Generic substitution of antiepileptic drugs--a survey of patients' perspectives in Germany and other German-speaking countries

Delivery problems and switch of the manufacturer of antiseizure medications - An update of an online survey of patient's experiences in Germany and other German-speaking countries

In the last decade there is an increasing frequency of sudden generic switches of antiseizure medications (ASMs) due to delivery problems. We here explored the patient's views toward generic substitution of ASMs and their experiences with delivery problems and switches of the manufacturer. A questionnaire already used in 2011 was updateded and published on the website of a patient's organisation from March 2022 until November 2022. 54.4 % of the responders reported delivery problems. Delivery problems were reported from Germany by a higher number of responders than from Switzerland. To 83.7 % of the responders the delivery problems were communicated by the pharmacists. In 41.9 % of these the delivery problems were coped by generic substitution. In 33 % of the latter breakthrough seizures occurred. 26 % of the respondents with experience of a change of the manufacturer not due to a delivery problem reported breakthrough seizures after being substituted. The majority of patients denied having been well informed about the possible consequences of a switch of the manufacturer. A thorough counselling on the low risks caused by change of the manufacturer and the need for good adherence to further reduce the risks should be part of the general information about their treatment with ASMs for people with epilepsy.

Efficacy and safety of switching from brand-name to domestic generic levetiracetam in children with epilepsy

OBJECTIVES

To study the efficacy and safety of domestic generic levetiracetam in replacement of brand-name levetiracetam in the treatment of children with epilepsy.

METHODS

A retrospective analysis was performed on the medical data of 154 children with epilepsy who received domestic generic levetiracetam in the inpatient or outpatient service of Guangdong Provincial People's Hospital from May 2019 to December 2020. Domestic generic levetiracetam and brand-name levetiracetam were compared in terms of efficacy and safety.

RESULTS

For these 154 children, the epilepsy control rate was 77.3% (119/154) at baseline. At 6 months after switching to domestic generic levetiracetam, the epilepsy control rate reached 83.8% (129/154), which showed a significant increase (P<0.05). There was no significant change in the frequency of seizures from baseline to 6 months after switching (P>0.05). The incidence of refractory epilepsy in children with no response after switching treatment was significantly higher than that in children with response (P<0.05). Before switching, only 1 child (0.6%) experienced somnolence, while after switching, 3 children (1.9%) experienced mild adverse drug reactions, including dizziness, somnolence, irritability, and bad temper.

CONCLUSIONS

Switching from brand-name to generic levetiracetam is safe and effective and holds promise for clinical application, but more prospective randomized controlled trials are required in future.

Physicians' attitudes toward generic substitutions of antiseizure drugs in epilepsy

OBJECTIVES

The safety of generic substitution of antiseizure drugs (ASDs) has been questioned for many years. This study aimed to identify physicians' attitudes to the generic substitution of ASDs in epilepsy and which factors were of significance when deciding on compound substitutions.

MATERIAL AND METHODS

A cross-sectional web-based survey was sent to neurologists and neurology residents in public health care and at private practices in two Swedish regions between February and March 2020. The 30-item survey covered drug- and patient-related factors, as well as considerations relating to practical, cost-related, and pharmacokinetic issues.

RESULTS

The total response rate was 55.8%. Respondents were generally positive to cutting costs through generic ASD utilization (74%) and prescribing generic compounds when starting a new ASD treatment (84.9%). The most substantial concern was a deterioration in seizure control (17.1%). Physicians refrained from switching if the patient wished to remain on the original compound (76.1%), had a cognitive impairment (52.5%), was on a drug with a narrow therapeutic index (47%), or had shown prior susceptibility to adverse effects (45.6%). Opinions on substitution decisions differed significantly between the Stockholm and Skåne regions. Less than one-third of the respondents were aware of supporting guidelines.

CONCLUSIONS

Neurologists generally accept the use of generic antiseizure compounds. Patient preference to remain on brand-name drug treatment was the most important factor that led to avoiding a switch. Our results may constitute material for consensus discussions to decide on quality indicators of interest for future research on substitution outcomes.

