic issues associated with generic ASMs.

Risk of hospitalized depression and intentional self-harm with brand and authorized generic sertraline

BACKGROUND

Recent suggestions of therapeutic inequivalence of brand and generic sertraline have raised concerns about disproportionately higher adverse events among generic users.

OBJECTIVE

To assess the impact of confounding in a comparison of the risks of worsening depression and intentional self-harm (ISH) between users of brand name sertraline and its pharmaceutically equivalent authorized generic (AG).

METHODS

Using a retrospective new-user cohort design, we identified patients with a diagnosis code for depression aged ≥12 years who were continuously enrolled in a Sentinel Data Partner health plan for ≥180 days before their first sertraline dispensing between June 30, 2006 and September 30, 2015. New use was defined as no evidence of sertraline dispensing in the 180 days before index date. We matched each brand name user to up to 10 AG users using propensity scores (PS) and conducted case-centered logistic regression to assess the risks of hospitalized depression and ISH.

RESULTS

Before PS matching, brand name users were significantly less likely to be hospitalized for depression [Hazard Ratio (HR) = 0.70 (95% confidence interval (CI): 0.53-0.94)]. However, in the matched analysis, we observed no statistical difference between brand and AG users [HR = 0.84 (95% CI: 0.59-1.21)]. The risk of ISH did not significantly differ between the exposure groups in unmatched (HR = 0.99 (95% CI: 0.60-1.62) and matched analyses [HR = 0.91 (95% CI: 0.49-1.70).

CONCLUSION

In depressed patients receiving brand versus AG sertraline, patient characteristics confounded the association with hospitalization. Baseline differences were ameliorated by PS matching resulting in no statistical difference between brand and AG sertraline users.

Harmonization of summaries of product characteristics (SmPCs) of drugs with the same active ingredients: an evaluation of SmPCs of the most frequently prescribed active substances

Purpose

In aut-idem or generic substitution, discrepancies between summaries of product characteristics (SmPCs) referring to the same active substance (AS) may cause difficulties regarding informed consent and medical liability. The qualitative and quantitative characteristics of such discrepancies are insufficiently studied, impeding harmonization of same-substance SmPCs and compromising safe drug treatment.

Methods

SmPCs of the one hundred most frequently prescribed ASs in Germany were analyzed for discrepancies in the presentation of indications (Inds) and contraindications (CInds). Inclusion and exclusion criteria of drugs/SmPCs were chosen according to the standards of the aut-idem substitution in Germany.

Results

According to the study protocol, we identified 1486 drugs, of which 1426 SmPCs could be obtained. 41% respectively 65% of the ASs had same-substance SmPCs that differed from the respective reference SmPC in the number of listed Inds respectively CInds. The number of listed Inds/CInds varied considerably between same-substance SmPCs with maximum ranges in Inds of 7 in amoxicillin, and in CInds of 11 in lisinopril. Many ASs had large proportions (> 50%) of associated same-substance SmPCs that differed from the respective reference SmPC. A considerable proportion of ASs had same-substance SmPCs with formal and content-related differences other than the discrepancy in the number of Inds/CInds.

Conclusion

This evaluation of same-substance SmPCs shows a clear lack of harmonization of same-substance SmPCs. Considering that generic substitution has become the rule and that physicians usually do not know which drug the patient receives in the pharmacy, these discrepancies raise several questions, that require a separate legal evaluation.

Evaluation of Switch-to-Brand Rates as a Potential Signal for Therapeutic Equivalency of Generic Antidepressants: A Real-World Retrospective Cohort Study

Negative clinical outcomes after switching from brand to generic antidepressants have raised concerns regarding therapeutic equivalency. This research aims to estimate the prevalence of switching and to identify predictors for generic to brand switching for various antidepressants. This retrospective cohort study utilized data from a 10% random sample of enrollees in the IQVIA PharMetrics Plus claims database from 2007-2015. The base cohort consisted of commercially insured patients who were prescribed escitalopram, duloxetine, or venlafaxine extended release (ER) anytime from the year prior to the generic launch through December 2014. The primary outcome was defined as a switch from generic to a brand within 14 days of sustained generic use in a 1-year follow-up period. Adjusted logistic regression and generalized estimating equations for repeated measures estimated the drug specific and overall odds of switch-to-brand among brand initiators relative to generic initiators, respectively. A total of 102,831 unique patients across 3 drug products contributed to the final analytic sample. The overall prevalence of switch from generic to brand was 0.74%. Across all three antidepressants, brands initiators were more likely to experience a switch-to-brand: escitalopram (odds ratio (OR): 14.41, 95% confidence interval (CI): 11.14-18.64), duloxetine (OR: 8.08, 95% CI: 4.85-13.41) and venlafaxine ER (OR: 16.46, 95% CI: 11.56-23.46). The pooled odds of a switch-to-brand in brand vs. generic initiators was 13.77 (95% CI: 11.35-16.71). This study suggests a low overall switch-to-brand prevalence and may support therapeutic equivalence between brand and generic antidepressants. Initiating with a brand product was the strongest predictor for switching back to brand and suggests that patient experience may play a role in drug utilization.

Patient factors associated with oral generic olanzapine initiation and substitution among Medicaid beneficiaries: a new user cohort study

OBJECTIVE

Generic drugs typically are less expensive than branded products; however, several factors can limit generic drug utilization. This study assesses the associations of patient factors with generic olanzapine initiation and substitution.

METHODS

A retrospective new user cohort study was conducted using the 2011-2012 Medicaid administrative claims data. Beneficiaries continuously enrolled during the 6 month washout period prior to their initial oral brand or generic olanzapine prescription were included and followed up to 12 months. Among brand olanzapine new users, time to generic substitution and competing risk outcomes was estimated using the Fine-Gray cumulative incidence function. Patient demographic and health service utilization factors were assessed in the multivariate cause-specific hazards model.

