Safety of switching from brand-name to generic levetiracetam in patients with epilepsy

Safety of brand name to generic substitution of lacosamide in patients with epilepsy - A prospective single-center observational study

PURPOSE

Lacosamide is a widely used third-generation antiseizure medication. However, there is a lack of evidence regarding the safety of substituting brand-name lacosamide with its generic version. This study aimed to determine the clinical outcomes associated with switching from the brand-name to the generic form of lacosamide (LCM) in patients with epilepsy.

METHODS

This prospective observational study involved patients undergoing treatment with LCM at the university epilepsy clinic. In 2018, the price of the brand-name LCM in Poland increased up to 110-fold compared to generic products. Anticipating that most patients would opt to switch to the generic formulations due to financial constraints, we chose to follow up them prospectively to assess the safety of transitioning from the brand-name to the generic form of LCM.

RESULTS

A total of 81 patients, aged 18-62 years, diagnosed with focal epilepsy and undergoing LCM treatment at our institution, decided to switch from the brand-name (Vimpat) to generic variations (Lacosamide TEVA, Lacosamide Glenmark, and Lacosamide Accord). Following the switch, no significant difference was observed in terms of seizure frequency before and after (p = 0.55, Wilcoxon signed-rank test). Subsequently, adverse events were recorded in four patients (4.9%) during the initial follow-up visit post-switch, including somnolence (2 patients) and dizziness (2 patients). Notably, all adverse events resolved by the second follow-up visit without necessitating treatment modification. Importantly, no patient switched back to brand-name medication CONCLUSION: The generic substitution of lacosamide was found to be generally safe in our study. Nonetheless, to confirm our findings, larger prospective studies are required.

Brand-to-generic Levetiracetam Switch in Patients with Epilepsy: Seizure Control and its Predictors in a Real-world Setting

BACKGROUND: Epilepsy is a common neurological disease. Treatment with original antiepileptic drugs may result in high cost. Levetiracetam (LEV) is a broad-spectrum antiepileptic drug. Several studies showed that generic LEV is safe, effective, and saves cost. There are limited data on predictors of seizure control in persons with epilepsy treated with LEV, particularly switch therapy to generic LEV. METHODS: This study was a comparison study conducted at two tertiary care hospitals. One hospital used an original LEV, while another one switched to generic LEV. The outcomes of the study included seizure control after switching to generic LEV treatment, treatment cost, dosage of LEV, adverse events of LEV, switching therapy to original LEV, emergency room visit, and abnormal laboratory tests. These outcomes were compared between the generic and original LEV. Seizure control defined by free of seizure after switch therapy. Predictors of seizure control were analyzed by multiple logistic regression analysis. RESULTS: During the study period, there were 96 eligible patients and treated with generic LEV in 61 patients (63.54%). Regarding treatment outcomes, the generic LEV group had significantly higher proportions of seizure control (91.80% vs. 45.71%) than the original LEV group. The original LEV group had significantly higher cost than the generic LEV group (65,250 vs. 9500 Baht; p < 0.001). The final model had two factors remaining: Generic LEV and frequency of seizure before switch therapy. Generic LEV was independently associated with seizure control with adjusted OR of 6.35 (95% CI of 1.73, 23.34). CONCLUSION: Switch therapy to generic LEV is an alternative therapy with comparable efficacy, lower cost, and safe. Generic LEV and frequency of seizure attack before switch therapy to generic LEV may be related to seizure control.

Evaluating Therapeutic Equivalence of Generic and Original Levetiracetam in Patients with Epilepsy: A Retrospective Study

The brand interchangeability of antiepileptic drugs (AEDs) is a topic of debate, especially regarding their therapeutic equivalence. This study evaluates the efficacy and tolerability of generic levetiracetam compared to the brand-name equivalent in a routine clinical setting. We conducted a retrospective study, examining patients with stable seizure frequency who received generic levetiracetam after the brand-name drug. During the six-month substitution period, changes in seizure frequency, hospitalization due to seizure exacerbation, adverse events, composite outcomes related to adjusting the AED dosage, and switching back to original levetiracetam were analyzed. Seventy-five patients were enrolled; the majority (85.3%) had focal onset seizures, and almost half (49.3%) had refractory epilepsy. Six months after the substitution, the mean seizure frequency per month was not significantly different (3.15 ± 14.47 vs. 2.77 ± 11.41; p = 0.970). In patients with controlled seizures before the change, the seizure frequency increased significantly (0.56 ± 1.83 vs. 0.03 ± 0.16; p = 0.012). Adverse events occurred in six patients. We have observed recurrent seizures or adverse events from 14 days after the transition. The original drug return rates due to recurrent seizures and adverse events were 5.3% and 1.3%, respectively. Generic levetiracetam might not show therapeutic equivalence to the original molecule, especially in patients adequately controlled by the brand-name drug.

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.

Generic escitalopram initiation and substitution among Medicare beneficiaries: A new user cohort study

OBJECTIVES

To examine patterns of generic escitalopram initiation and substitution among Medicare beneficiaries.