Evaluation of the In-Vitro Dissolution Permeation Systems 1 (IDAS1) as a potential tool to monitor for unexpected changes in generic medicaments in poorly regulated markets

Panama, like most Latin American countries, has insufficient regulatory safeguards to ensure the safety and efficacy of all pharmaceutical products in the market, a situation that results in a two-tier system, where affluent citizens can afford innovator products while poor citizens must consume 'generics' of uncertain quality. Given that one lot of each drug product is analyzed every five years during registration while commercial lots are not, and since most products are not bioequivalent but simply copies or similars, there is a concern that commercial and registration lots of these 'generics' may not be of the same quality. The objective of this study was to assess the ability of various in vitro quality control tests to detect difference among five amlodipine products available in the Panamanian market: four 'generics', made in various countries, and the innovator, made in Germany and used as reference listed drug in Panama (Pan-RLD). The innovator manufactured in the United States (US-RLD) was used to compare the two RLDs. The Content Uniformity test, 30-min Dissolution test and multiple-pH Dissolution Profiles did not show any difference among the products. However, the in vitro dissolution absorption system 1 (IDAS1) showed a statistically significant difference in the amount dissolved between Pan-RLD and three out of the four 'generics', and significantly lower permeated amount for all the 'generics' compared with Pan-RLD; only US-RLD was similar to Pan-RLD. Thus, IDAS1 showed promise as a potential tool that authorities in weakly regulated markets can use to monitor for possible lot-to-lot product changes, which can help improve the quality of pharmaceutical products available to their entire populations. The significance of the similarity between the innovators made in Germany and the United States and their difference from the 'generics' (manufactured in other countries) is not known but deserves investigation.

Widespread skeptic attitudes among people with epilepsy toward generic antiseizure drugs - A Swedish survey study

PURPOSE

To explore associations between the characteristics of people with epilepsy (PWE) and their attitudes toward generic substitution of antiseizure drugs (ASDs) in epilepsy.

METHODS

This was a cross-sectional survey study directed at adults with epilepsy using selected brand drugs: Keppra®, Lamictal®, Lyrica® or Topimax®. Symptoms of anxiety and depression, sense of self-efficacy, and beliefs about medicines were assessed. Caregivers were asked to answer for persons with intellectual or communicative difficulties.

RESULTS

The total response rate was 41% (n = 178). Almost half (46%) of subjects stated that they would oppose generic substitution (Gen-NEG) if suggested by their neurologist, while 71% would worry about adverse effects and/or increased seizure frequency after a putative switch. Age ≥50 increased the odds of being Gen-NEG (adjusted OR: 2.20, 95% CI: 1.18-4.11). Negative associations with both Gen-NEG and worriers were found for education level of high-school diploma or above, employment/studies, and prior experience of generic ASD switch. The proportion of worriers was much higher among caregivers (21/22) compared to subjects with epilepsy (106/156).

CONCLUSION

High proportions of PWE express concerns regarding generic substitution of ASDs. The elderly and caregivers seem to express particular concerns. Identifying ways to diminish negative outcomes and worries in connection with a switch is an important future field of research in order to ensure high quality, cost-effective health care for the most vulnerable people in our societies.

Effects of generic exchange of solid oral dosage forms in neurological disorders: a systematic review