RESULTS

Among olanzapine new users, 70.7% patients initiated generic treatment. Beneficiaries aged ≥21, and living in the Midwest and West regions were more likely to initiate generic olanzapine. Among brand new users, 28.2% switched to generic olanzapine, 23.6% switched to an alternative atypical antipsychotic treatment and 38.0% discontinued within 12 months. Beneficiaries who resided in urban areas (adjusted hazard ratio [AHR) = 0.53, 95% CI = 0.37-0.75) and had prior hospitalizations (AHR = 0.85, 95% CI = 0.75-0.96) had lower rates of generic substitution, whereas those with emergency department (ED) visits (AHR = 1.06, 95% CI = 1.02-1.10) had a higher rate of generic substitution. In addition, beneficiaries in different age subgroups also had different rates of generic substitution in different regions.

CONCLUSION

Medicaid beneficiaries' age, geographic region, prior hospitalization and ED utilization were associated with generic olanzapine initiation and substitution. Tailored educational outreach targeting these patient subgroups might improve generic olanzapine utilization.

Comparison of the efficacy of Tegatard and Tegretol as a monotherapy in patients with focal seizure with or without secondary generalization

BACKGROUND

Carbamazepine is a first line treatment for focal epilepsy. Tegretol and Tegatard are two trade name of Carbamazepine. Tegretol is produced by Novartis Pharmaceutical Company, Switzerland. Recently, Raha pharmaceutical Company in Iran has produced CBZ which trade named is Tegatard. Extended usage of Tegatard instead of Tegretol has economic benefits for Iranian families. In this clinical trial, we aimed to compare therapeutic efficacy and safety of Tegretol and Tegatard in patients suffering from focal seizures with or without secondary generalization.

METHODS

200 patients with provoked or non-provoked focal seizure with or without secondary generalization were screened and 180 patients were fulfilled the criteria to enter this double blinded clinical trial study. Patients were divided into two groups, the first group (A) received Tegretol and the second group (B) Tegatard. Carbamazepine (CBZ) was prescribed with doses 10-20 mg/kg every 12 hours by neurologists. The patients were visited after 1, 3 and 6 months and the side effects and lab data in patients were investigated.

RESULTS

Patients were divided into two groups, 88 patients in group A (Tegretol) (50 males and 38 females) and 92 in group B (Tegatard) (51 males and 41 females). Mean age of patients was 35.39±11.17 years. There was no significant difference according to age and gender, Carbamazepine dosage, EEG recording, neuroimaging change and adverse effects of antiepileptic drug between two groups (P>0.05). Regarding the drug efficacy, in group A and B, 60 (68%) and 58 (63%) patients were seizure free after 6 month follow up; respectively. The differences between two groups were not statistically significant (P value =0.46).

CONCLUSION

Tegatard is an effective drug with similar efficacy, similar side effects and cost-effectiveness compared with Tegretol and could be used widely when indicated.

Changing understanding, perceptions, pain relief of and preference for generic medicines with patient education: An experimental intervention study

BACKGROUND

Generic medicines have been associated with less perceived efficacy and more side effects compared to brand name drugs. Educational interventions to improve individuals' negative perceptions of generic medicines show contradictory effects.

OBJECTIVE

This study investigated whether an interventional video that informs about the approval process of releasing medicines has better effects on outcomes related to perceptions and effectiveness of generic medicines in participants with headaches, in comparison with another interventional video that addresses bioequivalence between brand name and generic drugs or a control video.

METHODS

Participants with frequent tension headaches were randomized to one of three groups (one of two interventional videos or the control video). One of the interventional videos explained the process of approval of generic medicines (n = 34), the other one explained the bioequivalence between brand name and generic drugs (n = 35). The control video informed participants about the epidemiology and etiology of headaches (n = 34). After watching the video, participants treated their next two consecutive episodes of headache with a brand name and a generic analgesic in randomized order.

MAIN OUTCOME MEASURES

Self-report measures of understanding and perceptions of and preference for medicines, pain severity and side effects.

RESULTS

Linear mixed models showed that both interventional videos improved participants' understanding of generic medicines. The generic drug approval process video enhanced the perceived effectiveness, safety and quality of generic drugs. The bioequivalence video positively influenced the preference for generic drugs. The brand name and generic drug were equally effective in relieving pain in participants who watched either the generic drug approval process or the bioequivalence video.

CONCLUSIONS

Information about both, approving a switch from brand name medicines to generic counterparts and bioequivalence, can be important and should be addressed in future educational interventions.

Relationship Between Changes in Sedative-Hypnotic Medications Burden and Cognitive Outcomes in Hospitalized Older Adults

BACKGROUND

Sedative-hypnotic medications (SHMs) are frequently used in hospitalized older patients, despite undesirable effects on cognitive status. Although previous studies found a significant number of patients experience changes in SHM use during hospitalization, it is unclear which pattern of change leads to hospital-associated cognitive decline (HACD). This study tested the association between patterns of SHM change and HACD.

METHODS

This secondary analysis study included 550 patients age 70+ who were cognitively intact at admission (Short Portable Mental Status Questionnaire [SPMSQ] ≥8). HACD was defined as at least 1-point decline in SPMSQ between admission and discharge. Changes in sedative burden (SB) before and during hospitalization (average SB of all hospitalization days) were coded using the Drug Burden Index sorting study participants into four groups: without SB (n = 254), without SB changes (n = 132), increased SB (n = 82), and decreased SB (n = 82).