METHODS

This retrospective new user cohort used a 5% random sample of 2013-2015 Medicare administrative claims data. Fee-for-service Medicare beneficiaries continuously enrolled in Parts A, B, and D during a 6-month washout period prior to their initial generic or brand oral escitalopram prescriptions were included (n = 12,351). The primary outcomes were generic escitalopram treatment initiation, and among brand escitalopram initiators, generic substitution within 12 months. Patient demographics, health service utilization, and prescription level factors were measured and assessed.

RESULTS

Among all escitalopram initiators, about 88.2% Medicare beneficiaries initiated generic escitalopram. Beneficiaries who were younger age, male, residing in non-Northeast regions or urban area, in the Part D plan deductible benefit phase, and filling prescriptions at community/retail pharmacies were more likely to initiate generic treatment. Among brand escitalopram initiators (n = 1,464), about 20.7% switched to generic escitalopram, 31.2% switched to another alternative antidepressant, 25.1% discontinued treatment, and 8.7% were lost to follow up or passed away within 12 months after brand initiation. Factors associated with generic escitalopram substitution included region (Midwest vs. Northeast, adjusted hazard ratio (HR) = 1.46, 95% CI = 1.04-2.05), pre-index hospitalization (HR = 1.31; 95% CI = 1.16-1.48) and lower escitalopram average daily dosage (HR = 0.97; 95% CI = 0.95-0.99).

CONCLUSIONS

In 2013-2015, almost 90% Medicare beneficiaries initiated generic escitalopram treatment. Among brand escitalopram initiators, about 1 in 5 patients switched to generic escitalopram within 1 year, as compared to 1 in 4 or 1 in 3 who discontinued current or switched to alternative treatment, respectively. Medicare beneficiary's geographic region was independently associated with generic escitalopram initiation and substitution. Findings from this study not only provide up-to-date evidence in generic escitalopram use patterns among Medicare population, but also can guide educational and practice interventions to further increase generic escitalopram use.

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.

Population Pharmacokinetics and Dosing Recommendations of Levetiracetam in Adult and Elderly Patients With Epilepsy

The objective was to develop and externally validate a population pharmacokinetic model of levetiracetam in adult and elderly patients with epilepsy, and to perform dosing simulations to propose individualized dosing regimens more likely to achieve therapeutic concentrations. This prospective study included 367 plasma samples from 107 patients receiving oral levetiracetam. Samples were analyzed by HPLC-UV. Pharmacokinetic data, as well as patient demographic, clinical characteristics, other drug therapy, and the use of innovator or generic products of levetiracetam, were collected. Population modeling was performed with NONMEM and included internal and external validations of the final model. Simulations were used to propose optimized dosing regimens. The pharmacokinetics of levetiracetam was described by a one-compartment model with first-order absorption and linear elimination. Body surface area had a significant effect on the apparent volume of distribution, as did creatinine clearance (CrCL) over the drug clearance (p < 0.01). The final model performed adequately during external validation testing. The final model showed a better predictive performance. Dosing simulations support 1000 mg 12-hourly dosing of levetiracetam for patients with CrCL ~60-75 mL/min with higher dose needed for higher values (1500 mg 12-hourly for CrCL ~93-111 mL/min). Dosing regimens should be personalized to the patient's CrCL to maximize the likelihood of therapeutic concentrations.

Nocebo in Biosimilars and Generics in Neurology: A Systematic Review

Background: Nocebo refers to adverse events related to patients’ negative expectations and previous experiences, mediated by several neurobiological pathways within the brain. It is common among neurological patients and affects adherence and treatment outcomes, representing a real clinical challenge.

Methods: We conducted a systematic search based on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines in MEDLINE database, using several keywords for studies that can be processed to investigate the magnitude of nocebo in generics and biosimilars used in the most common neurological diseases. The aim was to estimate its size and suggest strategies to minimize its prevalence in clinical trials and practice.

Results: Of a total of 2,606 identified articles, after criteria-based selection, 35 studies were included for analysis. Overall, there was vast heterogeneity across the studies concerning population, study design, and outcomes. Nocebo response could be estimated only in one double-blind randomized trial of generic glatiramer acetate in relapsing remitting multiple sclerosis that included a placebo arm. In this trial, no significant differences observed between the three arms (innovator, bioequivalent, and placebo) in favorable and unfavorable outcomes. In the open-label phase of the trial, an increased withdrawal rate was recorded in patients switched from placebo to bioequivalent (8.4%) that may be related to nocebo. In other open-label and real-world studies evaluating biosimilars or generics for brain disorders, a similar indirect nocebo effect is assuming by several investigators. Also, knowledge gaps between health-care providers and patients exist towards generics and biosimilars.

Conclusions: Despite its presence, the true burden of the nocebo response and effect cannot be accurately estimated in existing studies with generics and biosimilars in neurological diseases. Targeted strategies for clinical trials’ design are needed in order to measure the exact nocebo’s size.