Background Generic drug exchange is common practice in most healthcare systems. While generics certainly contribute to economic savings, the altered drug formulation might be associated with potential therapeutic problems. Given the narrow therapeutic windows in neurologic indications, any detrimental effect on the therapy can lead to significant consequences. Aim of the review This review aims to investigate potential problems related to a switch from brand-name to generic or from generic to generic drug products in patients with neurologic diseases. Method The review was conducted following the PICO framework and the PRISMA guidelines. MEDLINE and Scopus databases were searched for articles published in English and German language between January 1, 1995 and October 17, 2018. Studies included in this review were randomized controlled studies, reviews, systematic reviews, overviews, cohort studies and case-control studies. Studies excluded were letters, comments, authors view, congress or seminar papers and studies with a focus on economic impact or costs. Results were synthesized qualitatively. The primary outcomes were pharmacokinetic parameters such as the area under the curve (AUC), the peak serum concentration (c_max) or the time at which c_max is observed (t_max). Results The search identified 67 studies with a great variety of endpoints and study designs. The leading indication was epilepsy. Two small RCTs were found on lamotrigine switch. Analysis of the other studies found no significant differences in pharmacokinetic parameters when switching to generic drugs. A more heterogeneous picture was revealed regarding hospitalizations, breakthrough seizures, failure of therapy, adherence and patient concerns. Conclusion While most reports were of poor quality, lamotrigine was the drug with the best available data. Summarizing the results of the available studies, pharmacokinetic parameters of antiepileptic drugs show low deviation. In contrast, data on clinical parameters are less consistent. Some studies found increased seizure frequencies and adverse-drug events, while others showed no complications. Adherence and patient satisfaction seemed to be impaired. In daily practice, generic exchange in epilepsy should be a carefully balanced decision, conducted with great caution. Further research is needed, especially regarding neurologic indications other than epilepsy.

Development and validation of a tool to assess knowledge and attitudes towards generic medicines among students in Greece: The ATtitude TOwards GENerics (ATTOGEN) questionnaire

INTRODUCTION

The use of generic medicines is a cost-effective policy, often dictated by fiscal restraints. To our knowledge, no fully validated tool exploring the students' knowledge and attitudes towards generic medicines exists. The aim of our study was to develop and validate a questionnaire exploring the knowledge and attitudes of M.Sc. in Health Care Management students and recent alumni's towards generic drugs in Greece.

MATERIALS AND METHODS

The development of the questionnaire was a result of literature review and pilot-testing of its preliminary versions to researchers and students. The final version of the questionnaire contains 18 items measuring the respondents' knowledge and attitude towards generic medicines on a 5-point Likert scale. Given the ordinal nature of the data, ordinal alpha and polychoric correlations were computed. The sample was randomly split into two halves. Exploratory factor analysis, performed in the first sample, was used for the creation of multi-item scales. Confirmatory factor analysis and Generalized Linear Latent and Mixed Model analysis (GLLAMM) with the use of the rating scale model were used in the second sample to assess goodness of fit. An assessment of internal consistency reliability, test-retest reliability, and construct validity was also performed.

RESULTS

Among 1402 persons contacted, 986 persons completed our questionnaire (response rate = 70.3%). Overall Cronbach's alpha was 0.871. The conjoint use of exploratory and confirmatory factor analysis resulted in a six-scale model, which seemed to fit the data well. Five of the six scales, namely trust, drug quality, state audit, fiscal impact and drug substitution were found to be valid and reliable, while the knowledge scale suffered only from low inter-scale correlations and a ceiling effect. However, the subsequent confirmatory factor and GLLAMM analyses indicated a good fit of the model to the data.

CONCLUSIONS

The ATTOGEN instrument proved to be a reliable and valid tool, suitable for assessing students' knowledge and attitudes towards generic medicines.

What do people really think of generic medicines? A systematic review and critical appraisal of literature on stakeholder perceptions of generic drugs

BACKGROUND

Considerable emphasis is presently being placed on usage of generic medicines by governments focussed on the potential economic benefits associated with their use. Concurrently, there is increasing discussion in the lay media of perceived doubts regarding the quality and equivalence of generic medicines. The objective of this paper is to report the outcomes of a systematic search for peer-reviewed, published studies that focus on physician, pharmacist and patient/consumer perspectives of generic medicines.

METHODS

Literature published between January 2003 and November 2014, which is indexed in PubMed and Scopus, on the topic of opinions of physicians, pharmacists and patients with respect to generic medicines was searched, and articles within the scope of this review were appraised. Search keywords used included perception, opinion, attitude and view, along with keywords specific to each cohort.