RESULTS

Incidence of HACD was 233/550 (42.4%). In multivariate logistic analysis controlling for demographic characteristics, length of stay, severity of acute illness, comorbidity, SB score at home, pain on admission and depression, the odds of HACD were 2.45 (95% CI: 1.16 to 5.13) among participants with increased SB, 2.10 (95% CI: 1.13 to 3.91) among participants without SB changes, compared with participants with decreased SB.

CONCLUSION

Older patients whose SB is increased or does not change are at higher risk for acquired cognitive decline than are those whose SB is reduced. Identifying patients with a potential increase in SB and intervening to reduce it may help to fight HACD.

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.

Study of mental health outcomes associated with different brands of venlafaxine at the Kumeu medical centre from January 2017 to October 2018

BACKGROUND

The antidepressant venlafaxine has been available in New Zealand for two decades and is funded by the New Zealand Drug Purchasing Agency PHARMAC. This audit aimed to determine whether change to a different funded generic formulation of venlafaxine affected patient responses to venlafaxine.

METHODS

A retrospective review of patient records for all patients at Kumeu Medical Centre, Auckland, New Zealand who received a prescription for venlafaxine since January 2017 was performed. Outcomes for patients who had experienced a stable positive clinical response to either of the two previously funded venlafaxine formulations and who were switched to the newly funded formulation were summarised.

RESULTS

Of 49 patients who had been prescribed venlafaxine, 34 patients were excluded; 15 patients had experienced a stable positive clinical response to either of the two previously funded venlafaxine formulations and switched to the newly funded formulation. Of these, 12 (80%) had poor outcomes following the change in venlafaxine formulation. Nine patients switched back to the original brand venlafaxine and showed improvement in clinical symptoms.

CONCLUSION

These cases, reported from a single general practice, should be sufficient to call attention to the possibility of loss of effectiveness for patients treated with a funded generic brand of venlafaxine, and the need for further research.

Evidence of a Media-Induced Nocebo Response Following a Nationwide Antidepressant Drug Switch

In 2017, patients on a generic or branded antidepressant venlafaxine were switched to a new generic formulation (Enlafax). In February and April 2018, two major NZ media outlets ran stories about the new generic being less effective and causing specific side effects. This study aimed to examine the effect of the media coverage on drug side effects reported to the national Centre for Adverse Reactions Monitoring (CARM) and whether the specific symptoms reported in the media increased compared to side effects not reported in the media.

We analysed monthly adverse reaction reports for Enlafax to CARM from October 2017 to June 2018 and compared adverse reports, complaints of decreased therapeutic effect and specific symptom reports before and after the media coverage using an interrupted time series analysis.

We found the number of side effects and complaints of reduced therapeutic effect increased significantly following the media stories (interruption effect = 41.83, 95% CI [25.25, 58.41], p = .003; interruption effect = 15.49, 95% CI [7.01, 23.98], p = .012, respectively). The specific side effects mentioned in the media coverage, including suicidal thoughts, also increased significantly compared to other side effects not mentioned in the media.

In the context of a drug switch, media reports of side effects appear to cause a strong nocebo response by increasing both the overall rate of side effect reporting and an increase in the specific side effects mentioned in the media coverage, including reduced drug efficacy and heightened suicidal thoughts.

The study provides further evidence that media coverage of side effects can induce a nocebo effect.

This is the first study to look at media coverage of an antidepressant brand switch.

The increase in reported adverse events was higher for those symptoms mentioned in the media reports.

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.

Bioequivalence and Therapeutic Equivalence of Generic and Brand Bupropion in Adults With Major Depression: A Randomized Clinical Trial

Controversy persists about bupropion XL 300 mg generic equivalence to brand product. A prospective, randomized, double-blinded crossover in 70 adults with major depression in stable remission taking any bupropion XL 300 mg tested bioequivalence and therapeutic equivalence of available XL 300 mg products. After a 4-week lead-in on patients' existing bupropion, four 6-week phases evaluated brand and three generics. Patients were uninformed of switching. Drug overencapsulation ensured blinding. There were no differences between any generic and brand, or between generics, in peak plasma concentration (C_max ) and area under the plasma concentration-time curve over the 24-hour dosing interval (AUC_0-24 ) for racemic bupropion or major metabolites. All generics met formal bioequivalence criteria for bupropion and metabolites. There were no differences between generics and brand, or between generics, in depression symptoms or side effects, assessed by every 3-week in-person interview and daily smartphone-based self-report. There were no differences in patients' perceptions of bupropion products. Results show three bupropion XL 300 mg generic products are both bioequivalent and not therapeutically different from brand drug and each other.

The economic impact of switching from Synthroid for the treatment of hypothyroidism

AIMS

To compare hypothyroidism-related costs for patients who continuously used Synthroid and patients who switched from Synthroid to alternative therapies.

MATERIALS AND METHODS

Truven's Health Analytics MarketScan Commercial Claims and Encounters database from January 1, 2007 to June 30, 2014 was queried for US adults diagnosed with hypothyroidism who initiated Synthroid and adhered to such therapy for at least 6 months. Propensity score matching matched continuous users of Synthroid to patients who switched from Synthroid to alternative levothyroxine agents. Kruskal-Wallis tests assessed differences between the matched cohorts in several categories of costs, including disease-related drug costs, non-drug medical costs, and total direct medical costs.

RESULTS

There were 10,159 individuals included in the study, with 7,991 continuous users of Synthroid and 2,168 switchers. After matching (n = 2,052 for each cohort), continuous use of Synthroid was associated with significantly lower hypothyroidism-related non-drug medical costs ($595 vs $1,023; p = .003) and reduced hypothyroidism-related total medical costs ($757 vs $1,132; p = .010), despite being associated with significantly higher drug costs ($161 vs $109; p < .001). Hypothyroidism-related total medical costs rose as the number of switches of hypothyroidism treatment increased, with continuous users having significantly lower hypothyroidism-related total medical costs ($757) compared with patients who switched twice ($1,179; p = .001) or three or more times ($1,268; p = .004).

LIMITATIONS

The analyses focused on continuously insured patients who were adherent to Synthroid for at least 6 months and results may not be generalizable. The reliance on claims data does not allow for clinical examination of hypothyroidism or inclusion of some factors that may be associated with outcomes. The analyses assume that all prescriptions filled are taken as prescribed.

CONCLUSIONS

Results indicate that there are significant direct economic healthcare costs associated with switching from Synthroid to alternative levothyroxine therapies, and that these costs increase as patients switch therapies more frequently.

Potential Clinical and Economic Impact of Switching Branded Medications to Generics

Switching branded to generic medications has become a common cost-containment measure. Although this is an important objective for health care systems worldwide, the impact of this practice on patient outcomes needs to be carefully considered. We reviewed the literature summarizing the potential clinical and economic consequences of switching from branded to generic medications on patient outcomes. A literature search of peer-reviewed articles published 2003-2013 using key words of "generic switching" or "substitution" was conducted using PubMed, OvidSP, and ScienceDirect. Of 30 articles identified and reviewed, most were related to the diseases of the central nervous system, especially epilepsy. Based on our review, potential impacts of switching fell into 3 broad categories: patient attitudes and adherence, clinical and safety outcomes, and cost and resource utilization. Although in many cases generics may represent an appropriate alternative to branded products, this may not always be the case. Specifically, several studies suggested that switching may negatively impact medication adherence, whereas other studies found that generic switching was associated with poorer clinical outcomes and more adverse events. In some instances, switching accomplished cost savings but did so at increased total cost of care because of increased physician visits or hospitalizations. Although in many cases generics may represent an appropriate alternative, mandatory generic switching may lead to unintended consequences, especially in certain therapeutic areas. Although further study is warranted, based on our review, it may be medically justifiable for physicians and patients to retain the right to request the branded product in certain cases.

Comparison of the effectiveness of brand-name and generic antipsychotic drugs for treating patients with schizophrenia in Taiwan

The purpose of this nationwide population-based study is to compare the long-term effectiveness of brand-name antipsychotics with generic antipsychotics for treating schizophrenia. We identified patients with schizophrenia who were prescribed antipsychotics from a random sample of one million records from Taiwan's National Health Insurance database, observed between January 1, 2000 and December 31, 2012. Only those with no prior use of antipsychotics for at least 180days were included. We selected patients who were prescribed brand-name risperidone (N=404), generic risperidone (N=145), brand-name sulpiride (N=334), or generic sulpiride (N=991). The effectiveness of the treatments researched in this study consisted of average daily doses, rates of treatment discontinuation, augmentation therapy, and psychiatric hospitalization. We found that compared to patients treated with generic risperidone, those treated with brand-name risperidone required lower daily doses (2.14mg vs. 2.61mg). However, the two groups demonstrated similar rates of treatment discontinuation, augmentation, and psychiatric hospitalization. On the other hand, in comparison with patients prescribed generic sulpiride, those treated with brand-name sulpiride not only required lower daily doses (302.72mg vs. 340.71mg) but also had lower psychiatric admission rates (adjusted hazard ratio: 0.24, 95% confidence interval: 0.10-0.56). In conclusion, for both risperidone and sulpiride, higher daily doses of the respective generic drugs were prescribed than with brand-name drugs in clinical settings. Furthermore, the brand-name sulpiride is more effective at preventing patients from hospitalization than generic sulpiride. These findings can serve as an important reference for clinical practices and healthcare economics for treating schizophrenic patients.

Advancing pharmaceuticals and patient safety in Saudi Arabia: A 2030 vision initiative

Low-quality medicines deliver sub-optimal clinical outcomes and waste precious health resources. It is important to ensure that public funds are spent on healthcare technologies that meet national regulatory bodies such as the Saudi Food and Drug Authority (SFDA), quality standards for safety, efficacy, and quality. Medicines quality is a complicated combination of pre-market regulatory specifications, appropriate sourcing of ingredients (active pharmaceutical ingredient (API), excipients, etc.), manufacturing processes, healthcare ecosystem communications, and regular and robust pharmacovigilance practices. A recent conference in Riyadh, sponsored by King Saud University, sought to discuss these issues and develop specific policy recommendations for the Saudi 2030 Vision plan. This and other efforts will require more and more creative educational programs for physicians, pharmacists, hospitals, and patients, and, most importantly evolving regulations on quality standards and oversight by Saudi health authorities.

Mixed Approach Retrospective Analyses of Suicide and Suicidal Ideation for Brand Compared with Generic Central Nervous System Drugs

INTRODUCTION

Several different types of drugs acting on the central nervous system (CNS) have previously been associated with an increased risk of suicide and suicidal ideation (broadly referred to as suicide). However, a differential association between brand and generic CNS drugs and suicide has not been reported.

OBJECTIVES

This study compares suicide adverse event rates for brand versus generic CNS drugs using multiple sources of data.

METHODS

Selected examples of CNS drugs (sertraline, gabapentin, zolpidem, and methylphenidate) were evaluated via the US FDA Adverse Event Reporting System (FAERS) for a hypothesis-generating study, and then via administrative claims and electronic health record (EHR) data for a more rigorous retrospective cohort study. Disproportionality analyses with reporting odds ratios and 95% confidence intervals (CIs) were used in the FAERS analyses to quantify the association between each drug and reported suicide. For the cohort studies, Cox proportional hazards models were used, controlling for demographic and clinical characteristics as well as the background risk of suicide in the insured population.