RESULTS

Following review of titles and abstracts to identify publications relevant to the scope, 16 papers on physician opinions, 11 papers on pharmacist opinions and 31 papers on patient/consumer opinions were included in this review. Quantitative studies (n = 37) were the most common approach adopted by researchers, generally in the form of self-administered questionnaires/surveys. Qualitative methodologies (n = 15) were also reported, albeit in fewer cases. In all three cohorts, opinions of generic medicines have improved but some mistrust remains, most particularly in the patient group where there appears to be a strongly held belief that less expensive equals lower quality. Acceptance of generics appears to be higher in consumers with higher levels of education while patients from lower socioeconomic demographic groups, hence generally having lower levels of education, tend to have greater mistrust of generics.

CONCLUSIONS

A key factor in improving confidence in generic products is the provision of information and education, particularly in the areas of equivalency, regulation and dispelling myths about generic medicines (such as the belief that they are counterfeits). Further, as patient trust in their physician often overrules their personal mistrust of generic medicines, enhancing the opinions of physicians regarding generics may have particular importance in strategies to promote usage and acceptance of generic medicines in the future.

The impact on health outcomes and healthcare utilisation of switching to generic medicines consequent to reference pricing: the case of lamotrigine in New Zealand

BACKGROUND

Many countries have implemented generic reference pricing and substitution as methods of containing pharmaceutical expenditure. However, resistance to switching between medicines is apparent, especially in the case of anti-epileptic medicines.

OBJECTIVES

This study sought to exploit a nation-wide policy intervention on generic reference pricing in New Zealand to evaluate the health outcomes of patients switching from originator to generic lamotrigine, an anti-epileptic medicine.

METHODS

A retrospective study using the national health collections and prescription records was conducted comparing patients who switched from originator brand to generic lamotrigine with patients who remained on the originator brand. Primary outcome measures included switch behaviour, changes in utilisation of healthcare services at emergency departments, hospitalisations and use of specialist services, and mortality.

RESULTS

Approximately one-quarter of all patients using the originator brand of lamotrigine switched to generic lamotrigine, half of whom made the switch within 60 days of the policy implementation. Multiple switches (three or more) between generic and brand products were evident for around 10% of switchers. Switch-back rates of 3% were apparent within 30 days post-switch. No difference in heath outcome measures was associated with switching from originator lamotrigine to a generic equivalent and hence no increased costs could be found for switchers.

CONCLUSIONS

Switching from brand to generic lamotrigine is largely devoid of adverse health outcomes; however, creating an incentive to ensure a greater proportion of patients switch to generic lamotrigine is required to achieve maximal financial savings from a policy of generic reference pricing.

Are branded and generic extended-release ropinirole formulations equally efficacious? A rater-blinded, switch-over, multicenter study

The aim of this study was to compare the efficacy of the branded and a generic extended-release ropinirole formulation in the treatment of advanced Parkinson's disease (PD). Of 22 enrolled patients 21 completed the study. A rater blinded to treatment evaluated Unified Parkinson's Disease Rating Scale, Fahn-Tolosa-Marin Tremor Rating Scale, Nonmotor Symptoms Assessment Scale, and a structured questionnaire on ropinirole side effects. Besides, the patients self-administered EQ-5D, Parkinson's Disease Sleep Scale (PDSS-2), and Beck Depression Inventories. Branded and generic ropinirole treatment achieved similar scores on all tests measuring severity of motor symptoms (primary endpoint, UPDRS-III: 27.0 versus 28.0 points, P = 0.505). Based on patient diaries, the lengths of “good time periods” were comparable (10.5 and 10.0 hours for branded and generic ropinirole, resp., P = 0.670). However, generic ropinirole therapy achieved almost 3.0 hours shorter on time without dyskinesia (6.5 versus. 9.5 hours, P < 0.05) and 2.5 hours longer on time with slight dyskinesia (3.5 versus. 1.0 hours, P < 0.05) than the branded ropinirole did. Except for gastrointestinal problems, nonmotor symptoms were similarly controlled. Patients did not prefer either formulation. Although this study has to be interpreted with limitations, it demonstrated that both generic and branded ropinirole administration can achieve similar control on most symptoms of PD.