RESULTS

The FAERS analyses found significantly lower suicide reporting rates for brands compared with generics for all four studied products (Breslow-Day P < 0.05). In the claims- and EHR-based cohort study, the adjusted hazard ratio (HR) was statistically significant only for sertraline (HR 0.58; 95% CI 0.38-0.88).

CONCLUSION

Suicide reporting rates were disproportionately larger for generic than for brand CNS drugs in FAERS and adjusted retrospective cohort analyses remained significant only for sertraline. However, even for sertraline, temporal confounding related to the close proximity of black box warnings and generic availability is possible. Additional analyses in larger data sources with additional drugs are needed.

Association between switching antiepileptic drug products and healthcare utilization: A systematic review

AIMS

There is ongoing concern whether switching between different antiepileptic drug (AED) products may compromise patient care. We systematically reviewed changes in healthcare utilization following AED switch.

METHODS

We searched MEDLINE and EMBASE databases (1980-October 2016) for studies that assessed the effect of AED switching in patients with epilepsy on outpatient visits, emergency room visits, hospitalization and hospital stay duration.

RESULTS

A total of 14 articles met the inclusion criteria. All were retrospective studies. Four provided findings for specific AEDs only (lamotrigine, topiramate, phenytoin and divalproex), 9 presented pooled findings from multiple AEDs, and 1 study provided both specific (lamotrigine, topiramate, oxcarbazepine, and levetiracetam) and pooled findings. Three studies found an association between a switch of topiramate and an increase in healthcare utilization. Another three studies found that a brand-to-generic lamotrigine switch was not associated with an increased risk of emergently treated events (ambulance use, ER visits or hospitalization). The outcomes of the pooled AED switch studies were inconsistent; 5 studies reported an increased healthcare utilization while 5 studies did not.

CONCLUSION

Studies that have examined the association between an AED switch and a change in healthcare utilization report conflicting findings. Factors that may explain these inconsistent outcomes include inter-study differences in the type of analysis undertaken (pooled vs individual AED data), the covariates used for data adjustment, and the type of switch examined. Future medical claim database studies employing a prospective design are encouraged to address these and other factors in order to enhance inter-study comparability and extrapolation of findings.

The physical properties of generic latanoprost ophthalmic solutions are not identical

PURPOSE

To compare various characteristics of Xalatan^® and five generic latanoprost ophthalmic solutions.

METHODS

Drop size, volume, pH values, buffer capacity, viscosity, hardness of bottles and costs were determined. Drop sizes were measured in triplicates by micropipettes, and the number of drops counted in three separate bottles of each generic product was determined. pH values were measured in triplicates by a calibrated pH meter. Buffer capacity was exploited by titrating known quantities of strong base into 2.5 ml of each brand and interpolated to neutral pH. Kinematic viscosity was determined by linear regression of timed gravity flow from a vertical syringe through a 21-G cannula. The hardness of the bottles was evaluated by gradually increasing tension on a hook placed around each bottle until a drop was expelled reading the tension on an attached spring scale.

RESULTS

Drop sizes and the number of drops in the bottles varied significantly between the generic drugs. The control value of pH in the brand version (Xalatan^® ) was markedly lower compared to the generic latanoprost products. Titration of Xalatan^® to neutrality required substantially more NaOH compared to the generic latanoprost products. Finally, the viscosity revealed a significant variability between brands. Remarkable differences were found in bottle shapes, bottle hardness and costs of the latanoprost generics.

CONCLUSION

Generic latanoprost eye drops should not be considered identical to the original brand version as regards to drop size, volumes, pH values, buffer capacity, viscosity, hardness of bottles and costs. It is likely that these issues affect compliance and intraocular pressure (IOP)-lowering effect. Therefore, re-evaluation of the requirements for introducing generic eye drops seems reasonable.

Drug Brand Response and Its Impact on Compliance and Efficacy in Depression Patients

Introduction: Patient's response to drug brand is a comprehensive physiological and psychological effect which might impact the compliance and efficacy of drugs. Whether the therapeutic outcome altered on patients with brand response after they experience drug switch is not clear.

Methods: 459 outpatients with mild-to-moderate depression were divided into the imported (joint venture) drug group and the domestic drug group according to their current drug application. Two groups of patients were assessed by drug brand preference questionnaire and medication compliance questionnaire. Patients with brand preference in imported (joint venture) drugs group received rational use of limited medical resource and pharmacoeconomics education, and then switched with domestic drug for 8 weeks. Safety and efficacy were evaluated both before and after the drug switch.

Results: Overall, there were 27% of patients in imported drug group and 35% of patients in domestic drug group have brand response, respectively. About 2/3 patients in both groups showed low or no brand response. The compliance was similar in both groups with no significant difference (6.04 ± 2.08 vs. 4.74 ± 2.13, respectively, P > 0.05). The efficacy of imported drug group was significantly better than of the domestic drug group. Correlation analysis showed that in imported (joint venture) drugs group, medication compliance was closely related with brand response, but negatively correlated with age and duration. In domestic drugs group, medication compliance was independent of brand response, but closely related with education, age, and duration. After drug switch with domestic drug on patients with brand response, patients continued to maintain good antidepressant effect, and no severe adverse reaction occurred.

Conclusion: The results suggested that domestic drugs switch might be feasible for patients using imported drugs with brand response, while providing patients with rational use of drug education and psychological support. The medical staff should focus on medication education to help patients make better use of limited medical resources.

Identification of non-reported bupropion metabolites in human plasma

Bupropion and its three active metabolites exhibit clinical efficacy in the treatment of major depression, seasonal depression and smoking cessation. The pharmacokinetics of bupropion in humans is highly variable. It is not known if there are any non‐reported metabolites formed in humans in addition to the three known active metabolites. This paper reports newly identified and non‐reported metabolites of bupropion in human plasma samples. Human subjects were dosed with a single oral dose of 75 mg of an immediate release bupropion HCl tablet. Plasma samples were collected and analysed by LC–MS/MS at 0, 6 and 24 h. Two non‐reported metabolites (M1 and M3) were identified with mass‐to‐charge (m/z) ratios of 276 (M1, hydration of bupropion) and 258 (M3, hydroxylation of threo/erythrohydrobupropion) from human plasma in addition to the known hydroxybupropion, threo/erythrohydrobupropion and the glucuronidation products of the major metabolites (M2 and M4–M7). These new metabolites may provide new insight and broaden the understanding of bupropion's variability in clinical pharmacokinetics. © 2016 The Authors Biopharmaceutics & Drug Disposition Published by John Wiley & Sons Ltd.

A randomized, double-blind, cross-over, phase IV trial of oros-methylphenidate (CONCERTA(®)) and generic novo-methylphenidate ER-C (NOVO-generic)

OBJECTIVE

Attention-deficit/hyperactivity disorder (ADHD) is a common neurobehavioral disorder with onset during childhood. Multiple aspects of a child's development are hindered, in both home and school settings, with negative impacts on social, emotional, and cognitive functioning. If left untreated, ADHD is commonly associated with poor academic achievement and low occupational status, as well as increased risk of substance abuse and delinquency. The objective of this study was to evaluate adult ADHD subject reported outcomes when switched from a stable dose of CONCERTA(®) to the same dose of generic Novo-methylphenidate ER-C(®).

METHODS

Randomized, double-blind, cross-over, phase IV trial consisted of two phases in which participants with a primary diagnosis of ADHD were randomized in a 1:1 ratio to 3 weeks of treatment with CONCERTA or generic Novo-Methylphenidate ER-C. Following 3 weeks of treatment, participants were crossed-over to receive the other treatment for an additional 3 weeks. Primary efficacy was assessed through the use of the Treatment Satisfaction Questionnaire for Medication, Version II (TSQM-II).

RESULTS

Participants with ADHD treated with CONCERTA were more satisfied in terms of efficacy and side effects compared to those receiving an equivalent dose of generic Novo-Methylphenidate ER-C. All participants chose to continue with CONCERTA treatment at the conclusion of the study.

CONCLUSION

Although CONCERTA and generic Novo-Methylphenidate ER-C have been deemed bioequivalent, however the present findings demonstrate clinically and statistically significant differences between generic and branded CONCERTA. Further investigation of these differences is warranted.

The introduction of generic risperidone in Medicare Part D

OBJECTIVES

The introduction of generic second-generation antipsychotics (SGAs), starting with risperidone in July 2008, could reduce antipsychotic spending and cost-related use barriers. This study examines associations between generic risperidone use and spending and adherence after introduction among Medicare Advantage (MA) beneficiaries.

STUDY DESIGN

Historic cohort study.

METHODS

The study included MA beneficiaries receiving SGA treatment prior to July 2008. We examined antipsychotic spending using linear models, adherence (proportion of days covered ≥ 80%) using logistic models, and nonpersistence (time to first gap in antipsychotic use > 30 days) in 2009 using Cox proportional hazard models, comparing beneficiaries with versus without generic use, adjusting for individual and plan characteristics.

RESULTS

Between July 2008 and December 2009, 22.8% of beneficiaries had ≥ 1 fill of generic risperidone: 73% of those previously using branded risperidone and 6.7% of those previously using other SGAs. Beneficiaries in private fee-for-service (FFS) versus health maintenance organization (HMO) plans had lower rates of generic use (hazard ratio [HR], 0.73 [95% CI, 0.56-0.96]); however, cost-sharing levels were not associated with generic use. Compared with beneficiaries who continued using other SGAs, those who switched from other SGAs to generic risperidone in 2008 had lower out-of-pocket spending (-$214; 95% CI, -$314 to -$115), higher adherence (odds ratio, 2.34; 95% CI, 1.62-3.40) and lower rates of nonpersistence (HR, 0.56; 95% CI, 0.46-0.69) in 2009.

CONCLUSIONS

Generic use was concentrated among patients previously using branded risperidone. HMO plans appeared to be more effective at encouraging generic use than unmanaged private FFS plans; however, patient financial incentives had limited influence on switching. Additional opportunity remains to encourage greater generic SGA use, reduce spending, and potentially improve treatment adherence and outcomes.

The Impact of Generic Substitution on Health and Economic Outcomes: A Systematic Review

BACKGROUND

Generic drugs are considered therapeutically equivalent to their original counterparts and lower in acquisition costs. However, the overall impact of generic substitution (GS) on global clinical and economic outcomes has not been conclusively evaluated.

OBJECTIVE

To test whether (1) generics and original products yield the same health outcomes, and (2) generic therapies save economic resources versus original therapies.

METHODS

We performed a systematic literature review in Medline, Embase, and the Cochrane Database of Systematic Reviews to identify original studies that examine clinical or economic outcomes of GS. After standardized data extraction, reported outcomes were categorized as supporting or rejecting the hypotheses. Each reported outcome was assessed and accounted for supporting and opposing GS. One publication could provide multiple outcome comparisons.

RESULTS

We included 40 studies across ten therapeutic areas. Fourteen studies examined patients on de novo therapy; 24 studies investigated maintenance drug therapy, and two studies considered both settings. Overall, 119 outcome comparisons were examined. Of 97 clinical outcome comparisons, 67% reported no significant difference between generic drugs and their off-patent counterparts. Of 22 economic comparisons, 64% suggested that GS increased costs. Consequently, hypothesis (1) was supported but hypothesis (2) was not. We found no major differences among studies that investigated clinical outcomes with de novo or maintenance therapy.

CONCLUSION

The review suggests that clinical effects are similar after GS. However, economic savings are not guaranteed. More systematic research comparing clinical and economic outcomes with or without GS is needed to inform policy on the use of generic substitution.

Generic lamotrigine versus brand-name Lamictal bioequivalence in patients with epilepsy: A field test of the FDA bioequivalence standard

OBJECTIVE

To test the current U.S. Food and Drug Administration (FDA) bioequivalence standard in a comparison of generic and brand-name drug pharmacokinetic (PK) performance in "generic-brittle" patients with epilepsy under clinical use conditions.

METHODS

This randomized, double-blind, multiple-dose, steady-state, fully replicated bioequivalence study compared generic lamotrigine to brand-name Lamictal in "generic-brittle" patients with epilepsy (n = 34) who were already taking lamotrigine. Patients were repeatedly switched between masked Lamictal and generic lamotrigine. Intensive PK blood sampling at the end of each 2-week treatment period yielded two 12-h PK profiles for brand-name and generic forms for each patient. Steady-state area under the curve (AUC), peak plasma concentration (Cmax ), and minimum plasma concentration (Cmin ) data were subjected to conventional average bioequivalence (ABE) analysis, reference-scaled ABE analysis, and within-subject variability (WSV) comparisons. In addition, generic-versus-brand comparisons in individual patients were performed. Secondary clinical outcomes included seizure frequency and adverse events.

RESULTS

Generic demonstrated bioequivalence to brand. The 90% confidence intervals of the mean for steady-state AUC, Cmax , and Cmin for generic-versus-brand were 97.2-101.6%, 98.8-104.5%, and 93.4-101.0%, respectively. The WSV of generic and brand were also similar. Individual patient PK ratios for generic-versus-brand were similar but not identical, in part because brand-versus-brand profiles were not identical, even though subjects were rechallenged with the same product. Few subjects had seizure exacerbations or tolerability issues with product switching. One subject, however, reported 267 focal motor seizures, primarily on generic, although his brand and generic PK profiles were practically identical.

SIGNIFICANCE

Some neurologists question whether bioequivalence in healthy volunteers ensures therapeutic equivalence of brand and generic antiepileptic drugs in patients with epilepsy, who may be at increased risk for problems with brand-to-generic switching. Bioequivalence results in "generic-brittle" patients with epilepsy under clinical conditions support the soundness of the FDA bioequivalence standards. Adverse events on generic were not related to the small, allowable PK differences between generic and brand.

Regulatory and clinical aspects of psychotropic medicinal products bioequivalence

Introduction of generic medicinal products to the market has increased access to modern therapies but also enabled significant reduction in their cost, leading to containment of public expenditures on medicinal products reimbursement. The critical assessment of bioequivalence of any reference medicinal product and its counterpart is based on comparison of their rate and extent of absorption. It is assumed that two medicinal products are bioequivalent when their rate and extent of absorption do not show significant differences when administered at the same dose under similar experimental conditions. Bioequivalent medicinal products are declared to be also therapeutically equivalent and can be used interchangeably. However, despite regulatory declaration, switching from reference to generic drugs is often associated with concerns of healthcare providers about decreased treatment effectiveness or occurrence of adverse drug reactions. The aim of this article is to provide a description of rules that guide registration of generic medicinal products in the European Union and to analyze specific examples from the scientific literature concerning therapeutic equivalence of reference and generic antidepressant and antipsychotic medicinal products.

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.

Bioequivalence of Generic and Brand Name Clozapine in Korean Schizophrenic Patients: A Randomized, Two-Period, Crossover Study

OBJECTIVE

Clozapine is the treatment of choice for refractory schizophrenia. The aim of this study was to compare the pharmacokinetics of the brand name (Clozaril) formulation and a generic formulation (Clzapine) of clozapine in Korean schizophrenic patients.

METHODS

A prospective, randomized, crossover study was conducted to evaluate the steady-state pharmacokinetic profiles of Clozaril and Clzapine. Schizophrenic patients were randomized to receive either the brand name or generic formulation (100 mg twice daily) for 10 days, followed by the other formulation for 10 days. Plasma samples were collected on the last day of each treatment period.

RESULTS

Twenty-two of 28 patients (78.6%) completed the study. The mean Cmax,ss values for Clzapine and Clozaril were 524.62 and 551.18 ng/mL, and the mean AUC0-12 values were 4479.90 hr·ng/mL and 4724.56 hr·ng/mL, respectively. The 90% CI values for the natural logarithmically transformed Cmax,ss and AUC0-12 ratios (Clzapine to Clozaril) after a single oral dose (100 mg) were 0.934 (0.849-1.028) and 0.936 (0.869-1.008), respectively. Five patients (20.8%) among 24 patients who took Clzapine reported 11 adverse events and six adverse events were reported by four patients (15.4%) among 26 who took Clozaril; there were no significant differences on physical examination or in vital signs, ECG, and laboratory tests between groups.

CONCLUSION

Generic clozapine (Clzapine) appears to be bioequivalent to brand name clozapine (Clozaril).

Metabolism of bupropion by carbonyl reductases in liver and intestine

Bupropion's metabolism and the formation of hydroxybupropion in the liver by cytochrome P450 2B6 (CYP2B6) has been extensively studied; however, the metabolism and formation of erythro/threohydrobupropion in the liver and intestine by carbonyl reductases (CR) has not been well characterized. The purpose of this investigation was to compare the relative contribution of the two metabolism pathways of bupropion (by CYP2B6 and CR) in the subcellular fractions of liver and intestine and to identify the CRs responsible for erythro/threohydrobupropion formation in the liver and the intestine. The results showed that the liver microsome generated the highest amount of hydroxybupropion (Vmax = 131 pmol/min per milligram, Km = 87 μM). In addition, liver microsome and S9 fractions formed similar levels of threohydrobupropion by CR (Vmax = 98-99 pmol/min per milligram and Km = 186-265 μM). Interestingly, the liver has similar capability to form hydroxybupropion (by CYP2B6) and threohydrobupropion (by CR). In contrast, none of the intestinal fractions generate hydroxybupropion, suggesting that the intestine does not have CYP2B6 available for metabolism of bupropion. However, intestinal S9 fraction formed threohydrobupropion to the extent of 25% of the amount of threohydrobupropion formed by liver S9 fraction. Enzyme inhibition and Western blots identified that 11β-dehydrogenase isozyme 1 in the liver microsome fraction is mainly responsible for the formation of threohydrobupropion, and in the intestine AKR7 may be responsible for the same metabolite formation. These quantitative comparisons of bupropion metabolism by CR in the liver and intestine may provide new insight into its efficacy and side effects with respect to these metabolites.

Need for multicriteria evaluation of generic drug policies

Policymakers tend to focus on improving patented drug policies because they are under pressure from patients, physicians, and manufacturers to increase access to novel therapies. The success of pharmaceutical innovation over the last few decades has led to the availability of many off-patent drugs to treat disease areas with the greatest public health need. Therefore, the success of public health programs in improving the health status of the total population is highly dependent on the efficiency of generic drug policies. The objective of this article was to explore factors influencing the true efficiency of generic prescription drug policies in supporting public health initiatives in the developed world. Health care decision makers often assess the efficiency of generic drug policies by the level of price erosion and market share of generics. Drug quality, bioequivalence, in some cases drug formulations, supply reliability, medical adherence and persistence, health outcomes, and nondrug costs, however, are also attributes of success for generic drug policies. Further methodological research is needed to measure and improve the efficiency of generic drug policies. This also requires extension of the evidence base of the impact of generic drugs, partly based on real-world evidence. Multicriteria decision analysis may assist policymakers and researchers to evaluate the true value of generic drugs.

Pharmacy switch of antipsychotic medications: patient's perspective

BACKGROUND AND AIM

Several studies have raised concerns over consequences of brand-to-generic and generic-to-generic pharmacy-generated medication substitutions in psychiatric and non-psychiatric patients. The purpose of this retrospective study was to assess behavioral and emotional responses of patients with schizophrenia to antipsychotic medication substitution performed by pharmacies.

METHODS

A group of Polish ambulatory patients with schizophrenia (n = 196) chronically treated with antipsychotic medications were asked whether antipsychotic medication substitution had been proposed by a pharmacist in the last 12 months. Ninety-nine patients answering positively were administered more questions addressing the patient's emotional and behavioral response to the pharmacy proposal.

RESULTS

The most important findings of the present study can be summarized as follows: (1) approximately half of the patients were confronted with a pharmacy proposal to switch their antipsychotic medications in the last 12 months, (2) one quarter of these patients did not accept the pharmacy switch, (3) a substantial proportion of patients (>40 %) did not receive any explanation from a pharmacist offering medication substitution, (4) pharmacy-generated substitution proposals were mainly associated with negative patient attitudes and negative emotional responses, (5) substitution proposals provoked an unscheduled psychiatric visit in approx. 10 % of patients, (6) despite the negative attitudes reported by patients, the pharmacy switch rarely led to treatment discontinuation, but did provoke a change in drug dosing in 7 % of patients accepting the switch.

CONCLUSIONS

A pharmacy proposal to switch their antipsychotic medications is a relatively common experience of Polish ambulatory patients with schizophrenia. Pharmacy-generated substitution proposals are mainly associated with negative patient attitudes, but rarely lead to antipsychotic treatment discontinuation in this group of patients.

Fluoxetine suppresses AMP-activated protein kinase signaling pathway to promote hepatic lipid accumulation in primary mouse hepatocytes

In the previous study, we demonstrated that fluoxetine (FLX) regulated lipogenic and lipolytic genes to promote hepatic lipid accumulation. On this basis, underlying mechanisms were investigated by focusing on the intracellular signaling transduction in the present study using primary mouse hepatocytes. The expression of lipogenesis- and lipolysis-related genes was evaluated with the application of specific activators and inhibitors. Activation status of respective signaling pathway and the lipid accumulation in hepatocytes were analyzed. We provided evidence that AMP-activated protein kinase (AMPK) activator AICAR (5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside) significantly suppressed the increased expression of representative lipogenesis-related genes, acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS) by FLX, while increased the repressed expression of lipolysis-related genes, carboxylesterases. In the meanwhile, FLX regulated the above genes in the same way as AMPK inhibitor Compound C did. Furthermore, AICAR inhibited the proteolytic activation of SREBP1c induced by FLX, resulting in the decreased level of nuclear SREBP1c. Further studies demonstrated that FLX significantly suppressed the phosphorylation of AMPK and subsequent phosphorylation of ACC, following the inhibited phosphorylation and nuclear export of liver kinase B1 (LKB1). As a functional analysis, FLX-induced lipid accumulation in hepatocytes was repeatedly abolished by AICAR. In conclusion, FLX-induced hepatic lipid accumulation is mediated by the suppression of AMPK signaling pathway. The findings not only provide new insight into the understanding of the mechanisms for selective serotonin reuptake inhibitors-mediated dyslipidemia effects, but also suggest a novel therapeutic target to interfere.